Polymer compositions, polymer films and methods and precursors for forming same

Science.gov (United States)

Klaehn, John R; Peterson, Eric S; Orme, Christopher J

2013-09-24

Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

Ionic polymer metal composites with polypyrrole-silver electrodes

Science.gov (United States)

Cellini, F.; Grillo, A.; Porfiri, M.

2015-03-01

Ionic polymer metal composites (IPMCs) are a class of soft active materials that are finding increasing application in robotics, environmental sensing, and energy harvesting. In this letter, we demonstrate the fabrication of IPMCs via in-situ photoinduced polymerization of polypyrrole-silver electrodes on an ionomeric membrane. The composition, morphology, and sheet resistance of the electrodes are extensively characterized through a range of experimental techniques. We experimentally investigate IPMC electrochemistry through electrochemical impedance spectroscopy, and we propose a modified Randle's model to interpret the impedance spectrum. Finally, we demonstrate in-air dynamic actuation and sensing and assess IPMC performance against more established fabrication methods. Given the simplicity of the process and the short time required for the formation of the electrodes, we envision the application of our technique in the development of a rapid prototyping technology for IPMCs.

Composite materials obtained by the ion-plasma sputtering of metal compound coatings on polymer films

Science.gov (United States)

Khlebnikov, Nikolai; Polyakov, Evgenii; Borisov, Sergei; Barashev, Nikolai; Biramov, Emir; Maltceva, Anastasia; Vereshchagin, Artem; Khartov, Stas; Voronin, Anton

2016-01-01

In this article, the principle and examples composite materials obtained by deposition of metal compound coatings on polymer film substrates by the ion-plasma sputtering method are presented. A synergistic effect is to obtain the materials with structural properties of the polymer substrate and the surface properties of the metal deposited coatings. The technology of sputtering of TiN coatings of various thicknesses on polyethylene terephthalate films is discussed. The obtained composites are characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) is shown. The examples of application of this method, such as receiving nanocomposite track membranes and flexible transparent electrodes, are considered.

Polymer-Derived In- Situ Metal Matrix Composites Created by Direct Injection of a Liquid Polymer into Molten Magnesium

Science.gov (United States)

Sudarshan; Terauds, Kalvis; Anilchandra, A. R.; Raj, Rishi

2014-02-01

We show that a liquid organic precursor can be injected directly into molten magnesium to produce nanoscale ceramic dispersions within the melt. The castings made in this way possess good resistance to tensile deformation at 673 K (400 °C), confirming the non-coarsening nature of these dispersions. Direct liquid injection into molten metals is a significant step toward inserting different chemistries of liquid precursors to generate a variety of polymer-derived metal matrix composites.

Electroless formation of conductive polymer-metal nanostructured composites at boundary of two immiscible solvents. Morphology and properties

International Nuclear Information System (INIS)

Gniadek, Marianna; Donten, Mikolaj; Stojek, Zbigniew

2010-01-01

Formation of polypyrrole (PPy) with metallic inclusions was carried out at the interface between the aqueous phase containing an oxidizer and an organic solution of the monomer. A variety of the polymer-metal composites were obtained in the system. When the oxidizers were silver- and gold salts the obtained material contained from 4 to 9 at.% of metal. In the case of Ag + oxidant the structure of the metallic silver objects varied and included beads and ultra thin wires covered by polymer film, nanocrystals, micrometer cuboid monocrystals and microplates. Metallic gold practically appeared only in one structure-granules. The granules of Au incorporated into PPy were porous and made of very fine flat crystals of thickness in the nanometer range. The use of copper salts never led to the formation of metallic species in the composite. The influence of selected process parameters such as temperature and concentration of the reactants on the polymerization reaction was investigated. The composites with metallic nanoobjects were found to be better catalysts for the electrooxidation of ascorbic acids compared to pure polypyrrole. SEM, X-ray diffractometry, Raman spectroscopy and voltammetry were used in the investigation.

Electroless formation of conductive polymer-metal nanostructured composites at boundary of two immiscible solvents. Morphology and properties

Energy Technology Data Exchange (ETDEWEB)

Gniadek, Marianna [Department of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw (Poland); Donten, Mikolaj, E-mail: donten@chem.uw.edu.p [Department of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw (Poland); Stojek, Zbigniew, E-mail: stojek@chem.uw.edu.p [Department of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw (Poland)

2010-11-01

Formation of polypyrrole (PPy) with metallic inclusions was carried out at the interface between the aqueous phase containing an oxidizer and an organic solution of the monomer. A variety of the polymer-metal composites were obtained in the system. When the oxidizers were silver- and gold salts the obtained material contained from 4 to 9 at.% of metal. In the case of Ag{sup +} oxidant the structure of the metallic silver objects varied and included beads and ultra thin wires covered by polymer film, nanocrystals, micrometer cuboid monocrystals and microplates. Metallic gold practically appeared only in one structure-granules. The granules of Au incorporated into PPy were porous and made of very fine flat crystals of thickness in the nanometer range. The use of copper salts never led to the formation of metallic species in the composite. The influence of selected process parameters such as temperature and concentration of the reactants on the polymerization reaction was investigated. The composites with metallic nanoobjects were found to be better catalysts for the electrooxidation of ascorbic acids compared to pure polypyrrole. SEM, X-ray diffractometry, Raman spectroscopy and voltammetry were used in the investigation.

Antimicrobial Polymers with Metal Nanoparticles

Science.gov (United States)

Palza, Humberto

2015-01-01

Metals, such as copper and silver, can be extremely toxic to bacteria at exceptionally low concentrations. Because of this biocidal activity, metals have been widely used as antimicrobial agents in a multitude of applications related with agriculture, healthcare, and the industry in general. Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives. Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc. One recent route to further extend the antimicrobial applications of these metals is by their incorporation as nanoparticles into polymer matrices. These polymer/metal nanocomposites can be prepared by several routes such as in situ synthesis of the nanoparticle within a hydrogel or direct addition of the metal nanofiller into a thermoplastic matrix. The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms. PMID:25607734

Nanostructural self-organization and dynamic adaptation of metal-polymer tribosystems

Science.gov (United States)

Mashkov, Yu. K.

2017-02-01

The results of investigating the effect of nanosize modifiers of a polymer matrix on the nanostructural self-organization of polymer composites and dynamic adaptation of metal-polymer tribosystems, which considerably affect the wear resistance of polymer composite materials, have been analyzed. It has been shown that the physicochemical nanostructural self-organization processes are developed in metal-polymer tribosystems with the formation of thermotropic liquid-crystal structures of the polymer matrix, followed by the transition of the system to the stationary state with a negative feedback that ensures dynamic adaptation of the tribosystem to given operating conditions.

The diaphragms of fenestrated endothelia: gatekeepers of vascular permeability and blood composition.

Science.gov (United States)

Stan, Radu V; Tse, Dan; Deharvengt, Sophie J; Smits, Nicole C; Xu, Yan; Luciano, Marcus R; McGarry, Caitlin L; Buitendijk, Maarten; Nemani, Krishnamurthy V; Elgueta, Raul; Kobayashi, Takashi; Shipman, Samantha L; Moodie, Karen L; Daghlian, Charles P; Ernst, Patricia A; Lee, Hong-Kee; Suriawinata, Arief A; Schned, Alan R; Longnecker, Daniel S; Fiering, Steven N; Noelle, Randolph J; Gimi, Barjor; Shworak, Nicholas W; Carrière, Catherine

2012-12-11

Fenestral and stomatal diaphragms are endothelial subcellular structures of unknown function that form on organelles implicated in vascular permeability: fenestrae, transendothelial channels, and caveolae. PV1 protein is required for diaphragm formation in vitro. Here, we report that deletion of the PV1-encoding Plvap gene in mice results in the absence of diaphragms and decreased survival. Loss of diaphragms did not affect the fenestrae and transendothelial channels formation but disrupted the barrier function of fenestrated capillaries, causing a major leak of plasma proteins. This disruption results in early death of animals due to severe noninflammatory protein-losing enteropathy. Deletion of PV1 in endothelium, but not in the hematopoietic compartment, recapitulates the phenotype of global PV1 deletion, whereas endothelial reconstitution of PV1 rescues the phenotype. Taken together, these data provide genetic evidence for the critical role of the diaphragms in fenestrated capillaries in the maintenance of blood composition. Copyright © 2012 Elsevier Inc. All rights reserved.

Controlled growth of Au nanoparticles in co-evaporated metal/polymer composite films and their optical and electrical properties

Science.gov (United States)

Takele, H.; Schürmann, U.; Greve, H.; Paretkar, D.; Zaporojtchenko, V.; Faupel, F.

2006-02-01

Nanocomposite films containing Au nanoparticles embedded in a polymer matrix were prepared by vapour phase co-deposition of Au and polymers (Teflon AF and Poly(α -methylstyrene)) in high vacuum. The microstructure of the composite materials as well as metal content strongly depend on the condensation coefficient of the Au atoms, the deposition rates of the components, the substrate temperature, and the type of polymer matrix. The condensation coefficient, which varies between 0.03 and 1, was determined from energy dispersive X-ray spectrometer (EDX) and surface profilometry. It is shown that the microstructure of nanocomposites (size, size distribution, and interparticle separation of metal clusters), which was determined by transmission electron microscopy, can be controlled by the deposition parameters and the choice of polymer matrix. The optical absorption in the visible region due to the particle plasmon resonance has a strong dependence on the metal filling factor. The correlation between the microstructure of nanocomposites and optical properties, studied using UV-Vis spectroscopy, was also established. Further more, the electrical properties of the composites were studied as a function of the metal volume fraction. It was observed that the nanocomposite films exhibit a percolation threshold at a metal volume fraction of 0.43 and 0.20 for gold nanoclusters in Teflon AF and Poly(α-methylstyrene), respectively.

Fused filament 3D printing of ionic polymer-metal composites (IPMCs)

International Nuclear Information System (INIS)

Carrico, James D; Traeden, Nicklaus W; Leang, Kam K; Aureli, Matteo

2015-01-01

This paper describes a new three-dimensional (3D) fused filament additive manufacturing (AM) technique in which electroactive polymer filament material is used to build soft active 3D structures, layer by layer. Specifically, the unique actuation and sensing properties of ionic polymer-metal composites (IPMCs) are exploited in 3D printing to create electroactive polymer structures for application in soft robotics and bio-inspired systems. The process begins with extruding a precursor material (non-acid Nafion precursor resin) into a thermoplastic filament for 3D printing. The filament is then used by a custom-designed 3D printer to manufacture the desired soft polymer structures, layer by layer. Since at this stage the 3D-printed samples are not yet electroactive, a chemical functionalization process follows, consisting in hydrolyzing the precursor samples in an aqueous solution of potassium hydroxide and dimethyl sulfoxide. Upon functionalization, metal electrodes are applied on the samples through an electroless plating process, which enables the 3D-printed IPMC structures to be controlled by voltage signals for actuation (or to act as sensors). This innovative AM process is described in detail and the performance of 3D printed IPMC actuators is compared to an IPMC actuator fabricated from commercially available Nafion sheet material. The experimental results show comparable performance between the two types of actuators, demonstrating the potential and feasibility of creating functional 3D-printed IPMCs. (paper)

Fused filament 3D printing of ionic polymer-metal composites (IPMCs)

Science.gov (United States)

Carrico, James D.; Traeden, Nicklaus W.; Aureli, Matteo; Leang, Kam K.

2015-12-01

This paper describes a new three-dimensional (3D) fused filament additive manufacturing (AM) technique in which electroactive polymer filament material is used to build soft active 3D structures, layer by layer. Specifically, the unique actuation and sensing properties of ionic polymer-metal composites (IPMCs) are exploited in 3D printing to create electroactive polymer structures for application in soft robotics and bio-inspired systems. The process begins with extruding a precursor material (non-acid Nafion precursor resin) into a thermoplastic filament for 3D printing. The filament is then used by a custom-designed 3D printer to manufacture the desired soft polymer structures, layer by layer. Since at this stage the 3D-printed samples are not yet electroactive, a chemical functionalization process follows, consisting in hydrolyzing the precursor samples in an aqueous solution of potassium hydroxide and dimethyl sulfoxide. Upon functionalization, metal electrodes are applied on the samples through an electroless plating process, which enables the 3D-printed IPMC structures to be controlled by voltage signals for actuation (or to act as sensors). This innovative AM process is described in detail and the performance of 3D printed IPMC actuators is compared to an IPMC actuator fabricated from commercially available Nafion sheet material. The experimental results show comparable performance between the two types of actuators, demonstrating the potential and feasibility of creating functional 3D-printed IPMCs.

Synthesis by plasma of polymer-metal materials

International Nuclear Information System (INIS)

Fernandez R, G.

2004-01-01

The objective of this work is the design of an experimental set-up to synthesize polymer- metal composites by plasma with versatility in the conditions of synthesis. The main components are a vacuum system capable to reach up to 10 -2 mbar and valves and accessories to control the pressure in the system. In order to generate the electrical discharges and the plasma, an electrical circuit with an inductive connection at 13.56 MHz of frequency was constructed. The electric field partially ionizes the reactor atmosphere where the polymer-metal composites were synthesized. The reactor has two metallic electrodes, one in front of the other, where the particles electrically charged collide against the electrodes producing ablation on them. The polymer-metal composites were synthesized by means of an inductive connection at 13.56 MHz. Aniline, 3-chlorine-ethylene and electrodes of silver (Ag) and copper (Cu) were used in a cylindrical reactor coupled with an external coil to generate glow discharges. The average pressures were 6.15 X 10 -1 and 5.2 X 10 -1 mbar for the synthesis of Poly aniline (P An) and Poly chloroethylene (PE-CI), respectively. The synthesis was performed during 60 and 180 minutes for P An and PE-CI, respectively. The polymers were formed, as films, with an average thickness of 6.42 μm for P An and, in the case of PE-CI, with an approximately growing rate of 14 ηm/W. The power in the syntheses was 30, 50, 70 and 90 W for P An and 50, 100, 120, 140 170, and 200 W for PE-CI. The characterization of the polymer-metal composites was done by energy dispersive spectroscopy to study the composition and the relation of the elements involved in the synthesis. The morphology of the films was studied by means of scanning electron microscopy. The infrared analysis (IR) was done to study the chemicals bonds and the structure of these polymers. Another important study in these materials was the behavior of the electrical conductivity (σ), which was complemented

Real-time detection of metal ions using conjugated polymer composite papers.

Science.gov (United States)

Lee, Ji Eun; Shim, Hyeon Woo; Kwon, Oh Seok; Huh, Yang-Il; Yoon, Hyeonseok

2014-09-21

Cellulose, a natural polymeric material, has widespread technical applications because of its inherent structural rigidity and high surface area. As a conjugated polymer, polypyrrole shows practical potential for a diverse and promising range of future technologies. Here, we demonstrate a strategy for the real-time detection and removal of metal ions with polypyrrole/cellulose (PPCL) composite papers in solution. Simply, the conjugated polymer papers had different chemical/physical properties by applying different potentials to them, which resulted in differentiable response patterns and adsorption efficiencies for individual metal ions. First, large-area PPCL papers with a diameter of 5 cm were readily obtained via vapor deposition polymerization. The papers exhibited both mechanical flexibility and robustness, in which polypyrrole retained its redox property perfectly. The ability of the PPCL papers to recognize metal ions was examined in static and flow cells, in which real-time current change was monitored at five different applied potentials (+1, +0.5, 0, -0.5, and -1 V vs. Ag/AgCl). Distinguishable signals in the PPCL paper responses were observed for individual metal ions through principal component analysis. Particularly, the PPCL papers yielded unique signatures for three metal ions, Hg(ii), Ag(i), and Cr(iii), even in a real sample, groundwater. The sorption of metal ions by PPCL papers was examined in the flow system. The PPCL papers had a greatly superior adsorption efficiency for Hg(ii) compared to that of the other metal ions. With the strong demand for the development of inexpensive, flexible, light-weight, and environmentally friendly devices, the fascinating characteristics of these PPCL papers are likely to provide good opportunities for low-cost paper-based flexible or wearable devices.

Modeling and control of a self-sensing polymer metal composite actuator

International Nuclear Information System (INIS)

Nam, Doan Ngoc Chi; Ahn, Kyoung Kwan

2014-01-01

An ion polymer metal composite (IPMC) is an electro-active polymer (EAP) that bends in response to a small applied electrical field as a result of mobility of cations in the polymer network and vice versa. One drawback in the use of an IPMC is the sensing problem for such a small size actuator. The aim of this paper is to develop a physical model for a self-sensing IPMC actuator and to verify its applicability for practical position control. Firstly, ion dynamics inside a polymer membrane is investigated with an asymmetric solution in the presence of distributed surface resistance. Based on this analysis, a modified equivalent circuit and a simple configuration to realize the self-sensing IPMC actuator are proposed. Mathematical modelling and experimental evaluation indicate that the bending curvature can be obtained accurately using several feedback voltage signals along with the IPMC length. Finally, the controllability of the developed self-sensing IPMC actuator is investigated using a robust position control. Experimental results prove that the self-sensing characteristics can be applied in engineering control problems to provide a more convenient sensing method for IPMC actuating systems. (paper)

Polymer - (BEDT-TTF) polyiodide composites

Energy Technology Data Exchange (ETDEWEB)

Ulanski, J [Polymer Inst., Technical Univ. of Lodz (Poland); Glowacki, I [Polymer Inst., Technical Univ. of Lodz (Poland); Kryszewski, M [Polymer Inst., Technical Univ. of Lodz (Poland); Jeszka, J K [Center of Molecular and Macromolecular Studies, Lodz (Poland); Tracz, A [Center of Molecular and Macromolecular Studies, Lodz (Poland); Laukhina, E [Inst. of Chemical Physics, Chernogolovka (Russian Federation)

1993-03-29

Preparation and properties of reticulate doped polymers containing BEDT-TTF polyiodide crystalline network are discussed. The highly conducting films are obtained using different methods, including recently developed one in which oxidation of the donor with iodine and crystallization of the resulting salt take place simultaneously in situ, in the swollen polymer matrix. It was found that the temperature dependence of conductivity of the separated microcrystal grown in the film exhibits metallic character with a maximum around 100K. The conductivity of the as-obtained composite increases with temperature up to ca. 120K with an activation energy of ca. 50 meV, then levels off. Annealing of the composites in order to transform the BEDT-TTF polyiodide crystalites into superconducting [beta][sup *]-phase causes dramatic changes in the conductivity behaviour; the [sigma](T) dependence of the composite switches from semiconductor- to metal-like. Stability of the films at ambient conditions is good. (orig.)

Gas-phase synthesis of magnetic metal/polymer nanocomposites

Science.gov (United States)

Starsich, Fabian H. L.; Hirt, Ann M.; Stark, Wendelin J.; Grass, Robert N.

2014-12-01

Highly magnetic metal Co nanoparticles were produced via reducing flame spray pyrolysis, and directly coated with an epoxy polymer in flight. The polymer content in the samples varied between 14 and 56 wt% of nominal content. A homogenous dispersion of Co nanoparticles in the resulting nanocomposites was visualized by electron microscopy. The size and crystallinity of the metallic fillers was not affected by the polymer, as shown by XRD and magnetic hysteresis measurements. The good control of the polymer content in the product nanocomposite was shown by elemental analysis. Further, the successful polymerization in the gas phase was demonstrated by electron microscopy and size measurements. The presented effective, dry and scalable one-step synthesis method for highly magnetic metal nanoparticle/polymer composites presented here may drastically decrease production costs and increase industrial yields.

Electromechanical modelling of tapered ionic polymer metal composites transducers

Directory of Open Access Journals (Sweden)

Rakesha Chandra Dash

2016-09-01

Full Text Available Ionic polymer metal composites (IPMCs are relatively new smart materials that exhibit a bidirectional electromechanical coupling. IPMCs have large number of important engineering applications such as micro robotics, biomedical devices, biomimetic robotics etc. This paper presents a comparison between tapered and uniform cantilevered Nafion based IPMCs transducer. Electromechanical modelling is done for the tapered beam. Thickness can be varied according to the requirement of force and deflection. Numerical results pertaining to the force and deflection characteristics of both type IPMCs transducer are obtained. It is shown that the desired amount of force and deflections for tapered IPMCs can be achieved for a given voltage. Different fixed end (t0 and free end (t1 thickness values have been taken to justify the results using MATLAB.

Gas Phase Sensing of Alcohols by Metal Organic Framework–Polymer Composite Materials

Science.gov (United States)

2017-01-01

Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH2-MIL-53(Al) were dispersed in a Matrimid polymer matrix with different weight ratios (0–100 wt %) and drop-casted on planar capacitive transducer devices. These coated devices were electrically analyzed using impedance spectroscopy and investigated for their sensing properties toward the detection of a series of alcohols and water in the gas phase. The measurements indicated a reversible and reproducible response in all devices. Sensor devices containing 40 wt % NH2-MIL-53(Al) in Matrimid showed a maximum response for methanol and water. The sensor response time slowed down with increasing MOF concentration until 40 wt %. The half time of saturation response (τ0.5) increased by ∼1.75 times for the 40 wt % composition compared to devices coated with Matrimid only. This is attributed to polymer rigidification near the MOF/polymer interface. Higher MOF loadings (≥50 wt %) resulted in brittle coatings with a response similar to the 100 wt % MOF coating. Cross-sensitivity studies showed the ability to kinetically distinguish between the different alcohols with a faster response for methanol and water compared to ethanol and 2-propanol. The observed higher affinity of the pure Matrimid polymer toward methanol compared to water allows also for a higher uptake of methanol in the composite matrices. Also, as indicated by the sensing studies with a mixture of water and methanol, the methanol uptake is independent of the presence of water up to 6000 ppm of water. The NH2-MIL-53(Al) MOFs dispersed in the Matrimid matrix show a sensitive and reversible capacitive response, even in the presence of water. By tuning the precise compositions, the affinity kinetics and overall affinity can be tuned, showing

A mechanical model of a non-uniform ionomeric polymer metal composite actuator

International Nuclear Information System (INIS)

Anton, Mart; Aabloo, Alvo; Punning, Andres; Kruusmaa, Maarja

2008-01-01

This paper describes a mechanical model of an IPMC (ionomeric polymer metal composite) actuator in a cantilever beam configuration. The main contribution of our model is that it gives the most detailed description reported so far of the quasistatic mechanical behaviour of the actuator with non-uniform bending at large deflections. We also investigate a case where part of an IPMC actuator is replaced with a rigid elongation and demonstrate that this configuration would make the actuator behave more linearly. The model is experimentally validated with MuscleSheet(TM) IPMCs, purchased from BioMimetics Inc

Development of artificial muscles based on electroactive ionomeric polymer-metal composites.

Science.gov (United States)

Hirano, Laos A; Escote, Márcia T; Martins-Filho, Luiz S; Mantovani, Gerson L; Scuracchio, Carlos H

2011-05-01

This work contextualizes the research of materials that can be applied as artificial muscles. The main motivation of this research is the importance of the development of mechatronic systems for the replacement of traditional devices of actuation and motion based on rotational electrical motors by other devices that reproduce biological muscle movements. Electroactive polymers (EAPs) are materials that respond to electric stimuli with shape and/or dimension changes, and accomplish movements that are smooth enough to mimic biological muscles. Among EAPs, the ionomeric polymer-metal composites (IPMCs) are an interesting alternative to biomimetic devices due to large displacements when submitted to low applied voltage. This article presents a brief review of IPMCs, a sample preparation procedure, and some electromechanical experimental results. We also discuss the applicability of this technology in medical devices and as artificial muscles. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Effect of Metallic Additives to Polymer Matrix on Properties of Composite Adhesives Dedicated for Light Metal Joining

Directory of Open Access Journals (Sweden)

Mamala A.

2017-12-01

Full Text Available The most recent and promising trends in development of renewable sources of energy are Combined Heat and Power (CHP systems. The newest solutions from this field are hybrid compact solar panels. The correct operation of both systems, i.e. the photovoltaic panel and the heat exchanger requires an effective connection between the two. The adhesives utilized to interconnect above elements should provide a stable and hermetic joint able to withstand mechanical and thermal impacts of the surrounding environment factors. The paper presents the research results over the impact of the type and the amount of reinforcing phase on the physical and mechanical properties of epoxy resin matrix composites reinforced with particles of non-ferrous metals (Ag, Cu, W, Al, dedicated as adhesives for connections between photovoltaic panels and heat exchangers. Based on the experimental findings the usefulness of classical analytic models for valuation of polymer-metal composites properties was validated.

Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant.

Science.gov (United States)

Petersen, Richard C

2011-05-03

Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P engineering potential.

A model for ionic polymer metal composites as sensors

Science.gov (United States)

Bonomo, C.; Fortuna, L.; Giannone, P.; Graziani, S.; Strazzeri, S.

2006-06-01

This paper introduces a comprehensive model of sensors based on ionic polymer metal composites (IPMCs) working in air. Significant quantities ruling the sensing properties of IPMC-based sensors are taken into account and the dynamics of the sensors are modelled. A large amount of experimental evidence is given for the excellent agreement between estimations obtained using the proposed model and the observed signals. Furthermore, the effect of sensor scaling is investigated, giving interesting support to the activities involved in the design of sensing devices based on these novel materials. We observed that the need for a wet environment is not a key issue for IPMC-based sensors to work well. This fact allows us to put IPMC-based sensors in a totally different light to the corresponding actuators, showing that sensors do not suffer from the same drawbacks.

Modified resistivity-strain behavior through the incorporation of metallic particles in conductive polymer composite fibers containing carbon nanotubes

NARCIS (Netherlands)

Lin, L.; Deng, H.; Gao, X.; Zhang, S.M.; Bilotti, E.; Peijs, A.A.J.M.; Fu, Q.

2013-01-01

Eutectic metal particles and carbon nanotubes are incorporated into a thermoplastic polyurethane matrix through a simple but efficient method, melt compounding, to tune the resistivity-strain behavior of conductive polymer composite (CPC) fibers. Such a combination of conductive fillers is rarely

Ion-Selective Ionic Polymer Metal Composite (IPMC) actuator based on crown ether containing sulfonated Poly(Arylene Ether Ketone)

NARCIS (Netherlands)

Tas, S.; Zoetebier, B.; Sukas, O.S.; Bayraktar, M.; Hempenius, M.; Vancso, G.J.; Nijmeijer, K.

2017-01-01

This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane

Quantitative radiographic analysis of fiber reinforced polymer composites.

Science.gov (United States)

Baidya, K P; Ramakrishna, S; Rahman, M; Ritchie, A

2001-01-01

X-ray radiographic examination of the bone fracture healing process is a widely used method in the treatment and management of patients. Medical devices made of metallic alloys reportedly produce considerable artifacts that make the interpretation of radiographs difficult. Fiber reinforced polymer composite materials have been proposed to replace metallic alloys in certain medical devices because of their radiolucency, light weight, and tailorable mechanical properties. The primary objective of this paper is to provide a comparable radiographic analysis of different fiber reinforced polymer composites that are considered suitable for biomedical applications. Composite materials investigated consist of glass, aramid (Kevlar-29), and carbon reinforcement fibers, and epoxy and polyether-ether-ketone (PEEK) matrices. The total mass attenuation coefficient of each material was measured using clinical X-rays (50 kev). The carbon fiber reinforced composites were found to be more radiolucent than the glass and kevlar fiber reinforced composites.

Synthesis of biocidal polymers containing metal NPs using an electron beam

International Nuclear Information System (INIS)

Choi, Kwonyong; Kim, Seong-Eun; Kim, Hee-Yeon; Yoon, Jeyong; Lee, Jong-Chan

2012-01-01

Metal containing antibacterial polymers were prepared by the polymerization of methylmethacrylate and methacrylic acid with copper or zinc. When the thin film of the polymers coated on a glass was irradiated with an electron beam, nanoparticles were obtained. It was found that these polymers exhibited a potent antibacterial activity against the Gram-negative bacteria, Escherichia coli. The metal containing polymers showed a 99.999% (5.0 logs) reduction in E. coli at a contact time of 12 h. In addition, polymers had a good antifouling effect against marine organisms. - Graphical abstract: Biocidal activity of Cu nanoparticle/polymer composite film against Gram-negative bacteria. Highlights: ► Metal containing antibacterial polymers were prepared with copper. ► Using the electron beam, nanoparticles were obtained. ► It was found that these polymers exhibited potent biocidal activity against E. coli. ► The metal containing polymers showed a 99.999% reduction of E. coli.

Polymer-supported metals and metal oxide nanoparticles: synthesis, characterization, and applications

International Nuclear Information System (INIS)

Sarkar, Sudipta; Guibal, E.; Quignard, F.; SenGupta, A. K.

2012-01-01

Metal and metal oxide nanoparticles exhibit unique properties in regard to sorption behaviors, magnetic activity, chemical reduction, ligand sequestration among others. To this end, attempts are being continuously made to take advantage of them in multitude of applications including separation, catalysis, environmental remediation, sensing, biomedical applications and others. However, metal and metal oxide nanoparticles lack chemical stability and mechanical strength. They exhibit extremely high pressure drop or head loss in fixed-bed column operation and are not suitable for any flow-through systems. Also, nanoparticles tend to aggregate; this phenomenon reduces their high surface area to volume ratio and subsequently reduces effectiveness. By appropriately dispersing metal and metal oxide nanoparticles into synthetic and naturally occurring polymers, many of the shortcomings can be overcome without compromising the parent properties of the nanoparticles. Furthermore, the appropriate choice of the polymer host with specific functional groups may even lead to the enhancement of the properties of nanoparticles. The synthesis of hybrid materials involves two broad pathways: dispersing the nanoparticles (i) within pre-formed or commercially available polymers; and (ii) during the polymerization process. This review presents a broad coverage of nanoparticles and polymeric/biopolymeric host materials and the resulting properties of the hybrid composites. In addition, the review discusses the role of the Donnan membrane effect exerted by the host functionalized polymer in harnessing the desirable properties of metal and metal oxide nanoparticles for intended applications.

Fused filament 3D printing of ionic polymer-metal composites for soft robotics

Science.gov (United States)

Carrico, James D.; Leang, Kam K.

2017-04-01

Additive manufacturing techniques are used to create three-dimensional structures with complex shapes and features from polymer and/or metal materials. For example, fused filament three-dimensional (3D) printing utilizes non-electroactive polymers, such as acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA), to build structures and components in a layer-by-layer fashion for a wide variety of applications. Presented here is a summary of recent work on a fused filament 3D-printing technique to create 3D ionic polymer-metal composite (IPMC) structures for applications in soft robotics. The 3D printing technique overcomes some of the limitations of existing manufacturing processes for creating IPMCs, such as limited shapes and sizes and time-consuming manufacturing steps. In the process described, first a precursor material (non-acid Nafion precursor resin) is extruded into a thermoplastic filament for 3D printing. Then, a custom-designed 3D printer is described that utilizes the precursor filament to manufacture custom-shaped structures. Finally, the 3D-printed samples are functionalized by hydrolyzing them in an aqueous solution of potassium hydroxide and dimethyl sulfoxide, followed by application of platinum electrodes. Presented are example 3D-printed single and multi-degree-of-freedom IPMC actuators and characterization results, as well as example soft-robotic devices to demonstrate the potential of this process.

Semi-metallic polymers

DEFF Research Database (Denmark)

Bubnova, Olga; Khan, Zia Ullah; Wang, Hui

2014-01-01

Polymers are lightweight, flexible, solution-processable materials that are promising for low-cost printed electronics as well as for mass-produced and large-area applications. Previous studies demonstrated that they can possess insulating, semiconducting or metallic properties; here we report...... that polymers can also be semi-metallic. Semi-metals, exemplified by bismuth, graphite and telluride alloys, have no energy bandgap and a very low density of states at the Fermi level. Furthermore, they typically have a higher Seebeck coefficient and lower thermal conductivities compared with metals, thus being...... a Fermi glass to a semi-metal. The high Seebeck value, the metallic conductivity at room temperature and the absence of unpaired electron spins makes polymer semi-metals attractive for thermoelectrics and spintronics....

Synthesis by plasma of polymer-metal materials; Sintesis por plasma de materiales polimero-metal

Energy Technology Data Exchange (ETDEWEB)

Fernandez R, G

2004-07-01

The objective of this work is the design of an experimental set-up to synthesize polymer- metal composites by plasma with versatility in the conditions of synthesis. The main components are a vacuum system capable to reach up to 10{sup -2} mbar and valves and accessories to control the pressure in the system. In order to generate the electrical discharges and the plasma, an electrical circuit with an inductive connection at 13.56 MHz of frequency was constructed. The electric field partially ionizes the reactor atmosphere where the polymer-metal composites were synthesized. The reactor has two metallic electrodes, one in front of the other, where the particles electrically charged collide against the electrodes producing ablation on them. The polymer-metal composites were synthesized by means of an inductive connection at 13.56 MHz. Aniline, 3-chlorine-ethylene and electrodes of silver (Ag) and copper (Cu) were used in a cylindrical reactor coupled with an external coil to generate glow discharges. The average pressures were 6.15 X 10{sup -1} and 5.2 X 10{sup -1} mbar for the synthesis of Poly aniline (P An) and Poly chloroethylene (PE-CI), respectively. The synthesis was performed during 60 and 180 minutes for P An and PE-CI, respectively. The polymers were formed, as films, with an average thickness of 6.42 {mu}m for P An and, in the case of PE-CI, with an approximately growing rate of 14 {eta}m/W. The power in the syntheses was 30, 50, 70 and 90 W for P An and 50, 100, 120, 140 170, and 200 W for PE-CI. The characterization of the polymer-metal composites was done by energy dispersive spectroscopy to study the composition and the relation of the elements involved in the synthesis. The morphology of the films was studied by means of scanning electron microscopy. The infrared analysis (IR) was done to study the chemicals bonds and the structure of these polymers. Another important study in these materials was the behavior of the electrical conductivity ({sigma

Radiation induced synthesis of conducting polymers and their metal nano-composites

International Nuclear Information System (INIS)

Cui, Zhenpeng

2017-01-01

The aim of the present work is to demonstrate the versatility of the gamma (γ)-rays based radiolytic method and to extend our methodology to the synthesis of various conducting polymers (CPs) in water in different experimental conditions. Poly(3,4-ethylenedioxy-thiophene) (PEDOT) and poly-pyrrole (PPy) conjugated polymers were successfully prepared and characterized in solution and after deposition by complementary spectroscopic and microscopic techniques. Also their thermal stability and their electrical conductivity were studied and compared with those of CPs prepared by conventional methods. The influence of the nature of radiation-induced oxidizing radicals, of the ionic strength, of the medium, of the pH, of the presence of surfactant-based soft templates on the growth mechanism, on the efficiency of polymerization, on the morphology of the obtained CPs as well as on their absorption and conducting properties was checked. Also, the radiolytic method was extend to the synthesis of CPs/noble metal nano-composites. Different preparation methodologies were developed based on two-step method and one-pot method, by using oxidation route or reduction route. Our new radiolytic strategy described and extended in this manuscript opens the way for the preparation of different kinds of CPs and CPs nano-composites not only in aqueous solutions but also in various environments foreshadowing many promising applications.. (author)

Microfluidic Pumps Containing Teflon [Trademark] AF Diaphragms

Science.gov (United States)

Willis, Peter; White, Victor; Grunthaner, Frank; Ikeda, Mike; Mathies, Richard A.

2009-01-01

Microfluidic pumps and valves based on pneumatically actuated diaphragms made of Teflon AF polymers are being developed for incorporation into laboratory-on-a-chip devices that must perform well over temperature ranges wider than those of prior diaphragm-based microfluidic pumps and valves. Other potential applications include implanted biomedical microfluidic devices, wherein the biocompatability of Teflon AF polymers would be highly advantageous. These pumps and valves have been demonstrated to function stably after cycling through temperatures from -125 to 120 C. These pumps and valves are intended to be successors to similar prior pumps and valves containing diaphragms made of polydimethylsiloxane (PDMS) [commonly known as silicone rubber]. The PDMS-containing valves ae designed to function stably only within the temperature range from 5 to 80 C. Undesirably, PDMS membranes are somwehat porous and retain water. PDMS is especially unsuitable for use at temperatures below 0 C because the formation of ice crystals increases porosity and introduces microshear.

Bio-applications of ionic polymer metal composite transducers

Science.gov (United States)

Aw, K. C.; McDaid, A. J.

2014-07-01

Traditional robotic actuators have advanced performance which in some aspects can surpass that of humans, however they are lacking when it comes to developing devices which are capable of operating together with humans. Bio-inspired transducers, for example ionic polymer metal composites (IPMC), which have similar properties to human tissue and muscle, demonstrate much future promise as candidates for replacing traditional robotic actuators in medical robotics applications. This paper outlines four biomedical robotics applications, an IPMC stepper motor, an assistive glove exoskeleton/prosthetic hand, a surgical robotic tool and a micromanipulation system. These applications have been developed using mechanical design/modelling techniques with IPMC ‘artificial muscle’ as the actuation system. The systems are designed by first simulating the performance using an IPMC model and dynamic models of the mechanical system; the appropriate advanced adaptive control schemes are then implemented to ensure that the IPMCs operate in the correct manner, robustly over time. This paper serves as an overview of the applications and concludes with some discussion on the future challenges of developing real-world IPMC applications.

Bio-applications of ionic polymer metal composite transducers

International Nuclear Information System (INIS)

Aw, K C; McDaid, A J

2014-01-01

Traditional robotic actuators have advanced performance which in some aspects can surpass that of humans, however they are lacking when it comes to developing devices which are capable of operating together with humans. Bio-inspired transducers, for example ionic polymer metal composites (IPMC), which have similar properties to human tissue and muscle, demonstrate much future promise as candidates for replacing traditional robotic actuators in medical robotics applications. This paper outlines four biomedical robotics applications, an IPMC stepper motor, an assistive glove exoskeleton/prosthetic hand, a surgical robotic tool and a micromanipulation system. These applications have been developed using mechanical design/modelling techniques with IPMC ‘artificial muscle’ as the actuation system. The systems are designed by first simulating the performance using an IPMC model and dynamic models of the mechanical system; the appropriate advanced adaptive control schemes are then implemented to ensure that the IPMCs operate in the correct manner, robustly over time. This paper serves as an overview of the applications and concludes with some discussion on the future challenges of developing real-world IPMC applications

Design-based modeling of magnetically actuated soft diaphragm materials

Science.gov (United States)

Jayaneththi, V. R.; Aw, K. C.; McDaid, A. J.

2018-04-01

Magnetic polymer composites (MPC) have shown promise for emerging biomedical applications such as lab-on-a-chip and implantable drug delivery. These soft material actuators are capable of fast response, large deformation and wireless actuation. Existing MPC modeling approaches are computationally expensive and unsuitable for rapid design prototyping and real-time control applications. This paper proposes a macro-scale 1-DOF model capable of predicting force and displacement of an MPC diaphragm actuator. Model validation confirmed both blocked force and displacement can be accurately predicted in a variety of working conditions i.e. different magnetic field strengths, static/dynamic fields, and gap distances. The contribution of this work includes a comprehensive experimental investigation of a macro-scale diaphragm actuator; the derivation and validation of a new phenomenological model to describe MPC actuation; and insights into the proposed model’s design-based functionality i.e. scalability and generalizability in terms of magnetic filler concentration and diaphragm diameter. Due to the lumped element modeling approach, the proposed model can also be adapted to alternative actuator configurations, and thus presents a useful tool for design, control and simulation of novel MPC applications.

Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant

OpenAIRE

Petersen, Richard C.

2011-01-01

Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats reve...

Nanothorn electrodes for ionic polymer-metal composite artificial muscles.

Science.gov (United States)

Palmre, Viljar; Pugal, David; Kim, Kwang J; Leang, Kam K; Asaka, Kinji; Aabloo, Alvo

2014-08-22

Ionic polymer-metal composites (IPMCs) have recently received tremendous interest as soft biomimetic actuators and sensors in various bioengineering and human affinity applications, such as artificial muscles and actuators, aquatic propulsors, robotic end-effectors, and active catheters. Main challenges in developing biomimetic actuators are the attainment of high strain and actuation force at low operating voltage. Here we first report a nanostructured electrode surface design for IPMC comprising platinum nanothorn assemblies with multiple sharp tips. The newly developed actuator with the nanostructured electrodes shows a new way to achieve highly enhanced electromechanical performance over existing flat-surfaced electrodes. We demonstrate that the formation and growth of the nanothorn assemblies at the electrode interface lead to a dramatic improvement (3- to 5-fold increase) in both actuation range and blocking force at low driving voltage (1-3 V). These advances are related to the highly capacitive properties of nanothorn assemblies, increasing significantly the charge transport during the actuation process.

Corrosion at the Polymer-Metal Interface in Artificial Seawater Solutions

Directory of Open Access Journals (Sweden)

Amelia M. Anderson-Wile

2012-01-01

Full Text Available Polymer components for liquid sealing applications are employed in a variety of potentially corrosive environments, such as seawater. Frequently, corrosion of the metal is found at or adjacent to the rubber-metal interface rather than at a noncontact area. The corrosion of different metal alloys (titanium, bronze, nickel, aluminum, 316 stainless steel, and 4130 steel in combination with rubber O-rings (Buna-N and EPDM of varying internal diameters and cross-sectional shapes in seawater over a period of four years is described herein. The corrosion of some metals (i.e., 4130 stainless steel was found to be accelerated through interaction with Buna-N rubber O-rings. Theories to account for corrosion at the polymer-metal interface, especially with respect to polymer composition and O-ring size and shape, are discussed.

A resonant force sensor based on ionic polymer metal composites

International Nuclear Information System (INIS)

Bonomo, Claudia; Fortuna, Luigi; Giannone, Pietro; Graziani, Salvatore; Strazzeri, Salvatore

2008-01-01

In this paper a novel force sensor, based on ionic polymer metal composites (IPMCs), is presented. The system has DC sensing capabilities and is able to work in the range of a few millinewtons. IPMCs are emerging materials used to realize motion actuators and sensors. An IPMC strip is activated in a beam fixed/simply-supported configuration. The beam is tightened at the simply-supported end by a force. This influences the natural resonant frequency of the beam; the value of the resonant frequency is used in the proposed system to estimate the force applied in the axial direction. The performance of the system based on the IPMC material has proved to be comparable with that of sensors based on other sensing mechanisms. This suggests the possibility of using this class of polymeric devices to realize PMEMS (plastic micro electrical mechanical systems) sensors

A resonant force sensor based on ionic polymer metal composites

Science.gov (United States)

Bonomo, Claudia; Fortuna, Luigi; Giannone, Pietro; Graziani, Salvatore; Strazzeri, Salvatore

2008-02-01

In this paper a novel force sensor, based on ionic polymer metal composites (IPMCs), is presented. The system has DC sensing capabilities and is able to work in the range of a few millinewtons. IPMCs are emerging materials used to realize motion actuators and sensors. An IPMC strip is activated in a beam fixed/simply-supported configuration. The beam is tightened at the simply-supported end by a force. This influences the natural resonant frequency of the beam; the value of the resonant frequency is used in the proposed system to estimate the force applied in the axial direction. The performance of the system based on the IPMC material has proved to be comparable with that of sensors based on other sensing mechanisms. This suggests the possibility of using this class of polymeric devices to realize PMEMS (plastic micro electrical mechanical systems) sensors.

Modeling of robotic fish propelled by an ionic polymer-metal composite caudal fin

Science.gov (United States)

Chen, Zheng; Shatara, Stephan; Tan, Xiaobo

2009-03-01

In this paper, a model is proposed for a biomimetic robotic fish propelled by an ionic polymer metal composite (IPMC) actuator with a rigid passive fin at the end. The model incorporates both IPMC actuation dynamics and the hydrodynamics, and predicts the steady-state speed of the robot under a periodic actuation voltage. Experimental results have shown that the proposed model can predict the fish motion for different tail dimensions. Since its parameters are expressed in terms of physical properties and geometric dimensions, the model is expected to be instrumental in optimal design of the robotic fish.

High temperature polymer concrete compositions

Science.gov (United States)

Fontana, Jack J.; Reams, Walter

1985-01-01

This invention is concerned with a polymer concrete composition, which is a two-component composition useful with many bases including metal. Component A, the aggregate composition, is broadly composed of silica, silica flour, portland cement, and acrylamide, whereas Component B, which is primarily vinyl and acrylyl reactive monomers, is a liquid system. A preferred formulation emphasizing the major necessary components is as follows: ______________________________________ Component A: Silica sand 60-77 wt. % Silica flour 5-10 wt. % Portland cement 15-25 wt. % Acrylamide 1-5 wt. % Component B: Styrene 50-60 wt. % Trimethylolpropane 35-40 wt. % trimethacrylate ______________________________________ and necessary initiators, accelerators, and surfactants.

Ionic polymer-metal composite enabled robotic manta ray

Science.gov (United States)

Chen, Zheng; Um, Tae I.; Bart-Smith, Hilary

2011-04-01

The manta ray, Manta birostris, demonstrates excellent swimming capabilities; generating highly efficient thrust via flapping of dorsally flattened pectoral fins. In this paper, we present an underwater robot that mimics the swimming behavior of the manta ray. An assembly-based fabrication method is developed to create the artificial pectoral fins, which are capable of generating oscillatory with a large twisting angle between leading and trailing edges. Ionic polymer-metal composite (IPMC) actuators are used as artificial muscles in the fin. Each fin consists of four IPMC beams bonded with a compliant poly(dimethylsiloxane) (PDMS) membrane. By controlling each individual IPMC strips, we are able to generate complex flapping motions. The fin is characterized in terms of tip deflection, tip blocking force, twist angle, and power consumption. Based on the characteristics of the artificial pectoral fin, a small size and free-swimming robotic manta ray is developed. The robot consists of two artificial pectoral fins, a rigid body, and an on-board control unit with a lithium ion rechargeable battery. Experimental results show that the robot swam at a speed of up to 0.055 body length per second (BL/sec).

Experimental Characterization of Ionic Polymer Metal Composite as a Novel Fractional Order Element

Directory of Open Access Journals (Sweden)

Riccardo Caponetto

2013-01-01

Full Text Available Ionic polymer metal composites (IPMCs are electroactive materials made of ionic polymer thin membranes with platinum metallization on their surfaces. They are interesting materials due to not only their electromechanical applications as transducers but also to their electrochemical features and the relationship between the ionic/solvent current and the potential field. Their electrochemical properties thus suggest the possibility for exploiting them as compact fractional-order elements (FOEs with a view of defining fabrication processes and production strategies that assure the desired performances. In this paper, the experimental electrical characterization of a brand new IPMC setup in a fixed sandwich configuration is proposed. Two IPMC devices with different platinum absorption times (5 h and 20 h are characterized through experimental data: first, a preliminary linearity study is performed for a fixed input voltage amplitude in order to determine the frequency region where IPMC can be approximated as linear; then, a frequency analysis is carried out in order to identify a coherent fractional-order dynamics in the bode diagrams. Such analyses take the first steps towards a simplified model of IPMC as a compact electronic FOE for which the fractional exponent value depends on fabrication parameters as the absorption time.

Understanding the origins of metal-organic framework/polymer compatibility.

Science.gov (United States)

Semino, R; Moreton, J C; Ramsahye, N A; Cohen, S M; Maurin, G

2018-01-14

The microscopic interfacial structures for a series of metal-organic framework/polymer composites consisting of the Zr-based UiO-66 coupled with different polymers are systematically explored by applying a computational methodology that integrates density functional theory calculations and force field-based molecular dynamics simulations. These predictions are correlated with experimental findings to unravel the structure-compatibility relationship of the MOF/polymer pairs. The relative contributions of the intermolecular MOF/polymer interactions and the flexibility/rigidity of the polymer with respect to the microscopic structure of the interface are rationalized, and their impact on the compatibility of the two components in the resulting composite is discussed. The most compatible pairs among those investigated involve more flexible polymers, i.e. polyvinylidene fluoride (PVDF) and polyethylene glycol (PEG). These polymers exhibit an enhanced contact surface, due to a better adaptation of their configuration to the MOF surface. In these cases, the irregularities at the MOF surface are filled by the polymer, and even some penetration of the terminal groups of the polymer into the pores of the MOF can be observed. As a result, the affinity between the MOF and the polymer is very high; however, the pores of the MOF may be sterically blocked due to the strong MOF/polymer interactions, as evidenced by UiO-66/PEG composites. In contrast, composites involving polymers that exhibit higher rigidity, such as the polymer of intrinsic microporosity-1 (PIM-1) or polystyrene (PS), present interfacial microvoids that contribute to a decrease in the contact surface between the two components, thus reducing the MOF/polymer affinity.

Method for producing nanowire-polymer composite electrodes

Energy Technology Data Exchange (ETDEWEB)

Pei, Qibing; Yu, Zhibin

2017-11-21

A method for producing flexible, nanoparticle-polymer composite electrodes is described. Conductive nanoparticles, preferably metal nanowires or nanotubes, are deposited on a smooth surface of a platform to produce a porous conductive layer. A second application of conductive nanoparticles or a mixture of nanoparticles can also be deposited to form a porous conductive layer. The conductive layer is then coated with at least one coating of monomers that is polymerized to form a conductive layer-polymer composite film. Optionally, a protective coating can be applied to the top of the composite film. In one embodiment, the monomer coating includes light transducing particles to reduce the total internal reflection of light through the composite film or pigments that absorb light at one wavelength and re-emit light at a longer wavelength. The resulting composite film has an active side that is smooth with surface height variations of 100 nm or less.

Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant

Directory of Open Access Journals (Sweden)

Richard C. Petersen

2011-01-01

Full Text Available Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P<10−4, and 19.3% to 77.7% at 0.1 mm, P<10−8. Carbon-fiber fragments planned to occur in the test designs, instead of producing an inflammation, stimulated bone formation and increased bone integration to the implant. In addition, low-thermal polymer processing allows incorporation of minerals and pharmaceuticals for future major tissue-engineering potential.

Fabrication of polymer micro-lens array with pneumatically diaphragm-driven drop-on-demand inkjet technology.

Science.gov (United States)

Xie, Dan; Zhang, Honghai; Shu, Xiayun; Xiao, Junfeng

2012-07-02

The paper reports an effective method to fabricate micro-lens arrays with the ultraviolet-curable polymer, using an original pneumatically diaphragm-driven drop-on-demand inkjet system. An array of plano convex micro-lenses can be formed on the glass substrate due to surface tension and hydrophobic effect. The micro-lens arrays have uniform focusing function, smooth and real planar surface. The fabrication process showed good repeatability as well, fifty micro-lenses randomly selected form 9 × 9 miro-lens array with an average diameter of 333.28μm showed 1.1% variations. Also, the focal length, the surface roughness and optical property of the fabricated micro-lenses are measured, analyzed and proved satisfactory. The technique shows great potential for fabricating polymer micro-lens arrays with high flexibility, simple technological process and low production cost.

Microgel polymer composite fibres

OpenAIRE

Kehren, Dominic

2014-01-01

In this thesis some novel ideas and advancements in the field of polymer composite fibres, specifically microgel-based polymer composite fibres have been achieved. The main task was to investigate and understand the electrospinning process of microgels and polymers and the interplay of parameter influences, in order to fabricate reproducible and continuously homogenous composite fibres. The main aim was to fabricate a composite material which combines the special properties of polymer fibres ...

Modeling back-relaxation in ionic polymer metal composites: The role of steric effects and composite layers

Science.gov (United States)

Porfiri, Maurizio; Sharghi, Hesam; Zhang, Peng

2018-01-01

Ionic polymer metal composites (IPMCs) are a new class of active materials that are gaining traction as soft actuators in medical and industrial applications. IPMCs can undergo large deformations under modest voltage inputs, in dry and wet environments. Past studies have demonstrated that physical and geometric properties of all the IPMC constituents (ionomer, electrodes, and counterions) may all influence the time scales of the transient response and severity of the back-relaxation. In this study, we present a detailed mathematical model to investigate how the finite size of the counterions and the presence of metal particles in the vicinity of the electrodes modulate IPMC actuation. We build on previous work by our group on thermodynamically consistent modeling of IPMC mechanics and electrochemistry, which attributes IPMC actuation to the interplay between Maxwell stress and osmotic forces. To gain insight into the role of physical and geometric parameters, the resulting nonlinear partial differential equations are solved semianalytically using the method of matched asymptotic expansions, for the initial transient and the steady-state. A numerical solution in COMSOL Multiphysics® is developed to verify semianalytical findings and further explore IPMC actuation. Our model can successfully predict the entire response of IPMCs, from the initial bending toward the anode to the steady-state toward the cathode. We find that the steric effect can abolish the back-relaxation of IPMCs by restraining the counterions' concentration near the electrodes. We also find that increasing the thickness of the ionomer-metal composite layers may enhance IPMC actuation through increased osmotic forces and Maxwell stress.

A biomimetic jellyfish robot based on ionic polymer metal composite actuators

International Nuclear Information System (INIS)

Yeom, Sung-Weon; Oh, Il-Kwon

2009-01-01

A biomimetic jellyfish robot based on ionic polymer metal composite actuators was fabricated and activated to mimic real locomotive behavior with pulse and recovery processes. To imitate the curved shape of the jellyfish, a thermal treatment was applied to obtain a permanent initial deformation of a hemispherical form. The bio-inspired input signal was generated for mimicking real locomotion of the jellyfish. The vertical floating displacement and the thrust force of the biomimetic jellyfish robot under various input signals were measured and compared. The present results show that the bio-inspired electrical input signal with pulse-recovery process generates much higher floating velocity of the biomimetic jellyfish robot in comparison with pure sinusoidal excitations. The curved shape of the IPMC actuator through thermal treatments can be successfully applied to mimic the real biomimetic robots with smooth curves

Structure and properties of nanocrystalline soft magnetic composite materials with silicon polymer matrix

International Nuclear Information System (INIS)

Dobrzanski, L.A.; Nowosielski, R.; Konieczny, J.; PrzybyI, A.; WysIocki, J.

2005-01-01

The paper concerns investigation of nanocrystalline composites technology preparation. The composites in the form of rings with rectangular transverse section, and with polymer matrix and nanocrystalline metallic powders fulfillment were made, for obtaining good ferromagnetic properties. The nanocrystalline ferromagnetic powders were manufactured by high-energy ball milling of metallic glasses strips in an as-quenched state. Generally for investigation, Co matrix alloys with the silicon polymer were used. Magnetic properties in the form of hysteresis loop by rings method were measured. Generally composite cores showed lower soft ferromagnetic properties than winded cores of nanocrystalline strips, but composite cores showed interesting mechanical properties. Furthermore, the structure of strips and powders on properties of composites were investigated

Insight into the Broad Field of Polymer Nanocomposites: From Carbon Nanotubes to Clay Nanoplatelets, via Metal Nanoparticles

Directory of Open Access Journals (Sweden)

Cristina Stefanescu

2009-11-01

Full Text Available Highly ordered polymer nanocomposites are complex materials that display a rich morphological behavior owing to variations in composition, structure, and properties on a nanometer length scale. Metal-polymer nanocomposite materials are becoming more popular for applications requiring low cost, high metal surface areas. Catalytic systems seem to be the most prevalent application for a wide range of metals used in polymer nanocomposites, particularly for metals like Pt, Ni, Co, and Au, with known catalytic activities. On the other hand, among the most frequently utilized techniques to prepare polymer/CNT and/or polymer/clay nanocomposites are approaches like melt mixing, solution casting, electrospinning and solid-state shear pulverization. Additionally, some of the current and potential applications of polymer/CNT and/or polymer/clay nanocomposites include photovoltaic devices, optical switches, electromagnetic interference (EMI shielding, aerospace and automotive materials, packaging, adhesives and coatings. This extensive review covers a broad range of articles, typically from high impact-factor journals, on most of the polymer-nanocomposites known to date: polymer/carbon nanotubes, polymer/metal nanospheres, and polymer/clay nanoplatelets composites. The various types of nanocomposites are described form the preparation stages to performance and applications. Comparisons of the various types of nanocomposites are conducted and conclusions are formulated.

Metal-polymer nanocomposites for functional applications

Energy Technology Data Exchange (ETDEWEB)

Faupel, Franz; Zaporojtchenko, Vladimir; Strunskus, Thomas [Christian-Albrechts-Universitaet zu Kiel (Germany). Institut fuer Materialwissenschaft - Materialverbunde; Elbahri, Mady [Christian-Albrechts-Universitaet zu Kiel (Germany). Institut fuer Materialwissenschaft - Nanochemistry and Engineering

2010-12-15

Nanocomposites combine favorable features of the constituents on the nanoscale to obtain new functionalities. The present paper is concerned with the preparation of polymer-based nanocomposites consisting of metal nanoparticles in a polymer matrix and the resulting functional properties. Emphasis is placed on vapor phase deposition which inter alia allows the incorporation of alloy clusters with well defined composition and tailored filling factor profiles. Examples discussed here include optical composites with tuned particle surface plasmon resonances for plasmonic applications, magnetic high frequency materials with cut-off frequencies well above 1 GHz, sensors that are based on the dramatic change in the electronic properties near the percolation threshold, and antibacterial coatings which benefit from the large effective surface of nanoparticles and the increased chemical potential which both strongly enhance ion release. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

An Ionic-Polymer-Metallic Composite Actuator for Reconfigurable Antennas in Mobile Devices

Directory of Open Access Journals (Sweden)

Yi-Chen Lin

2014-01-01

Full Text Available In this paper, a new application of an electro-active-polymer for a radio frequency (RF switch is presented. We used an ionic polymer metallic composite (IPMC switch to change the operating frequency of an inverted-F antenna. This switch is light in weight, small in volume, and low in cost. In addition, the IPMC is suitable for mobile devices because of its driving voltage of 3 volts and thickness of 200 μm. The IPMC acts as a normally-on switch to control the operating frequency of a reconfigurable antenna in mobile phones. We experimentally demonstrated by network analysis that the IPMC switch could shift its operating frequency from 1.1 to 2.1 GHz, with return losses of than −10 dB at both frequencies. To minimize electrolysis and maximize the operation time in air, propylene carbonate electrolyte with lithium perchlorate (LiClO4 was applied inside the IPMC. The results showed that when the IPMC was actuated over three months at 3.5 V, the tip displacement fell by less than 10%. Therefore, an IPMC actuator is a promising choice for application to a reconfigurable antenna.

Aerogel / Polymer Composite Materials

Science.gov (United States)

Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

2017-01-01

The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

Mechanical Behavior of Polymer Nano Bio Composite for Orthopedic Implants

Science.gov (United States)

Marimuthu, K., Dr.; Rajan, Sankar

2018-04-01

The bio-based polymer composites have been the focus of many scientific and research projects, as well as many commercial programs. In recent years, scientists and engineers have been working together to use the inherent strength and performance of the new class of bio-based composites which is compactable with human body and can act as a substitute for living cells. In this stage the polymer composites also stepped into human bone implants as a replacement for metallic implants which was problems like corrosion resistance and high cost. The polymer composite have the advantage that it can be molded to the required shape, the polymers have high corrosion resistance, less weight and low cost. The aim of this research is to develop and analyze the suitable bio compactable polymer composite for human implants. The nano particles reinforced polymer composites provides good mechanical properties and shows good tribological properties especially in the total hip and knee replacements. The graphene oxide powders are bio compactable and acts as anti biotic. GO nano powder where reinforced into High-density polyethylene in various weight percentage of 0.5% to 2%. The performance of GO nano powder shows better tribological properties. The material produced does not cause any pollution to the environment and at the same time it can be bio compactable and sustainable. The product will act environmentally friendly.

Thermal Shock Resistance of Stabilized Zirconia/Metal Coat on Polymer Matrix Composites by Thermal Spraying Process

Science.gov (United States)

Zhu, Ling; Huang, Wenzhi; Cheng, Haifeng; Cao, Xueqiang

2014-12-01

Stabilized zirconia/metal coating systems were deposited on the polymer matrix composites by a combined thermal spray process. Effects of the thicknesses of metal layers and ceramic layer on thermal shock resistance of the coating systems were investigated. According to the results of thermal shock lifetime, the coating system consisting of 20 μm Zn and 125 μm 8YSZ exhibited the best thermal shock resistance. Based on microstructure evolution, failure modes and failure mechanism of the coating systems were proposed. The main failure modes were the formation of vertical cracks and delamination in the outlayer of substrate, and the appearance of coating spallation. The residual stress, thermal stress and oxidation of substrate near the substrate/metal layer interface were responsible for coating failure, while the oxidation of substrate near the substrate/coating interface was the dominant one.

Tailoring of the morphology and chemical composition of thin organosilane microwave plasma polymer layers on metal substrates

Energy Technology Data Exchange (ETDEWEB)

Grundmeier, G.; Thiemann, P.; Carpentier, J.; Shirtcliffe, N.; Stratmann, M

2004-01-01

The growth of thin microwave organosilicon plasma polymers on model zinc surfaces was investigated as a function of the film thickness and the oxygen partial pressure during film deposition. The evolution of the topology of the film was studied by atomic force microscopy (AFM). The nano- and micro-roughness was investigated at the inner and the outer surfaces of the plasma polymers. A special etching procedure was developed to reveal the underside of the plasma polymer and thereby its inner surface. Rough films contained voids at the interface, which reduced the polymer/metal contact area. The increase in oxygen partial pressure led to a smoother film growth with a perfect imitation of the substrate topography at the interface. The chemical structure of the films was determined by infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). ToF-SIMS at the outer and the inner surface of the plasma polymers showed that the density of methylsilyl groups increases in the outer surface layer of the plasma polymer and depends on the oxygen partial pressure. The chemical composition of the films could be altered to pure SiO{sub 2} without changing the morphology by using oxygen-plasma post-treatment. This was proved by means of IRRAS and AFM. Chemistry and topology of the films were correlated with the apparent water contact angle. It was found that a linear relationship exists between the nanoscopic roughness of the plasma polymer and the static contact angle of water. Superposition of a nanoscopic roughness of the metal surface and the nanoscopic roughness of methylsilyl-rich films led to ultra-hydrophobic films with water contact angles up to 160 deg.

A nonlinear model for ionic polymer metal composites as actuators

Science.gov (United States)

Bonomo, C.; Fortuna, L.; Giannone, P.; Graziani, S.; Strazzeri, S.

2007-02-01

This paper introduces a comprehensive nonlinear dynamic model of motion actuators based on ionic polymer metal composites (IPMCs) working in air. Significant quantities ruling the acting properties of IPMC-based actuators are taken into account. The model is organized as follows. As a first step, the dependence of the IPMC absorbed current on the voltage applied across its thickness is taken into account; a nonlinear circuit model is proposed to describe this relationship. In a second step the transduction of the absorbed current into the IPMC mechanical reaction is modelled. The model resulting from the cascade of both the electrical and the electromechanical stages represents a novel contribution in the field of IPMCs, capable of describing the electromechanical behaviour of these materials and predicting relevant quantities in a large range of applied signals. The effect of actuator scaling is also investigated, giving interesting support to the activities involved in the design of actuating devices based on these novel materials. Evidence of the excellent agreement between the estimations obtained by using the proposed model and experimental signals is given.

Bias-dependent model of the electrical impedance of ionic polymer-metal composites.

Science.gov (United States)

Cha, Youngsu; Porfiri, Maurizio

2013-02-01

In this paper, we analyze the charge dynamics of ionic polymer-metal composites (IPMCs) in response to voltage inputs composed of a large dc bias and a small superimposed time-varying voltage. The IPMC chemoelectrical behavior is described through the modified Poisson-Nernst-Planck framework, in which steric effects are taken into consideration. The physics of charge build-up and mass transfer in the proximity of the high surface electrodes is modeled by schematizing the IPMC as the stacked sequence of five layers, in which the ionomeric membrane is separated from the metal electrodes by two composite layers. The method of matched asymptotic expansions is used to derive a semianalytical solution for the concentration of mobile counterions and the electric potential in the IPMC, which is, in turn, used to establish an equivalent circuit model for the IPMC electrical response. The circuit model consists of the series connection of a resistor and two complex elements, each constituted by the parallel connection of a capacitor and a Warburg impedance. The resistor is associated with ion transport in the ionomeric membrane and is independent of the dc bias. The capacitors and the Warburg impedance idealize charge build-up and mass transfer in the vicinity of the electrodes and their value is controlled by the dc bias. The proposed approach is validated against experimental results on in-house fabricated IPMCs and the accuracy of the equivalent circuit is assessed through comparison with finite element results.

Metal{Polymer Hybrid Materials For Flexible Transparent Conductors

Science.gov (United States)

Narayanan, Sudarshan

The field of organic electronics, till recently a mere research topic, is currently making rapid strides and tremendous progress into entering the mainstream electronics industry with several applications and products such as OLED televisions, curved displays, wearable devices, flexible solar cells, etc. already having been commercialized. A major component in these devices, especially for photovoltaic applications, is a transparent conductor used as one of the electrodes, which in most commercial applications are highly doped wide bandgap semiconducting oxides also called Transparent Conducting Oxides (TCOs). However, TCOs exhibit inherent disadvantages such as limited supply, brittle mechanical properties, expensive processing that present major barriers for the more widespread economic use in applications such as exible transparent conductors, owing to which suitable alternative materials are being sought. In this context we present two approaches in realizing alternative TCs using metal-polymer hybrid materials, with high figures of merit that are easily processable, reasonably inexpensive and mechanically robust as well. In this context, our first approach employs laminated metal-polymer photonic bandgap structures to effectively tune optical and electrical properties by an appropriate design of the material stack, factoring in the effect of the materials involved, the number of layers and layer properties. We have found that in the case of a four-bilayer Au/polystyrene (AujPS) laminate structure, an enhancement in optical transmittance of ˜ 500% in comparison to a monolithic A film of equivalent thickness, can be achieved. The high conductivity (˜ 106 O--1cm--1) of the metallic component, Au in this case, also ensures planar conductivity; metallic inclusions in the dielectric polymer layer can in principle give rise to out-of-plane conductivity as well enabling a fully functional TC. Such materials also have immense potential for several other applications

Ionic Polymer-Metal Composites (IPMCs) as Biomimetic Sensors, Actuators and Artificial Muscles: A Review

Science.gov (United States)

Shahinpoor, M.; Bar-Cohen, Y.; Simpson, J. O.; Smith, J.

1998-01-01

This paper presents an introduction to ionic polymer-metal composites and some mathematical modeling pertaining to them. It further discusses a number of recent findings in connection with ion-exchange polymer-metal composites (IPMCS) as biomimetic sensors and actuators. Strips of these composites can undergo large bending and flapping displacement if an electric field is imposed across their thickness. Thus, in this sense they are large motion actuators. Conversely by bending the composite strip, either quasi-statically or dynamically, a voltage is produced across the thickness of the strip. Thus, they are also large motion sensors. The output voltage can be calibrated for a standard size sensor and correlated to the applied loads or stresses. They can be manufactured and cut in any size and shape. In this paper first the sensing capability of these materials is reported. The preliminary results show the existence of a linear relationship between the output voltage and the imposed displacement for almost all cases. Furthermore, the ability of these IPMCs as large motion actuators and robotic manipulators is presented. Several muscle configurations are constructed to demonstrate the capabilities of these IPMC actuators. This paper further identifies key parameters involving the vibrational and resonance characteristics of sensors and actuators made with IPMCS. When the applied signal frequency varies, so does the displacement up to a critical frequency called the resonant frequency where maximum deformation is observed, beyond which the actuator response is diminished. A data acquisition system was used to measure the parameters involved and record the results in real time basis. Also the load characterizations of the IPMCs were measured and it was shown that these actuators exhibit good force to weight characteristics in the presence of low applied voltages. Finally reported are the cryogenic properties of these muscles for potential utilization in an outer space

High temperature energy harvesters utilizing ALN/3C-SiC composite diaphragms

Science.gov (United States)

Lai, Yun-Ju; Li, Wei-Chang; Felmetsger, Valery V.; Senesky, Debbie G.; Pisano, Albert P.

2014-06-01

Microelectromechanical systems (MEMS) energy harvesting devices aiming at powering wireless sensor systems for structural health monitoring in harsh environments are presented. For harsh environment wireless sensor systems, sensor modules are required to operate at elevated temperatures (> 250°C) with capabilities to resist harsh chemical conditions, thereby the use of battery-based power sources becomes challenging and not economically efficient if considering the required maintenance efforts. To address this issue, energy harvesting technology is proposed to replace batteries and provide a sustainable power source for the sensor systems towards autonomous harsh environment wireless sensor networks. In particular, this work demonstrates a micromachined aluminum nitride/cubic silicon carbide (AlN/3C-SiC) composite diaphragm energy harvester, which enables high temperature energy harvesting from ambient pulsed pressure sources. The fabricated device yields an output power density of 87 μW/cm2 under 1.48-psi pressure pulses at 1 kHz while connected to a 14.6-kΩ load resistor. The effects of pulse profile on output voltage have been studied, showing that the output voltage can be maximized by optimizing the diaphragm resonance frequency based on specific pulse characteristics. In addition, temperature dependence of the diaphragm resonance frequency over the range of 20°C to 600°C has been investigated and the device operation at temperatures as high as 600°C has been verified.

Underwater energy harvesting from a turbine hosting ionic polymer metal composites

International Nuclear Information System (INIS)

Cellini, Filippo; Pounds, Jason; Porfiri, Maurizio; Peterson, Sean D

2014-01-01

In this study, we explore the possibility of energy harvesting from fluid flow through a turbine hosting ionic polymer metal composites (IPMCs). Specifically, IPMC harvesters are embedded in the blades of a small-scale vertical axis water turbine to convert flow kinetics into electrical power via low-frequency flow-induced IPMC deformations. An in-house fabricated Savonius–Darrieus hybrid active turbine with three IPMCs is tested in a laboratory water tunnel to estimate the energy harvesting capabilities of the device as a function of the shunting electrical load. The turbine is shown to harvest a few nanowatt from a mean flow of 0.43 m s −1 for shunting resistances in the range 100–1000 Ω. To establish a first understanding of the energy harvesting device, we propose a quasi-static hydroelastic model for the bending of the IPMCs and we utilize a black-box model to study their electromechanical response. (paper)

Hydrophil diaphragms on the basis of perfluorated copolymers FEP and polyacryl nitrile: Manufacture by radiation- initiated grafting and their use for pervaporation

International Nuclear Information System (INIS)

Scholz, H.

1986-01-01

The radiation-initiated grafting copolymerisation of hydrophil monomers to FEP, a copolymer of tetrafluorethene and hexafluorpropene and to polyacryl nitrile (PAN) was examined in this dissertation. The grafted products were used as diaphragms for the separation of water-ethanol mixtures by pervaporation. Water was separated through the diaphragm from the mixture in the pervaporation experiments. It was shown how the mechanical properties of the basic polymer affect the interaction between basic polymer and grafted polymer and how the grafting conditions affect the diaphragm properties. By grafting acrylic acid on to the basic polymers FEP and PAN, very good results were achieved for the water-ethanol separation, if the diaphragms were used in the K form. The selectivity of PAN-g-acrylic acid-K for water reached values of α > 1000. (orig./RB) [de

Radiation crosslinking of polymers with segregated metallic particles. Final report, June 1, 1971--September 30, 1973

International Nuclear Information System (INIS)

Corneliussen, R.D.; Kamel, I.; Kusy, R.P.

1973-01-01

Through the past four years of research, a new approach to fabricating conductive polymer/metal composites has been developed. This approach consists of compacting mixtures of polymer and metal powders and then stabilizing the composite through radiation-induced crosslinking. The result is a mechanically strong, conductive materials consisting of two intertwining networks. One is a massive network consisting of fused crosslinked, large (greater than 100 μ) polymer particles while the other is a fine network of small, metallic particles (greater than 10 μ). Nine different systems including crystalline, amorphous, and rubbery polymers were studied. Processing at this time is limited to compression molding in a closed die because of network stability problems. Costs for processing were estimated at about $6.00/lb compared to $50.00 and up for commercial material based on random networks. (U.S.)

Polymer/metal nanocomposites for biomedical applications.

Science.gov (United States)

Zare, Yasser; Shabani, Iman

2016-03-01

Polymer/metal nanocomposites consisting of polymer as matrix and metal nanoparticles as nanofiller commonly show several attractive advantages such as electrical, mechanical and optical characteristics. Accordingly, many scientific and industrial communities have focused on polymer/metal nanocomposites in order to develop some new products or substitute the available materials. In the current paper, characteristics and applications of polymer/metal nanocomposites for biomedical applications are extensively explained in several categories including strong and stable materials, conductive devices, sensors and biomedical products. Moreover, some perspective utilizations are suggested for future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Influence of double-diaphragm vacuum compaction on deformation during forming of composite prepregs

Directory of Open Access Journals (Sweden)

Hassan Alshahrani

2016-12-01

Full Text Available During the diaphragm forming process, a vacuum seal is applied between the upper and lower diaphragms to compact and hold the laminate. Therefore, a thorough characterization of the in-plane shear behavior of fabrics under diaphragm forming conditions must take into account the effect of vacuum-sealing and compaction between the two diaphragms during bias extension. The study presented here examined the shear angles of out-of-autoclave 8-harness satin woven carbon/epoxy prepregs under diaphragm compaction. A bias extension test was conducted to study the effect of diaphragm compaction and ply interactions on shear properties. The test was performed at different compaction levels, and changes in shear angle with respect to vacuum levels and diaphragm compaction forces were observed. The contribution of diaphragm material and ply interaction to shear stiffness was evaluated and compared with results from a direct bias extension test. The samples were tested at both room temperature and at elevated temperatures using a radiant heater. The results show that shear angle decreases significantly as vacuum pressure and compaction is applied between the two diaphragms. This finding indicates that vacuum levels and compaction forces have a significant influence on the deformation limit and wrinkling onset during the diaphragm forming process.

Radioisotope albedo method for measuring thickness of polymers coatings on metal basis

International Nuclear Information System (INIS)

Kapranov, B.I.; Myakin'kova, L.V.; Shaverin, V.A.

1986-01-01

Theoretical analysis of albedo thickness measuring of polymer coating-metal composite has been made and experimental studies of the range of tested thicknesses of polymer coating when different metal bases and radiation sources are used have been conducted. It is shown that the thickness of polymer coating on metal can be measured using backscattered γ-radiation in the energy range of 20-120 keV at the error 0.15-0.8 mm, at that, for thickness up to 23 mm the use of 147 Pm isotope can be defined as the optimum one; for thicknesses up to 40 mm 241 Am should be used; at thicknesses up to 60 mm - 57 Co. The AGAT-1 albedo gamma thickness gage, designed for measuring thickness of fiber glass coating up to 20 mm on metal base, is described

Inorganic Metal Oxide/Organic Polymer Nanocomposites And Method Thereof

Science.gov (United States)

Gash, Alexander E.; Satcher, Joe H.; Simpson, Randy

2004-11-16

A synthetic method for preparation of hybrid inorganic/organic energetic nanocomposites is disclosed herein. The method employs the use of stable metal in organic salts and organic solvents as well as an organic polymer with good solubility in the solvent system to produce novel nanocomposite energetic materials. In addition, fuel metal powders (particularly those that are oxophilic) can be incorporated into composition. This material has been characterized by thermal methods, energy-filtered transmission electron microscopy (EFTEM), N.sub.2 adsoprtion/desorption methods, and Fourier-Transform (FT-IR) spectroscopy. According to these characterization methods the organic polymer phase fills the nanopores of the material, providing superb mixing of the component phases in the energetic nanocomposite.

A review on robotic fish enabled by ionic polymer-metal composite artificial muscles.

Science.gov (United States)

Chen, Zheng

2017-01-01

A novel actuating material, which is lightweight, soft, and capable of generating large flapping motion under electrical stimuli, is highly desirable to build energy-efficient and maneuverable bio-inspired underwater robots. Ionic polymer-metal composites are important category of electroactive polymers, since they can generate large bending motions under low actuation voltages. IPMCs are ideal artificial muscles for small-scale and bio-inspired robots. This paper takes a system perspective to review the recent work on IPMC-enabled underwater robots, from modeling, fabrication, and bio-inspired design perspectives. First, a physics-based and control-oriented model of IPMC actuator will be reviewed. Second, a bio-inspired robotic fish propelled by IPMC caudal fin will be presented and a steady-state speed model of the fish will be demonstrated. Third, a novel fabrication process for 3D actuating membrane will be introduced and a bio-inspired robotic manta ray propelled by two IPMC pectoral fins will be demonstrated. Fourth, a 2D maneuverable robotic fish propelled by multiple IPMC fin will be presented. Last, advantages and challenges of using IPMC artificial muscles in bio-inspired robots will be concluded.

Synthesis of Thin Film Composite Metal-Organic Frameworks Membranes on Polymer Supports

KAUST Repository

Barankova, Eva

2017-06-01

Since the discovery of size-selective metal-organic frameworks (MOF) researchers have tried to manufacture them into gas separation membranes. ZIF-8 became the most studied MOF for membrane applications mainly because of its simple synthesis, good chemical and thermal stability, recent commercial availability and attractive pore size. The aim of this work is to develop convenient methods for growing ZIF thin layers on polymer supports to obtain defect-free ZIF membranes with good gas separation properties. We present new approaches for ZIF membranes preparation on polymers. We introduce zinc oxide nanoparticles in the support as a secondary metal source for ZIF-8 growth. Initially the ZnO particles were incorporated into the polymer matrix and later on the surface of the polymer by magnetron sputtering. In both cases, the ZnO facilitated to create more nucleation opportunities and improved the ZIF-8 growth compared to the synthesis without using ZnO. By employing the secondary seeded growth method, we were able to obtain thin (900 nm) ZIF-8 layer with good gas separation performance. Next, we propose a metal-chelating polymer as a suitable support for growing ZIF layers. Defect-free ZIF-8 films with a thickness of 600 nm could be obtained by a contra-diffusion method. ZIF-8 membranes were tested for permeation of hydrogen and hydrocarbons, and one of the highest selectivities reported so far for hydrogen/propane, and propylene/propane was obtained. Another promising method to facilitate the growth of MOFs on polymeric supports is the chemical functionalization of the support surface with functional groups, which can complex metal ions and which can covalently bond the MOF crystals. We functionalized the surface of a common porous polymeric membrane with amine groups, which took part in the reaction to form ZIF-8 nanocrystals. We observed an enhancement in adhesion between the ZIF layer and the support. The effect of parameters of the contra-diffusion experiment

21 CFR 888.3560 - Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellofemorotibial polymer/metal... Devices § 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis. (a) Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained...

Ionic polymer-metal composite torsional sensor: physics-based modeling and experimental validation

Science.gov (United States)

Aidi Sharif, Montassar; Lei, Hong; Khalid Al-Rubaiai, Mohammed; Tan, Xiaobo

2018-07-01

Ionic polymer-metal composites (IPMCs) have intrinsic sensing and actuation properties. Typical IPMC sensors are in the shape of beams and only respond to stimuli acting along beam-bending directions. Rod or tube-shaped IPMCs have been explored as omnidirectional bending actuators or sensors. In this paper, physics-based modeling is studied for a tubular IPMC sensor under pure torsional stimulus. The Poisson–Nernst–Planck model is used to describe the fundamental physics within the IPMC, where it is hypothesized that the anion concentration is coupled to the sum of shear strains induced by the torsional stimulus. Finite element simulation is conducted to solve for the torsional sensing response, where some of the key parameters are identified based on experimental measurements using an artificial neural network. Additional experimental results suggest that the proposed model is able to capture the torsional sensing dynamics for different amplitudes and rates of the torsional stimulus.

21 CFR 888.3550 - Knee joint patellofemorotibial polymer/metal/metal constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellofemorotibial polymer/metal/metal... § 888.3550 Knee joint patellofemorotibial polymer/metal/metal constrained cemented prosthesis. (a) Identification. A knee joint patellofemorotibial polymer/metal/metal constrained cemented prosthesis is a device...

Reaction factors for photo-electrochemical deposition of metal silver on polypyrrole as conducting polymer

International Nuclear Information System (INIS)

Kawakita, Jin; Boter, Jelmer M.; Shova, Neupane; Fujihira, Hiroshi; Chikyow, Toyohiro

2015-01-01

Composite of metal and conducting polymer is expected for electrical application by the use of their advantages. For improvement of the composite’s characteristics, it is important to control formation rate and structure of the composites obtained by simultaneous metal deposition and polymerization under photo irradiation. The purpose of this research was to reveal the effects of UV irradiation and dopant type for conducting polymer on photo-electrochemical deposition of metal. Cathodic polarization curves for silver deposition on polypyrrole doped with different types of anion at different intensity of the UV light were compared. Deposited particles were evaluated by the statistical analysis. The experimental results showed that silver deposition on polypyrrole was enhanced by UV introduction and depended on the dopant type.

Asphaltenes-based polymer nano-composites

Science.gov (United States)

Bowen, III, Daniel E

2013-12-17

Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer or ceramic/polymer... Devices § 888.3410 Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained resurfacing...

Correlation of morphology and barrier properties of thin microwave plasma polymer films on metal substrate

International Nuclear Information System (INIS)

Barranco, V.; Carpentier, J.; Grundmeier, G.

2004-01-01

The barrier properties of thin model organosilicon plasma polymers layers on iron are characterised by means of electrochemical impedance spectroscopy (EIS). Tailored thin plasma polymers of controlled morphology and chemical composition were deposited from a microwave discharge. By the analysis of the obtained impedance diagrams, the evolution of the water uptake φ, coating resistance and polymer capacitance with immersion time were monitored and the diffusion coefficients of the water through the films were calculated. The impedance data correlated well with the chemical structure and morphology of the plasma polymer films with a thickness of less than 100 nm. The composition of the films were determined by means of infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The morphology of the plasma polymer surface and the interface between the plasma polymer and the metal were characterised using atomic force microscopy (AFM). It could be shown that, at higher pressure, the film roughness increases which is probably due to the adsorption of plasma polymer nanoparticles formed in the plasma bulk and the faster film growth. This leads to voids with a size of a few tens of nanometers at the polymer/metal interface. The film roughness increases from the interface to the outer surface of the film. By lowering the pressure and thereby slowing the deposition rate, the plasma polymers perfectly imitate the substrate topography and lead to an excellent blocking of the metal surface. Moreover, the ratio of siloxane bonds to methyl-silyl groups increases which implies that the crosslink density is higher at lower deposition rate. The EIS data consistently showed higher coating resistance as well as lower interfacial capacitance values and a better stability over time for the film deposited at slower pressure. The diffusion coefficient of water in thin and ultra-thin plasma

A multiple-shape memory polymer-metal composite actuator capable of programmable control, creating complex 3D motion of bending, twisting, and oscillation

Science.gov (United States)

Shen, Qi; Trabia, Sarah; Stalbaum, Tyler; Palmre, Viljar; Kim, Kwang; Oh, Il-Kwon

2016-04-01

Development of biomimetic actuators has been an essential motivation in the study of smart materials. However, few materials are capable of controlling complex twisting and bending deformations simultaneously or separately using a dynamic control system. Here, we report an ionic polymer-metal composite actuator having multiple-shape memory effect, and is able to perform complex motion by two external inputs, electrical and thermal. Prior to the development of this type of actuator, this capability only could be realized with existing actuator technologies by using multiple actuators or another robotic system. This paper introduces a soft multiple-shape-memory polymer-metal composite (MSMPMC) actuator having multiple degrees-of-freedom that demonstrates high maneuverability when controlled by two external inputs, electrical and thermal. These multiple inputs allow for complex motions that are routine in nature, but that would be otherwise difficult to obtain with a single actuator. To the best of the authors’ knowledge, this MSMPMC actuator is the first solitary actuator capable of multiple-input control and the resulting deformability and maneuverability.

A multiple-shape memory polymer-metal composite actuator capable of programmable control, creating complex 3D motion of bending, twisting, and oscillation.

Science.gov (United States)

Shen, Qi; Trabia, Sarah; Stalbaum, Tyler; Palmre, Viljar; Kim, Kwang; Oh, Il-Kwon

2016-04-15

Development of biomimetic actuators has been an essential motivation in the study of smart materials. However, few materials are capable of controlling complex twisting and bending deformations simultaneously or separately using a dynamic control system. Here, we report an ionic polymer-metal composite actuator having multiple-shape memory effect, and is able to perform complex motion by two external inputs, electrical and thermal. Prior to the development of this type of actuator, this capability only could be realized with existing actuator technologies by using multiple actuators or another robotic system. This paper introduces a soft multiple-shape-memory polymer-metal composite (MSMPMC) actuator having multiple degrees-of-freedom that demonstrates high maneuverability when controlled by two external inputs, electrical and thermal. These multiple inputs allow for complex motions that are routine in nature, but that would be otherwise difficult to obtain with a single actuator. To the best of the authors' knowledge, this MSMPMC actuator is the first solitary actuator capable of multiple-input control and the resulting deformability and maneuverability.

Deformation of extreme viscoelastic metals and composites

International Nuclear Information System (INIS)

Wang, Y.C.; Ludwigson, M.; Lakes, R.S.

2004-01-01

The figure of merit for structural damping and damping layer applications is the product of stiffness E and damping tan δ. For most materials, even practical polymer damping layers, E tan δ is less than 0.6 GPa. We consider several methods to achieve high values of this figure of merit: high damping metals, metal matrix composites and composites containing constituents of negative stiffness. As for high damping metals, damping of polycrystalline zinc was determined and compared with InSn studied earlier. Damping of Zn is less dependent on frequency than that of InSn, so Zn is superior at high frequency. High damping and large stiffness anomalies are possible in viscoelastic composites with inclusions of negative stiffness. Negative stiffness entails a reversal of the usual directional relationship between force and displacement in deformed objects. An isolated object with negative stiffness is unstable, but an inclusion embedded in a composite matrix can be stabilized under some circumstances. Ferroelastic domains in the vicinity of a phase transition can exhibit a region of negative stiffness. Metal matrix composites containing vanadium dioxide were prepared and studied. The concentration of embedded particles was sensitive to the processing method

Wear of polymers and composites

CERN Document Server

Abdelbary, Ahmed

2015-01-01

In the field of tribology, the wear behaviour of polymers and composite materials is considered a highly non-linear phenomenon. Wear of Polymers and Composites introduces fundamentals of polymers and composites tribology. The book suggests a new approach to explore the effect of applied load and surface defects on the fatigue wear behaviour of polymers, using a new tribometer and thorough experiments. It discusses effects of surface cracks, under different static and cyclic loading parameters on wear, and presents an intelligent algorithm, in the form of a neural network, to map the relations

Modulation of the sound press level by the treatment of polymer diaphragms through ion implantation method

International Nuclear Information System (INIS)

Yeo, Sunmog; Park, Jaewon; Lee, Hojae

2010-01-01

We present two different surface modification treatments, an ion implantation, and an ion beam mixing, and show that the surface modifications caused by these treatments are useful tools to modulate the sound press level. The ion implantations on various polymer diaphragms cause an increase in the resonant frequency so that the sound press level is lowered at low frequencies. On the contrary, a Cu or Fe 2 O 3 coating by using an ion beam mixing method causes a decrease in the resonant frequency, resulting in a high sound press level at low frequencies. We discuss the physical reasons for the change in the sound press level due to the ion-implantation methods.

Analytical model for an electrostatically actuated miniature diaphragm compressor

International Nuclear Information System (INIS)

Sathe, Abhijit A; Groll, Eckhard A; Garimella, Suresh V

2008-01-01

This paper presents a new analytical approach for quasi-static modeling of an electrostatically actuated diaphragm compressor that could be employed in a miniature scale refrigeration system. The compressor consists of a flexible circular diaphragm clamped at its circumference. A conformal chamber encloses the diaphragm completely. The membrane and the chamber surfaces are coated with metallic electrodes. A potential difference applied between the diaphragm and the chamber pulls the diaphragm toward the chamber surface progressively from the outer circumference toward the center. This zipping actuation reduces the volume available to the refrigerant gas, thereby increasing its pressure. A segmentation technique is proposed for analysis of the compressor by which the domain is divided into multiple segments for each of which the forces acting on the diaphragm are estimated. The pull-down voltage to completely zip each individual segment is thus obtained. The required voltage for obtaining a specific pressure rise in the chamber can thus be determined. Predictions from the model compare well with other simulation results from the literature, as well as to experimental measurements of the diaphragm displacement and chamber pressure rise in a custom-built setup

Chemistry of the metal-polymer interfacial region.

Science.gov (United States)

Leidheiser, H; Deck, P D

1988-09-02

In many polymer-metal systems, chemical bonds are formed that involve metal-oxygen-carbon complexes. Infrared and Mössbauer spectroscopic studies indicate that carboxylate groups play an important role in some systems. The oxygen sources may be the polymer, the oxygen present in the oxide on the metal surface, or atmospheric oxygen. Diffusion of metal ions from the substrate into the polymer interphase may occur in some systems that are cured at elevated temperatures. It is unclear whether a similar, less extensive diffusion occurs over long time periods in systems maintained at room temperature. The interfacial region is dynamic, and chemical changes occur with aging at room temperature. Positron annihilation spectroscopy may have application to characterizing the voids at the metal-polymer interface.

Selective metal-vapor deposition on solvent evaporated polymer surfaces

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Koji; Tsujioka, Tsuyoshi, E-mail: tsujioka@cc.osaka-kyoiku.ac.jp

2015-12-31

We report a selective metal-vapor deposition phenomenon based on solvent printing and evaporation on polymer surfaces and propose a method to prepare fine metal patterns using maskless vacuum deposition. Evaporation of the solvent molecules from the surface caused large free volumes between surface polymer chains and resulted in high mobility of the chains, enhancing metal-vapor atom desorption from the surface. This phenomenon was applied to prepare metal patterns on the polymer surface using solvent printing and maskless metal vacuum deposition. Metal patterns with high resolution of micron scale were obtained for various metal species and semiconductor polymer substrates including poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and poly(3-hexylthiophene-2,5-diyl). - Highlights: • Selective metal-vapor deposition using solvent evaporation on polymer was attained. • Metal patterns with high resolution were obtained for various metal species. • This method can be applied to achieve fine metal-electrodes for polymer electronics.

Synthesis, characterization and applications of polymer-metal ...

Indian Academy of Sciences (India)

Abstract. 4-Acryloxy acetophenone was prepared and subjected to suspension polymerization with divinyl- benzene as a cross-linking agent. The resulting network polymer was ligated with benzoyl hydrazone. The functional polymer was treated with metal ions [Cu(II), Fe(II)]. The polymer-metal complexes obtained.

A study of water electrolysis using ionic polymer-metal composite for solar energy storage

Science.gov (United States)

Keow, Alicia; Chen, Zheng

2017-04-01

Hydrogen gas can be harvested via the electrolysis of water. The gas is then fed into a proton exchange membrane fuel cell (PEMFC) to produce electricity with clean emission. Ionic polymer-metal composite (IPMC), which is made from electroplating a proton-conductive polymer film called Nafion encourages ion migration and dissociation of water under application of external voltage. This property has been proven to be able to act as catalyst for the electrolysis of pure water. This renewable energy system is inspired by photosynthesis. By using solar panels to gather sunlight as the source of energy, the generation of electricity required to activate the IPMC electrolyser is acquired. The hydrogen gas is collected as storable fuel and can be converted back into energy using a commercial fuel cell. The goal of this research is to create a round-trip energy efficient system which can harvest solar energy, store them in the form of hydrogen gas and convert the stored hydrogen back to electricity through the use of fuel cell with minimal overall losses. The effect of increasing the surface area of contact is explored through etching of the polymer electrolyte membrane (PEM) with argon plasma or manually sanding the surface and how it affects the increase of energy conversion efficiency of the electrolyser. In addition, the relationship between temperature and the IPMC is studied. Experimental results demonstrated that increases in temperature of water and changes in surface area contact correlate with gas generation.

A possible recycling method for high grade steels EAFD in polymer composites.

Science.gov (United States)

Niubó, M; Fernández, A I; Chimenos, J M; Haurie, L

2009-11-15

This work evaluates the feasibility of incorporating electric arc furnace dust (EAFD), as filler in a polymer matrix, to obtain a moldable heavyweight sheet, useful for acoustic insulation in automotive industry. For this purpose EAFD from a steel factory that manufactures high quality steels, was characterized and different formulations of composites were prepared. Physical and mechanical properties, as well as fire behaviour were tested and compared with a polymer composite compounded with common mineral fillers. Optimum formulation with 25% EAFD fulfils the RoHs Directive used by automotive industry to regulate heavy metals content. Leaching test was also performed on prepared composites to classify the material after use.

Nanoporous Polymer-Ceramic Composite Electrolytes for Lithium Metal Batteries

KAUST Repository

Tu, Zhengyuan; Kambe, Yu; Lu, Yingying; Archer, Lynden A.

2013-01-01

A nanoporous composite material that offers the unique combination of high room-temperature ionic conductivity and high mechanical modulus is reported. When used as the separator/electrolyte in lithium batteries employing metallic lithium as anode

Multilayer Electroactive Polymer Composite Material

Science.gov (United States)

Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Park, Cheol (Inventor); Draughon, Gregory K. (Inventor); Ounaies, Zoubeida (Inventor)

2011-01-01

An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

Searching for a new ionomer for 3D printable ionic polymer-metal composites: Aquivion as a candidate

Science.gov (United States)

Trabia, Sarah; Olsen, Zakai; Kim, Kwang J.

2017-11-01

The work presented in this paper introduces Aquivion as a potential candidate for additive manufacturing of ionomeric polymers for the application of IPMCs. First, Aquivion was characterized and compared with Nafion to show that it has the similar qualities, with the major difference being the ionic conductivity. Ionic polymer-metal composites (IPMCs) were fabricated using off-the-shelf membranes of Nafion and Aquivion. The actuation tests showed improved performance for an IPMC with Aquivion as the base compared to an IPMC with a Nafion base. With these results in mind, additive manufacturing of unique shapes using Aquivion filament was studied. A 3D printer was modified to work with Aquivion filament and the polymer was printed into various shapes. Using the printed membranes, IPMCs were fabricated using an electroless plating process. Nafion-based and printed Aquivion-based IPMCs were tested for their performance in back relaxation, frequency driven actuation, blocking force, and mechano-electric sensing. The printed Aquivion-based IPMCs performed comparably to Nafion-based IPMC in back relaxation and showed significantly improved performance in frequency driven actuation, blocking force generation, and mechano-electric sensing.

Dynamic model of ion and water transport in ionic polymer-metal composites

Directory of Open Access Journals (Sweden)

Zicai Zhu

2011-12-01

Full Text Available In the process of electro-mechanical transduction of ionic polymer-metal composites (IPMCs, the transport of ion and water molecule plays an important role. In this paper, the theoretical transport models of IPMCs are critically reviewed, with particular emphasis on the recent developments in the latest decade. The models can be divided into three classes, thermodynamics of irreversible process model, frictional model and Nernst-Planck (NP equation model. To some extent the three models can be transformed into each other, but their differences are also obvious arising from the various mechanisms that considered in different models. The transport of ion and water molecule in IPMCs is compared with that in membrane electrode assembly and electrodialysis membrane to identify and clarify the fundamental transport mechanisms in IPMCs. And an improved transport model is proposed and simplified for numerical analysis. The model considers the convection effect rather than the diffusion as the major transport mechanism, and both the self-diffusion and the electroosmosis drag are accounted for in the water flux equation.

Numerical investigation on vibration characteristics of a micro-speaker diaphragm considering thermoforming effects

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyeong Min; Park, Ke Un [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

2013-10-15

Micro-speaker diaphragms play an important role in generating desired sound responses, and are designed to have thin membrane shapes for flexibility in the axial direction. The micro-speaker diaphragms are formed from thin polymer film through the thermoforming process, in which local thickness reductions occur due to strain localization. This thickness reduction results in a change in vibration characteristics of the diaphragm and different sound responses from that of the original design. In this study, the effect of this thickness change in the diaphragm on its vibration characteristics is numerically investigated by coupling thermoforming simulation, structural analysis and modal analysis. Thus, the thickness change in the diaphragm is calculated from the thermoforming simulation, and reflected in the further structural and modal analyses in order to estimate the relevant stiffness and vibration modes. Comparing these simulation results with those from a diaphragm with the uniform thickness, it is found that a local thickness reduction results in the stiffness reduction and the relevant change in the natural frequencies and the corresponding vibration modes.

Numerical investigation on vibration characteristics of a micro-speaker diaphragm considering thermoforming effects

International Nuclear Information System (INIS)

Kim, Kyeong Min; Park, Ke Un

2013-01-01

Micro-speaker diaphragms play an important role in generating desired sound responses, and are designed to have thin membrane shapes for flexibility in the axial direction. The micro-speaker diaphragms are formed from thin polymer film through the thermoforming process, in which local thickness reductions occur due to strain localization. This thickness reduction results in a change in vibration characteristics of the diaphragm and different sound responses from that of the original design. In this study, the effect of this thickness change in the diaphragm on its vibration characteristics is numerically investigated by coupling thermoforming simulation, structural analysis and modal analysis. Thus, the thickness change in the diaphragm is calculated from the thermoforming simulation, and reflected in the further structural and modal analyses in order to estimate the relevant stiffness and vibration modes. Comparing these simulation results with those from a diaphragm with the uniform thickness, it is found that a local thickness reduction results in the stiffness reduction and the relevant change in the natural frequencies and the corresponding vibration modes.

Polymer filtration: A new technology for selective metals recovery

Energy Technology Data Exchange (ETDEWEB)

Smith, B.F.; Robison, T.W.; Cournoyer, M.E.; Wilson, K.V.; Sauer, N.N.; Mullen, K.I.; Lu, M.T.; Jarvinen, J.J.

1995-04-01

Polymer Filtration (PF) was evaluated for the recovery of electroplating metal ions (zinc and nickel) from rinse waters. Polymer Filtration combines the use of water-soluble metal-binding polymers and ultrafiltration to concentrate metal ions from dilute rinse water solutions. The metal ions are retained by the polymers; the smaller, unbound species freely pass through the ultrafiltration membrane. By using this process the ultrafiltered permeate more than meets EPA discharge limits. The metal ions are recovered from the concentrated polymer solution by pH adjustment using diafiltration and can be recycled to the original electroplating baths with no deleterious effects on the test panels. Metal-ion recovery is accomplished without producing sludge.

21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer/metal semi-constrained... Devices § 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis. (a) Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a device...

One pot electrochemical synthesis of polymer/CNT/metal nanoparticles for fuel cell applications

Science.gov (United States)

Ventrapragada, Lakshman; Zhu, Jingyi; Karakaya, Mehmet; Podila, Ramakrishna; Rao, Apparao; Clemson Nanomaterials center Team

Carbon nanotubes (CNTs) have become a key player in the design of materials for energy applications. They gained their popularity in industrial and scientific research due to their unique properties like excellent conductivity, high surface area, etc. Here we used chemical vapor deposition (CVD) to synthesize two types of CNTs namely, helically coiled CNTs and vertically aligned CNTs. These CNTs were subsequently used to make composites with conducting polymers and metal nanoparticles. One pot electrochemical synthesis was designed to electropolymerize aniline, pyrrole etc. on the surface of the electrode with simultaneous deposition of platinum and gold metal nanoparticles, and CNTs in the polymer matrix. The as synthesized composite materials were characterized with scanning electron microscope for surface morphology and spectroscopic techniques like Raman, UV-Vis for functionality. These were used to study electrocatalytic oxidation of methanol and ethanol for alkaline fuel cell applications. Electrodes fabricated from these composites not only showed good kinetics but also exhibited excellent stability. Uniqueness of this composite lies in its simple two step synthesis and it doesn't involve any surfactants unlike conventional chemical synthesis routes.

Fabrication of carbon-polymer composite bipolar plates for polymer electrolyte membrane fuel cells by compression moulding

International Nuclear Information System (INIS)

Raza, M.A.; Ahmed, R.; Saleem, A.; Din, R.U.

2009-01-01

Fuel cells are considered as one of the most important technologies to address the future energy and environmental pollution problems. These are the most promising power sources for road transportation and portable devices. A fuel cell is an electrochemical device that converts chemical energy into electrical energy. A fuel cell stack consists of bipolar plates and membrane electrode assemblies (MEA). The bipolar plate is by weight, volume and cost one of the most significant components of a fuel cell stack. Major functions of bipolar plates are to separate oxidant and fuel gas, provide flow channels, conduct electricity and provide heat transfer. Bipolar plates can be made from various materials including graphite, metals, carbon / carbon and carbon/ polymer composites. Materials for carbon-polymer composites are relatively inexpensive, less corrosive, strong and channels can be formed by means of a moulding process. Carbon-polymer composites are of two type i.e; thermosetting and thermoplastic. For thermosetting composite a bulk molding compound (BMC) was prepared by adding graphite, vinyl ester resin, methyl ethyl ketone peroxide and cobalt naphthalate. The BMC was thoroughly mixed, poured into a die mould of a bipolar plate with channels and hot pressed at a specific temperature and pressure. A bipolar plate was formed according to the die mould. Design of the mould is also discussed. Conducting polymers were also added to BMC to increase the conductivity of bipolar plates. Particle size of the graphite has also a significant effect on the conductivity of the bipolar plates. Thermoplastic composites were also prepared using polypropylene and graphite.

CFD analysis of a diaphragm free-piston Stirling cryocooler

Science.gov (United States)

Caughley, Alan; Sellier, Mathieu; Gschwendtner, Michael; Tucker, Alan

2016-10-01

This paper presents a Computational Fluid Dynamics (CFD) analysis of a novel free-piston Stirling cryocooler that uses a pair of metal diaphragms to seal and suspend the displacer. The diaphragms allow the displacer to move without rubbing or moving seals. When coupled to a metal diaphragm pressure wave generator, the system produces a complete Stirling cryocooler with no rubbing parts in the working gas space. Initial modelling of this concept using the Sage modelling tool indicated the potential for a useful cryocooler. A proof-of-concept prototype was constructed and achieved cryogenic temperatures. A second prototype was designed and constructed using the experience gained from the first. The prototype produced 29 W of cooling at 77 K and reached a no-load temperature of 56 K. The diaphragm's large diameter and short stroke produces a significant radial component to the oscillating flow fields inside the cryocooler which were not modelled in the one-dimensional analysis tool Sage that was used to design the prototypes. Compared with standard pistons, the diaphragm geometry increases the gas-to-wall heat transfer due to the higher velocities and smaller hydraulic diameters. A Computational Fluid Dynamics (CFD) model of the cryocooler was constructed to understand the underlying fluid-dynamics and heat transfer mechanisms with the aim of further improving performance. The CFD modelling of the heat transfer in the radial flow fields created by the diaphragms shows the possibility of utilizing the flat geometry for heat transfer, reducing the need for, and the size of, expensive heat exchangers. This paper presents details of a CFD analysis used to model the flow and gas-to-wall heat transfer inside the second prototype cryocooler, including experimental validation of the CFD to produce a robust analysis.

Multifunctional Metal/Polymer Composite Fiber for Space Applications, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In this Small Business Innovation Research Phase I Program, Syscom Technology, Inc. (STI) will fabricate a metallized multifunctional composite fiber from a...

Deformation limits of polymer coated metal sheets

NARCIS (Netherlands)

Van Den Bosch, M.J.W.J.P.; Schreurs, P.J.G; Geers, M.G.D.

2005-01-01

Polymer coated metals are increasingly used by the packaging and automotive industry. During industrial deformation processes (drawing, roll-forming, bending etc.) the polymer-metal laminate is highly deformed at high deformation rates. These forming conditions can affect the mechanical integrity

Coupling Metallic Nanostructures to Thermally Responsive Polymers Allows the Development of Intelligent Responsive Membranes

Directory of Open Access Journals (Sweden)

J. Rubén Morones-Ramírez

2014-01-01

Full Text Available Development of porous membranes capable of controlling flow or changing their permeability to specific chemical entities, in response to small changes in environmental stimuli, is an area of appealing research, since these membranes present a wide variety of applications. The synthesis of these membranes has been mainly approached through grafting of environmentally responsive polymers to the surface walls of polymeric porous membranes. This synergizes the chemical stability and mechanical strength of the polymer membrane with the fast response times of the bonded polymer chains. Therefore, different composite membranes capable of changing their effective pore size with environmental triggers have been developed. A recent interest has been the development of porous membranes responsive to light, since these can achieve rapid, remote, noninvasive, and localized flow control. This work describes the synthesis pathway to construct intelligent optothermally responsive membranes. The method followed involved the grafting of optothermally responsive polymer-metal nanoparticle nanocomposites to polycarbonate track-etched porous membranes (PCTEPMs. The nanoparticles coupled to the polymer grafts serve as the optothermal energy converters to achieve optical switching of the pores. The results of the paper show that grafting of the polymer and in situ synthesis of the metallic particles can be easily achieved. In addition, the composite membranes allow fast and reversible switching of the pores using both light and heat permitting control of fluid flow.

Wood and concrete polymer composites

International Nuclear Information System (INIS)

Singer, K.

1974-01-01

There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

Reversible light-controlled conductance switching of azobenzene-based metal/polymer nanocomposites

International Nuclear Information System (INIS)

Pakula, Christina; Zaporojtchenko, Vladimir; Strunskus, Thomas; Faupel, Franz; Zargarani, Dordaneh; Herges, Rainer

2010-01-01

We present a new concept of light-controlled conductance switching based on metal/polymer nanocomposites with dissolved chromophores that do not have intrinsic current switching ability. Photoswitchable metal/PMMA nanocomposites were prepared by physical vapor deposition of Au and Pt clusters, respectively, onto spin-coated thin poly(methylmethacrylate) films doped with azo-dye molecules. High dye concentrations were achieved by functionalizing the azo groups with tails and branches, thus enhancing solubility. The composites show completely reversible optical switching of the absorption bands upon alternating irradiation with UV and blue light. We also demonstrate reversible light-controlled conductance switching. This is attributed to changes in the metal cluster separation upon isomerization based on model experiments where analogous conductance changes were induced by swelling of the composite films in organic vapors and by tensile stress.

Effects of Processing Parameters on the Forming Quality of C-Shaped Thermosetting Composite Laminates in Hot Diaphragm Forming Process

Science.gov (United States)

Bian, X. X.; Gu, Y. Z.; Sun, J.; Li, M.; Liu, W. P.; Zhang, Z. G.

2013-10-01

In this study, the effects of processing temperature and vacuum applying rate on the forming quality of C-shaped carbon fiber reinforced epoxy resin matrix composite laminates during hot diaphragm forming process were investigated. C-shaped prepreg preforms were produced using a home-made hot diaphragm forming equipment. The thickness variations of the preforms and the manufacturing defects after diaphragm forming process, including fiber wrinkling and voids, were evaluated to understand the forming mechanism. Furthermore, both interlaminar slipping friction and compaction behavior of the prepreg stacks were experimentally analyzed for showing the importance of the processing parameters. In addition, autoclave processing was used to cure the C-shaped preforms to investigate the changes of the defects before and after cure process. The results show that the C-shaped prepreg preforms with good forming quality can be achieved through increasing processing temperature and reducing vacuum applying rate, which obviously promote prepreg interlaminar slipping process. The process temperature and forming rate in hot diaphragm forming process strongly influence prepreg interply frictional force, and the maximum interlaminar frictional force can be taken as a key parameter for processing parameter optimization. Autoclave process is effective in eliminating voids in the preforms and can alleviate fiber wrinkles to a certain extent.

Analytical Modeling of the High Strain Rate Deformation of Polymer Matrix Composites

Science.gov (United States)

Goldberg, Robert K.; Roberts, Gary D.; Gilat, Amos

2003-01-01

The results presented here are part of an ongoing research program to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to high strain rate impact loads. State variable constitutive equations originally developed for metals have been modified in order to model the nonlinear, strain rate dependent deformation of polymeric matrix materials. To account for the effects of hydrostatic stresses, which are significant in polymers, the classical 5 plasticity theory definitions of effective stress and effective plastic strain are modified by applying variations of the Drucker-Prager yield criterion. To verify the revised formulation, the shear and tensile deformation of a representative toughened epoxy is analyzed across a wide range of strain rates (from quasi-static to high strain rates) and the results are compared to experimentally obtained values. For the analyzed polymers, both the tensile and shear stress-strain curves computed using the analytical model correlate well with values obtained through experimental tests. The polymer constitutive equations are implemented within a strength of materials based micromechanics method to predict the nonlinear, strain rate dependent deformation of polymer matrix composites. In the micromechanics, the unit cell is divided up into a number of independently analyzed slices, and laminate theory is then applied to obtain the effective deformation of the unit cell. The composite mechanics are verified by analyzing the deformation of a representative polymer matrix composite (composed using the representative polymer analyzed for the correlation of the polymer constitutive equations) for several fiber orientation angles across a variety of strain rates. The computed values compare favorably to experimentally obtained results.

Single-step generation of metal-plasma polymer multicore@shell nanoparticles from the gas phase.

Science.gov (United States)

Solař, Pavel; Polonskyi, Oleksandr; Olbricht, Ansgar; Hinz, Alexander; Shelemin, Artem; Kylián, Ondřej; Choukourov, Andrei; Faupel, Franz; Biederman, Hynek

2017-08-17

Nanoparticles composed of multiple silver cores and a plasma polymer shell (multicore@shell) were prepared in a single step with a gas aggregation cluster source operating with Ar/hexamethyldisiloxane mixtures and optionally oxygen. The size distribution of the metal inclusions as well as the chemical composition and the thickness of the shells were found to be controlled by the composition of the working gas mixture. Shell matrices ranging from organosilicon plasma polymer to nearly stoichiometric SiO 2 were obtained. The method allows facile fabrication of multicore@shell nanoparticles with tailored functional properties, as demonstrated here with the optical response.

Tribology of Polymer Matrix Composites (PMCs) Fabricated by Additive Manufacturing (AM)

Science.gov (United States)

Gupta, S.; Dunnigan, R.; Salem, A.; Kuentz, L.; Halbig, M. C.; Singh, M.

2016-01-01

The integral process of depositing thin layers of material, one after another, until the designed component is created is collectively referred to as Additive Manufacturing (AM). Fused deposition process (FDP) is a type of AM where feedstock is extruded into filaments which then are deposited by 3D printing, and the solidification occurs during cooling of the melt. Currently, complex structures are being fabricated by commercial and open source desktop 3D printers. Recently, metal powder containing composite filaments based on polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) have emerged, which could be utilized for multifunctional applications. For further deployment in the field, especially for aerospace and ground-based applications, it is critical to understand the tribological behavior of 3D printed materials. In this presentation, we will report the tribological behavior of different polymer matrix composites fabricated by fused deposition process. These results will be compared with the base polymer systems. During this study, the tribological behavior of all the samples will be evaluated with tab-on-disc method and compared for different metallic powder reinforcements.

PREPARATION OF A POLYMER ARTICLE FOR SELECTIVE METALLIZATION

DEFF Research Database (Denmark)

2008-01-01

The present invention relates to the field of selective metallization, and in particular to preparing a polymer article for selective metallization by submerging the article in a first liquid, and while submergedirradiate the article by a laser beam the area of the article on which the metal...... is to be deposited. An activation step, prior to the selective metallization, comprises submerging the article in an activation liquid for depositing seedparticles in the selected area. The irradiation of the selected area is proportionate so as to cause a temporary meltingof the polymer in the surface...... of the selected area of the polymer article. The invention is advantageous in that the preparation may be performed with a relatively high scan rate across the polymer article, and in that a quite limited use of toxic chemicals....

A modified SILCS contraceptive diaphragm for long-term controlled release of the HIV microbicide dapivirine.

Science.gov (United States)

Major, Ian; Boyd, Peter; Kilbourne-Brook, Maggie; Saxon, Gene; Cohen, Jessica; Malcolm, R Karl

2013-07-01

There is considerable interest in developing new multipurpose prevention technologies to address women's reproductive health needs. This study describes an innovative barrier contraceptive device--based on the SILCS diaphragm--that also provides long-term controlled release of the lead candidate anti-HIV microbicide dapivirine. Diaphragm devices comprising various dapivirine-loaded polymer spring cores overmolded with a nonmedicated silicone elastomer sheath were fabricated by injection molding processes. In vitro release testing, thermal analysis and mechanical characterization were performed on the devices. A diaphragm device containing a polyoxymethylene spring core loaded with 10% w/w dapivirine provided continuous and controlled release of dapivirine over a 6-month period, with a mean in vitro daily release rate of 174 mcg/day. The mechanical properties of the new diaphragm were closely matched to the SILCS diaphragm. The study demonstrates proof of concept for a dapivirine-releasing diaphragm with daily release quantities potentially capable of preventing HIV transmission. In discontinuous clinical use, release of dapivirine may be readily extended over 1 or more years. Copyright © 2013 Elsevier Inc. All rights reserved.

Arrays of hollow out-of-plane microneedles made by metal electrodeposition onto solvent cast conductive polymer structures

International Nuclear Information System (INIS)

Mansoor, I; Liu, Y; Stoeber, B; Häfeli, U O

2013-01-01

Transdermal drug delivery using microneedles is a technique to potentially replace hypodermic needles for injection of many vaccines and drugs. Fabrication of hollow metallic microneedles so far has been associated with time-consuming steps that restrict batch production of these devices. Here, we are presenting a novel method for making metallic microneedles with any desired height, spacing, and lumen size. In our process, we use solvent casting to coat a mold, which contains an array of pillars, with a conductive polymer composite layer. The conductive layer is then used as a seed layer in a metal electrodeposition process. To characterize the process, the conductivity of the polymer composite with respect to different filler concentrations was investigated. In addition, plasma etching of the polymer was characterized. The electroplating process was also studied further to control the thickness of the microneedle array plate. The strength of the microneedle devices was evaluated through a series of compression tests, while their performance for transdermal drug delivery was tested by injection of 2.28 µm fluorescent microspheres into animal skin. The fabricated metallic microneedles seem appropriate for subcutaneous delivery of drugs and microspheres. (paper)

Heavy Metal Removal by Chitosan and Chitosan Composite

International Nuclear Information System (INIS)

Abdel-Mohdy, F.A.; El-Sawy, S.; Ibrahim, M.S.

2005-01-01

Radiation grafting of diethyl aminoethyl methacrylate (DEAEMA) on chitosan to impart ion exchange properties and to be used for the separation of metal ions from waste water, was carried out. The effect of experimental conditions such as monomer concentration and the radiation dose on grafting were studied. On using chitosan, grafted chitosan and some chitosan composites in metal ion removal they show high up-take capacity for Cu 2+ and lower uptake capacities for the other divalent metal ions used (Zn and Co). Competitive study, performed with solutions containing mixture of metal salts, showed high selectivity for Cu 2+ than the other metal ion. Limited grafting of DEAEMA polymer -containing specific functional groups-onto the chitosan backbone improves the sorption performance

Polymer/Layered Silicate Nano composites

International Nuclear Information System (INIS)

Bakhit, M.E.E.H.

2012-01-01

Polymer–clay nano composites have attracted the attention of many researchers and experimental results are presented in a large number of recent papers and patents because of the outstanding mechanical properties and low gas permeabilities that are achieved in many cases. Polymer-clay nano composites are a new class of mineral-field polymer that contain relatively small amounts (<10%) of nanometer-sized clay particles. Polymer/clay nano composites have their origin in the pioneering research conducted at Toyota Central Research Laboratories and the first historical record goes back to 1987. The matrix was nylon-6 and the filler MMT. Because of its many advantages such as high mechanical properties, good gas barrier, flame retardation, etc. polymer/clay nano composites have been intensely investigated and is currently the subject of many research programs. Nano composite materials are commercially important and several types of products with different shapes and applications including food packaging films and containers, engine parts, dental materials, etc. are now available in markets. A number of synthesis routes have been developed in the recent years to prepare these materials, which include intercalation of polymers or prepolymers from solution, in-situ polymerization, melt intercalation etc. In this study, new nano composite materials were produced from the components of rubber (Nbr, SBR and EPDM) as the polymeric matrix and organically modified quaternary alkylammonium montmorillonite in different contents (3, 5, 7, and 10 phr) as the filler by using an extruder then, the rubber nano composite sheets were irradiated at a dose of 0, 50, 75, 100 and 150 KGy using Electron beam Irradiation technique as a crosslinking agent. These new materials can be characterized by using various analytical techniques including X-ray diffractometer XRD, Thermogravimetric analyzer TGA, scanning electron microscope (SEM), transmission electron microscope (TEM),Fourier transform

Technology and development of self-reinforced polymer composites

NARCIS (Netherlands)

Alcock, B.; Peijs, T.

2013-01-01

In recent years there has been an increasing amount of interest, both commercially and scientifically, in the emerging field of "self-reinforced polymer composites". These materials, which are sometimes also referred to as "single polymer composites", or "all-polymer composites", were first

Technology and Development of Self-Reinforced Polymer Composites

Science.gov (United States)

Alcock, Ben; Peijs, Ton

In recent years there has been an increasing amount of interest, both commercially and scientifically, in the emerging field of "self-reinforced polymer composites". These materials, which are sometimes also referred to as "single polymer composites", or "all-polymer composites", were first conceived in the 1970s, and are now beginning to appear in a range of commercial products. While high mechanical performance polymer fibres or tapes are an obvious precursor for composite development, various different technologies have been developed to consolidate these into two- or three-dimensional structures. This paper presents a review of the various processing techniques that have been reported in the literature for the manufacture of self-reinforced polymer composites from fibres or tapes of different polymers, and so exploit the fibre or tape performance in a commercial material or product.

Durable polymer-aerogel based superhydrophobic coatings, a composite material

Science.gov (United States)

Kissel, David J; Brinker, Charles Jeffrey

2014-03-04

Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

Durable polymer-aerogel based superhydrophobic coatings: a composite material

Science.gov (United States)

Kissel, David J.; Brinker, Charles Jeffrey

2016-02-02

Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

Evaluating All-Metal Valves for Use in a Tritium Environment

Energy Technology Data Exchange (ETDEWEB)

Houk, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Payton, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-09-28

In the tritium gas processing system, it is desired to minimize polymer components due to their degradation from tritium exposure (beta decay). One source of polymers in the tritium process is valve components. A vendor has been identified that manufactures a valve that is marketed as being made from all-metal construction. This manufacturer, Ham-Let Group, manufactures a diaphragm valve (3LE series) that claims to be made entirely of metal. SRNL procured twelve (12) Ham-Let diaphragm valves for characterization and evaluation. The characterization tests include identification of the maximum pressure of these valves by performing pressure and burst tests. Leak tests were performed to ensure the valves do not exceed the acceptable leak rate for tritium service. These valves were then cycled in a nitrogen gas and/or vacuum environment to ensure they would be durable in a process environment. They were subsequently leak tested per ASTM protocol to ensure that the valves maintained their leak tight integrity. A detailed material analysis was also conducted to determine hydrogen and tritium compatibility.

Modelling anisotropic water transport in polymer composite

Indian Academy of Sciences (India)

This work reports anisotropic water transport in a polymer composite consisting of an epoxy matrix reinforced with aligned triangular bars made of vinyl ester. By gravimetric experiments, water diffusion in resin and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation models were ...

High temperature performance of polymer composites

CERN Document Server

Keller, Thomas

2014-01-01

The authors explain the changes in the thermophysical and thermomechanical properties of polymer composites under elevated temperatures and fire conditions. Using microscale physical and chemical concepts they allow researchers to find reliable solutions to their engineering needs on the macroscale. In a unique combination of experimental results and quantitative models, a framework is developed to realistically predict the behavior of a variety of polymer composite materials over a wide range of thermal and mechanical loads. In addition, the authors treat extreme fire scenarios up to more than 1000°C for two hours, presenting heat-protection methods to improve the fire resistance of composite materials and full-scale structural members, and discuss their performance after fire exposure. Thanks to the microscopic approach, the developed models are valid for a variety of polymer composites and structural members, making this work applicable to a wide audience, including materials scientists, polymer chemist...

Metallization of Various Polymers by Cold Spray

Science.gov (United States)

Che, Hanqing; Chu, Xin; Vo, Phuong; Yue, Stephen

2018-01-01

Previous results have shown that metallic coatings can be successfully cold sprayed onto polymeric substrates. This paper studies the cold sprayability of various metal powders on different polymeric substrates. Five different substrates were used, including carbon fiber reinforced polymer (CFRP), acrylonitrile butadiene styrene (ABS), polyether ether ketone (PEEK), polyethylenimine (PEI); mild steel was also used as a benchmark substrate. The CFRP used in this work has a thermosetting matrix, and the ABS, PEEK and PEI are all thermoplastic polymers, with different glass transition temperatures as well as a number of distinct mechanical properties. Three metal powders, tin, copper and iron, were cold sprayed with both a low-pressure system and a high-pressure system at various conditions. In general, cold spray on the thermoplastic polymers rendered more positive results than the thermosetting polymers, due to the local thermal softening mechanism in the thermoplastics. Thick copper coatings were successfully deposited on PEEK and PEI. Based on the results, a method is proposed to determine the feasibility and deposition window of cold spraying specific metal powder/polymeric substrate combinations.

Modeling of an ionic polymer metal composite actuator based on an extended Kalman filter trained neural network

International Nuclear Information System (INIS)

Truong, Dinh Quang; Ahn, Kyoung Kwan

2014-01-01

An ion polymer metal composite (IPMC) is an electroactive polymer that bends in response to a small applied electric field as a result of mobility of cations in the polymer network and vice versa. This paper presents an innovative and accurate nonlinear black-box model (NBBM) for estimating the bending behavior of IPMC actuators. The model is constructed via a general multilayer perceptron neural network (GMLPNN) integrated with a smart learning mechanism (SLM) that is based on an extended Kalman filter with self-decoupling ability (SDEKF). Here the GMLPNN is built with an ability to autoadjust its structure based on its characteristic vector. Furthermore, by using the SLM based on the SDEKF, the GMLPNN parameters are optimized with small computational effort, and the modeling accuracy is improved. An apparatus employing an IPMC actuator is first set up to investigate the IPMC characteristics and to generate the data for training and validating the model. The advanced NBBM model for the IPMC system is then created with the proper inputs to estimate IPMC tip displacement. Next, the model is optimized using the SLM mechanism with the training data. Finally, the optimized NBBM model is verified with the validating data. A comparison between this model and the previously developed model is also carried out to prove the effectiveness of the proposed modeling technique. (paper)

A Compact Ionic Polymer Metal Composite (IPMC System with Inductive Sensor for Closed Loop Feedback

Directory of Open Access Journals (Sweden)

Jiaqi Wang

2015-05-01

Full Text Available Ionic polymer metal composite (IPMC, of which a low actuating voltage (<5 V, high power efficiency and biocompatibility makes it a proven candidate for low power devices. However, due to its inherent nonlinear behaviour and time-variance, feedback control, as well as reliable sensing means, are required for accurate operations. This paper presents an IPMC actuator implemented with an inductive sensor to enhance the reliability and compactness of the overall device. A practical, low cost and importantly, compact inductive sensor fabricated on a printed circuit board (PCB is proposed here. Target material selections and coil design considerations are discussed. It is experimentally determined that the inductive sensor has comparable performance to a laser sensor. Based on a proportional-integral-derivative (PID control results the inductive sensor has demonstrated to be an alternative to a laser sensor allowing devices using IPMC actuators to be compact.

Effects of heavy metals on the neuromuscular transmission of the mouse diaphragm

Energy Technology Data Exchange (ETDEWEB)

Fu, W M; Shiau, S Y.L.

1978-04-01

Effects of heavy metals including Mn, Co, Ni, Cd, Zn, Cu, Sr, Ba, and UO/sub 2//sup +/ ions on the neuromuscular transmission of the mouse diaphragm were studied and compared. From the dose-inhibition curves, the concentrations (mM) required to inhibit 50% of the contraction (ID/sub 50/) for Cd, Mn, Co, Ni, Zn and Sr are 0.03, 0.8, 0.75, 0.82, 1.2 and >20 respectively. In addition to the potent neuromuscular blocking action, both Cd and Zn induce a contracture of the mouse diaphram. Among the cations tested, Cu is the most potent in inducing the contracture. Mn does not cause a contracture, while Co and Ni induce a contracture only after a prolonged incubation for 3 hours. The neuromuscular blocking action of most of the cations tested can be completely or partially reversed by either high Ca or cysteine except the irreversible action of Zn and Cu. These findings suggest that most divalent cations block the neuromuscular transmission by binding to the -SH group of the cell membrane and inhibiting Ca influx. On the other hand, both Ba and UO/sub 2/ at low concentration increase but at high concentration inhibit the twitch response. Sine Ba increases the twitch response of the mouse diaphragm stimulated directly in the presence of d-tubocurarine as well as that stimulated indirectly, Ba/sup + +/ acts mainly directly on the muscle. In contrast, UO/sub 2//sup +/ ions at low concentration increases the twitch response possibly by releasing acetylcholine from the nerve endings.

Metal-containing radiation-sensitive polymers

International Nuclear Information System (INIS)

Lee, A.Y.

1986-01-01

The copolymers of methyl methacrylate with alkali metal salts (Na, K, and Cs) of methacrylic acid have been prepared by saponification K, and Cs) of methylacrylic acid have been prepared by saponification of the homopolymer poly(methyl methacrylate), PMMA. Low degrees of hydrolysis have been achieved by a heterogeneous system, and from the infrared spectra it has been confirmed that the ester groups of the methyl methacrylates are directly converted to the metal salts of methacrylic acid. These ionomers exhibit pseudo high molecular weights in gel permeation chromatogram, but no appreciable increase in intrinsic viscosities is observed in comparison to PMMA. The coordinated inorganic polymers poly[(dithio-2,2'-diacetato)bis(dimethylsulfoxide)dioxouranium(VI)] and poly[{methylenebis(thio)-2,2'-bis(acetato)}bis(dimethylsulfoxide)dioxouranium(VI)]have been synthesized in dimethyl sulfoxide solution with about 90% yield. The degree of polymerization and the number of average molecular weights of these polymers have been assessed by high resolution nuclear magnetic resonance, with which the acetato end group to the bridging ligand group ratios have been determined. The polymers bridging ligand group ratios have been determined. The polymers have been characterized by employing various techniques: infrared spectra, thermal gravimetric analysis, 13 C solid state nuclear magnetic resonance, and gel permeation chromatography. The prepared polymer samples have been subjected to various doses of 137 Cs gamma radiation under which the polymers predominantly undergo chain scission. The radiation sensitivities of the polymers are assessed by G values which are obtained from gel permeation chromatograms. These uranyl polymers exhibit unusually high G values

Experimental study on the thermal and mechanical properties of MWCNT/polymer and Cu/polymer composites

International Nuclear Information System (INIS)

Park, Hyeon Jeong; Badakhsh, Arash; Im, Ik Tae; Kim, Min-Soo; Park, Chan Woo

2016-01-01

Highlights: • MWCNTs and Cu were ball milled with a variation of milling times. • Thermal conductivity and tensile strength of the PMCs were measured. • Cu reinforced HDPE showed thermal conductivity improvement ratios of up to 2.7. • MWCNT/HDPE showed higher thermal conductivity than MWCNT/PP. • MWCNT/HDPE was found to be mechanically stronger than Cu/HDPE. - Abstract: In this study, the influence of the different conditions of powder treatment on the thermal conductivity of nanocomposites was investigated. Carbon and metal-based polymer composite materials were produced and their thermal and mechanical characteristics were studied. For the fabrication of the composites, the study has explored and proposed the use of MWCNT and Cu as fillers in a polymer matrix. The polymer matrices were thermoplastic resins-polypropylene (PP) and high density polyethylene (HDPE). Ball milling was used as the mechanical method in order to enhance the dispersion of MWCNT and the transformation of the Cu particles. The ball milled MWCNT and Cu powder were examined by field emission scanning electron microscopy (FE-SEM). The thermal conductivity values of the resultant nanocomposites were determined by laser flash method (LFM), indicating the highest thermal conductivity is possessed by the polymer composite reinforced by the highest amount of 60 min-treated powder in every case studied. Comparing the obtained values for thermal conductivity with that of pure polymer the maximum improvements were found to be 105.1%, 79% and 271.5% for MWCNT/PP, MWCNT/HDPE and Cu/HDPE, respectively. Furthermore, experimental results were validated using the Agari-Uno and Nielsen-Lewis thermal conductivity models considering the shape of the filler. The results of deviation were found to be within the maximum 5% of the exact value implying a fine agreement between experimental and modeling data. Also, the tensile strength test was performed to evaluate the tensile strength of thermally

Hydrostatic Stress Effects Incorporated Into the Analysis of the High-Strain-Rate Deformation of Polymer Matrix Composites

Science.gov (United States)

Goldberg, Robert K.; Roberts, Gary D.

2003-01-01

Procedures for modeling the effect of high strain rate on composite materials are needed for designing reliable composite engine cases that are lighter than the metal cases in current use. The types of polymer matrix composites that are likely to be used in such an application have a deformation response that is nonlinear and that varies with strain rate. The nonlinearity and strain rate dependence of the composite response is primarily due to the matrix constituent. Therefore, in developing material models to be used in the design of impact-resistant composite engine cases, the deformation of the polymer matrix must be correctly analyzed. However, unlike in metals, the nonlinear response of polymers depends on the hydrostatic stresses, which must be accounted for within an analytical model. An experimental program has been carried out through a university grant with the Ohio State University to obtain tensile and shear deformation data for a representative polymer for strain rates ranging from quasi-static to high rates of several hundred per second. This information has been used at the NASA Glenn Research Center to develop, characterize, and correlate a material model in which the strain rate dependence and nonlinearity (including hydrostatic stress effects) of the polymer are correctly analyzed. To obtain the material data, Glenn s researchers designed and fabricated test specimens of a representative toughened epoxy resin. Quasi-static tests at low strain rates and split Hopkinson bar tests at high strain rates were then conducted at the Ohio State University. The experimental data confirmed the strong effects of strain rate on both the tensile and shear deformation of the polymer. For the analytical model, Glenn researchers modified state variable constitutive equations previously used for the viscoplastic analysis of metals to allow for the analysis of the nonlinear, strain-rate-dependent polymer deformation. Specifically, we accounted for the effects of

Parametric study of roof diaphragm stiffness requirements

International Nuclear Information System (INIS)

Jones, W.D.; Tenbus, M.A.

1991-01-01

A common assumption made in performing a dynamic seismic analysis for a building is that the roof/floor system is open-quotes rigidclose quotes. This assumption would appear to be reasonable for many of the structures found in nuclear power plants, since many of these structures are constructed of heavily reinforced concrete having floor/roof slabs at least two feet in thickness, and meet the code requirements for structural detailing for seismic design. The roofs of many Department of Energy (DOE) buildings at the Oak Ridge Y-12 Plant in Oak Ridge, Tennessee, have roofs constructed of either metal, precast concrete or gypsum plank deck overlaid with rigid insulation, tar and gravel. In performing natural phenomena hazard assessments for one such facility, it was assumed that the existing roof performed first as a flexible diaphragm (zero stiffness) and then, rigid (infinitely stiff). For the flexible diaphragm model it was determined that the building began to experience significant damage around 0.09 g's. For the rigid diaphragm model it was determined that no significant damage was observed below 0.20 g's. A Conceptual Design Report has been prepared for upgrading/replacing the roof of this building. The question that needed to be answered here was, open-quotes How stiff should the new roof diaphragm be in order to satisfy the rigid diaphragm assumption and, yet, be cost effective?close quotes. This paper presents a parametric study of a very simple structural system to show that the design of roof diaphragms needs to consider both strength and stiffness (frequency) requirements. This paper shows how the stiffness of a roof system affects the seismically induced loads in the lateral, vertical load resisting elements of a building and provides guidance in determining how open-quotes rigidclose quotes a roof system should be in order to accomplish a cost effective design

Strengthening of the Timber Members Using Fibre Reinforced Polymer Composites

Directory of Open Access Journals (Sweden)

Ioana-Sorina Enţuc

2004-01-01

Full Text Available The reinforcement of structural wood products has become in the last decades an efficient method of improving structural capabilities of load carrying members made of this material. Some important steps in earlier stages of research were focused on using metallic reinforcement, including steel bars, prestressed stranded cables, and bonded steel and aluminum plates. A disadvantage of the metallic reinforcement was the poor compatibility between the wood and the reinforcing materials. In comparison with metallic reinforcement, fiber reinforced polymers (FRP composites are compatible with structural wood products leading to efficient hybrid members. Some interesting strengthening alternatives using FRP applied to wood beams and to wood columns are presented in this paper.

Nanoporous Polymer-Ceramic Composite Electrolytes for Lithium Metal Batteries

KAUST Repository

Tu, Zhengyuan

2013-09-16

A nanoporous composite material that offers the unique combination of high room-temperature ionic conductivity and high mechanical modulus is reported. When used as the separator/electrolyte in lithium batteries employing metallic lithium as anode, the material displays unprecedented cycling stability and excellent ability to prevent premature cell failure by dendrite-induced short circuits © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid, Selective Heavy Metal Removal from Water by a Metal-Organic Framework/Polydopamine Composite.

Science.gov (United States)

Sun, Daniel T; Peng, Li; Reeder, Washington S; Moosavi, Seyed Mohamad; Tiana, Davide; Britt, David K; Oveisi, Emad; Queen, Wendy L

2018-03-28

Drinking water contamination with heavy metals, particularly lead, is a persistent problem worldwide with grave public health consequences. Existing purification methods often cannot address this problem quickly and economically. Here we report a cheap, water stable metal-organic framework/polymer composite, Fe-BTC/PDA, that exhibits rapid, selective removal of large quantities of heavy metals, such as Pb 2+ and Hg 2+ , from real world water samples. In this work, Fe-BTC is treated with dopamine, which undergoes a spontaneous polymerization to polydopamine (PDA) within its pores via the Fe 3+ open metal sites. The PDA, pinned on the internal MOF surface, gains extrinsic porosity, resulting in a composite that binds up to 1634 mg of Hg 2+ and 394 mg of Pb 2+ per gram of composite and removes more than 99.8% of these ions from a 1 ppm solution, yielding drinkable levels in seconds. Further, the composite properties are well-maintained in river and seawater samples spiked with only trace amounts of lead, illustrating unprecedented selectivity. Remarkably, no significant uptake of competing metal ions is observed even when interferents, such as Na + , are present at concentrations up to 14 000 times that of Pb 2+ . The material is further shown to be resistant to fouling when tested in high concentrations of common organic interferents, like humic acid, and is fully regenerable over many cycles.

Flow measurement and thrust estimation of a vibrating ionic polymer metal composite

International Nuclear Information System (INIS)

Chae, Woojin; Cha, Youngsu; Peterson, Sean D; Porfiri, Maurizio

2015-01-01

Ionic polymer metal composites (IPMCs) are an emerging class of soft active materials that are finding growing application as underwater propulsors for miniature biomimetic swimmers. Understanding the hydrodynamics generated by an IPMC vibrating under water is central to the design of such biomimetic swimmers. In this paper, we propose the use of time-resolved particle image velocimetry to detail the fluid kinematics and kinetics in the vicinity of an IPMC vibrating along its fundamental structural mode. The reconstructed pressure field is ultimately used to estimate the thrust produced by the IPMC. The vibration frequency is systematically varied to elucidate the role of the Reynolds number on the flow physics and the thrust production. Experimental results indicate the formation and shedding of vortical structures from the IPMC tip during its vibration. Vorticity shedding is sustained by the pressure gradients along each side of the IPMC, which are most severe in the vicinity of the tip. The mean thrust is found to robustly increase with the Reynolds number, closely following a power law that has been derived from direct three-dimensional numerical simulations. A reduced order distributed model is proposed to describe IPMC underwater vibration and estimate thrust production, offering insight into the physics of underwater propulsion and aiding in the design of IPMC-based propulsors. (paper)

Processing and characterization of ceramic superconductor/polymer composites

International Nuclear Information System (INIS)

Kander, R.G.; Namboodri, S.L.

1993-01-01

One way to more easily process a brittle high-temperature ceramic superconductor into a useful structure is to combine it with a polymer to form a composite material. Processing of polymer-based composites into complex shapes is well established and relatively easy when compared with traditional ceramic processing unit operations. In addition, incorporating a ceramic superconductor into a polymer matrix can improve mechanical performance as compared with a monolithic ceramic. Finally, because ceramic superconductors are susceptible to attack by moisture, a polymer-based composite structure can also provide protection from deleterious environmental effects. This paper focuses on the processing and subsequent characterization of ceramic superconductor/polymer composites designed primarily for electromagnetic shielding and diamagnetic applications. YBa 2 Cu 3 O 7-x [YBCO] ceramic superconductor is combined with poly(methyl methacrylate) [PMMA] to form novel composite structures. Composite structures have been molded with both a discontinuous superconducting phase (i.e., ceramic particulate reinforced polymers) and with a continuous superconducting phase (i.e., polymer infiltrated porous ceramics). Characterization of these composite structures includes the determination of diamagnetic strength, electromagnetic shielding effectiveness, mechanical performance, and environmental resistance. The goal of this program is to produce a composite structure with increased mechanical integrity and environmental resistance at liquid nitrogen temperatures without compromising the electromagnetic shielding and diamagnetic properties of the superconducting phase. Composites structures of this type are potentially useful in numerous magnetic applications including electromagnetic shielding, magnetic sensors, energy storage, magnetic levitation, and motor windings

Design of pressure-sensing diaphragm for MEMS capacitance diaphragm gauge considering size effect

Science.gov (United States)

Li, Gang; Li, Detian; Cheng, Yongjun; Sun, Wenjun; Han, Xiaodong; Wang, Chengxiang

2018-03-01

MEMS capacitance diaphragm gauge with a full range of (1˜1000) Pa is considered for its wide application prospect. The design of pressure-sensing diaphragm is the key to achieve balanced performance for this kind of gauges. The optimization process of the pressure-sensing diaphragm with island design of a capacitance diaphragm gauge based on MEMS technique has been reported in this work. For micro-components in micro scale range, mechanical properties are very different from that in the macro scale range, so the size effect should not be ignored. The modified strain gradient elasticity theory considering size effect has been applied to determine the bending rigidity of the pressure-sensing diaphragm, which is then used in the numerical model to calculate the deflection-pressure relation of the diaphragm. According to the deflection curves, capacitance variation can be determined by integrating over the radius of the diaphragm. At last, the design of the diaphragm has been optimized based on three parameters: sensitivity, linearity and ground capacitance. With this design, a full range of (1˜1000) Pa can be achieved, meanwhile, balanced sensitivity, resolution and linearity can be kept.

Experimental verification of displacement control on integrated ionic polymer-metal composite actuators with stochastic on/off controller

Science.gov (United States)

Kimura, Keishiro; Kamamichi, Norihiro

2017-04-01

An ionic polymer-metal composite (IPMC) actuator is one of polymer-based soft actuators. It is produced by chemically plating gold or platinum on both surface of a perfluorosulfonic acid membrane which is known as an ion-exchange membrane. It is able to be activated by a simple driving circuit and generate a large deformation under a low applied voltage (0.5-3 V). However, individual difference and characteristics changes from environmental conditions should be considered for realizing a stable or precise control. To solve these problems, we applied a stochastic ON/OFF controller to an integrated IPMC actuator with parallel connections. The controller consists of a central controller and distributed controllers. The central controller broadcasts a control signal such as an error signal to distributed controllers uniformly. The distributed controllers switch the ON/OFF states based on the broadcasted signal stochastically. The central controller dose not measure the states of each IPMC actuator, and the control signals is calculated by using the output signal of the integrated actuator and reference signal. The validity of the applied method was investigated through numerical simulations and experiments.

Extrudable polymer-polymer composites based on ultra-high molecular weight polyethylene

Science.gov (United States)

Panin, S. V.; Kornienko, L. A.; Alexenko, V. O.; Buslovich, D. G.; Dontsov, Yu. V.

2017-12-01

Mechanical and tribotechnical characteristics of polymer-polymeric composites of UHMWPE are studied with the aim of developing extrudable, wear-resistant, self-lubricant polymer mixtures for Additive Manufacturing (AM). The motivation of the study is their further application as feedstocks for 3D printing. Blends of UHMWPE with graft- and block copolymers of low-density polyethylene (HDPE-g-VTMS, HDPE-g-SMA, HDPE-b-EVA), polypropylene (PP), block copolymers of polypropylene and polyamide with linear low density polyethylene (PP-b-LLDPE, PA-b-LLDPE), as well as cross-linked polyethylene (PEX-b), are examined. The choice of compatible polymer components for an ultra- high molecular weight matrix for increasing processability (extrudability) is motivated by the search for commercially available and efficient additives aimed at developing wear-resistant extrudable polymer composites for additive manufacturing. The extrudability, mechanical properties and wear resistance of UHMWPE-based polymer-polymeric composites under sliding friction with different velocities and loads are studied.

Facile and scalable fabrication of polymer-ceramic composite electrolyte with high ceramic loadings

Science.gov (United States)

Pandian, Amaresh Samuthira; Chen, X. Chelsea; Chen, Jihua; Lokitz, Bradley S.; Ruther, Rose E.; Yang, Guang; Lou, Kun; Nanda, Jagjit; Delnick, Frank M.; Dudney, Nancy J.

2018-06-01

Solid state electrolytes are a promising alternative to flammable liquid electrolytes for high-energy lithium battery applications. In this work polymer-ceramic composite electrolyte membrane with high ceramic loading (greater than 60 vol%) is fabricated using a model polymer electrolyte poly(ethylene oxide) + lithium trifluoromethane sulfonate and a lithium-conducting ceramic powder. The effects of processing methods, choice of plasticizer and varying composition on ionic conductivity of the composite electrolyte are thoroughly investigated. The physical, structural and thermal properties of the composites are exhaustively characterized. We demonstrate that aqueous spray coating followed by hot pressing is a scalable and inexpensive technique to obtain composite membranes that are amazingly dense and uniform. The ionic conductivity of composites fabricated using this protocol is at least one order of magnitude higher than those made by dry milling and solution casting. The introduction of tetraethylene glycol dimethyl ether further increases the ionic conductivity. The composite electrolyte's interfacial compatibility with metallic lithium and good cyclability is verified by constructing lithium symmetrical cells. A remarkable Li+ transference number of 0.79 is discovered for the composite electrolyte.

Stress-tuned conductor-polymer composite for use in sensors

Science.gov (United States)

Martin, James E; Read, Douglas H

2013-10-22

A method for making a composite polymeric material with electrical conductivity determined by stress-tuning of the conductor-polymer composite, and sensors made with the stress-tuned conductor-polymer composite made by this method. Stress tuning is achieved by mixing a miscible liquid into the polymer precursor solution or by absorbing into the precursor solution a soluble compound from vapor in contact with the polymer precursor solution. The conductor may or may not be ordered by application of a magnetic field. The composite is formed by polymerization with the stress-tuning agent in the polymer matrix. The stress-tuning agent is removed following polymerization to produce a conductor-polymer composite with a stress field that depends on the amount of stress-tuning agent employed.

Failure of structural elements made of polymer supported composite materials during the multiyear natural aging

Science.gov (United States)

Blinkov, Pavel; Ogorodov, Leonid; Grabovyy, Peter

2018-03-01

Modern high-rise construction introduces a number of limitations and tasks. In addition to durability, comfort and profitability, projects should take into account energy efficiency and environmental problems. Polymer building materials are used as substitutes for materials such as brick, concrete, metal, wood and glass, and in addition to traditional materials. Plastic materials are light, can be formed into complex shapes, durable and low, and also possess a wide range of properties. Plastic materials are available in various forms, colors and textures and require minimal or no color. They are resistant to heat transfer and diffusion of moisture and do not suffer from metal corrosion or microbial attack. Polymeric materials, including thermoplastics, thermoset materials and wood-polymer composites, have many structural and non-structural applications in the construction industry. They provide unique and innovative solutions at a low cost, and their use is likely to grow in the future. A number of polymer composite materials form complex material compositions, which are applied in the construction in order to analyze the processes of damage accumulation under the conditions of complex nonstationary loading modes, and to determine the life of structural elements considering the material aging. This paper present the results of tests on short-term compression loading with a deformation rate of v = 2 mm/min using composite samples of various shapes and sizes.

MOFwich: Sandwiched Metal-Organic Framework-Containing Mixed Matrix Composites for Chemical Warfare Agent Removal.

Science.gov (United States)

Peterson, Gregory W; Lu, Annie X; Hall, Morgan G; Browe, Matthew A; Tovar, Trenton; Epps, Thomas H

2018-02-28

This work describes a new strategy for fabricating mixed matrix composites containing layered metal-organic framework (MOF)/polymer films as functional barriers for chemical warfare agent protection. Through the use of mechanically robust polymers as the top and bottom encasing layers, a high-MOF-loading, high-performance-core layer can be sandwiched within. We term this multifunctional composite "MOFwich". We found that the use of elastomeric encasing layers enabled core layer reformation after breakage, an important feature for composites and membranes alike. The incorporation of MOFs into the core layer led to enhanced removal of chemical warfare agents while simultaneously promoting moisture vapor transport through the composite, showcasing the promise of these composites for protection applications.

Diaphragm flange and method for lowering particle beam impedance at connected beam tubes of a particle accelerator

Energy Technology Data Exchange (ETDEWEB)

Biallas, George Herman

2017-07-04

A diaphragm flange for connecting the tubes in a particle accelerator while minimizing beamline impedance. The diaphragm flange includes an outer flange and a thin diaphragm integral with the outer flange. Bolt holes in the outer flange provide a means for bolting the diaphragm flange to an adjacent flange or beam tube having a mating bolt-hole pattern. The diaphragm flange includes a first surface for connection to the tube of a particle accelerator beamline and a second surface for connection to a CF flange. The second surface includes a recessed surface therein and a knife-edge on the recessed surface. The diaphragm includes a thickness that enables flexing of the integral diaphragm during assembly of beamline components. The knife-edge enables compression of a soft metal gasket to provide a leak-tight seal.

Fluid Effects in Polymers and Polymeric Composites

CERN Document Server

Weitsman, Y Jack

2012-01-01

Fluid Effects in Polymers and Polymeric Composites, written by the late Dr. Y. Jack Weitsman, addresses the wide range of parameters that affect the interaction of fluids with polymers and polymeric composites. The book aims at broadening the scope of available data, mostly limited up to this time to weight-gain recordings of fluid ingress into polymers and composites, to the practical circumstances of fluctuating exposure. Various forms of experimental data are given, in conjunction with theoretical models derived from basic scientific principles, and correlated with severity of exposure conditions and interpreted by means of rationally based theoretical models. The practical implications of the effects of fluids are discussed. The issue of fluid effects on polymers and polymeric composites is of concern to engineers and scientists active in aerospace and naval structures, as an increasing portion of these structures are made of polymeric composites and employ polymeric adhesives as a joining device. While...

Inorganic-whisker-reinforced polymer composites synthesis, properties and applications

CERN Document Server

Sun, Qiuju

2015-01-01

Inorganic-Whisker-Reinforced Polymer Composites: Synthesis, Properties and Applications gives a comprehensive presentation of inorganic microcrystalline fibers, or whiskers, a polymer composite filler. It covers whisker synthesis, surface modification, applications for reinforcing polymer-matrix composites, and analysis of resulting filled polymer composites. It focuses on calcium carbonate whiskers as a primary case study, introducing surface treatment methods for calcium carbonate whiskers and factors that influence them. Along with calcium carbonate, the book discusses potassium titanate and aluminum borate whiskers, which also comprise the new generation of inorganic whiskers. According to research results, composites filled by inorganic whiskers show improved strength, wear-resistance, thermal conductivity, and antistatic properties. It explains the importance of modifying polymer materials for use with inorganic whiskers and describes preparation and evaluation methods of polymers filled with inorganic ...

Physicochemical and Electrophysical Properties of Metal/Semiconductor Containing Nanostructured Composites

Science.gov (United States)

Gerasimov, G. N.; Gromov, V. F.; Trakhtenberg, L. I.

2018-06-01

The properties of nanostructured composites based on metal oxides and metal-polymer materials are analyzed, along with ways of preparing them. The effect the interaction between metal and semiconductor nanoparticles has on the conductivity, photoconductivity, catalytic activity, and magnetic, dielectric, and sensor properties of nanocomposites is discussed. It is shown that as a result of this interaction, a material can acquire properties that do not exist in systems of isolated particles. The transfer of electrons between metal particles of different sizes in polymeric matrices leads to specific dielectric losses, and to an increase in the rate and a change in the direction of chemical reactions catalyzed by these particles. The interaction between metal-oxide semiconductor particles results in the electronic and chemical sensitization of sensor effects in nanostructured composite materials. Studies on creating molecular machines (Brownian motors), devices for magnetic recording of information, and high-temperature superconductors based on nanostructured systems are reviewed.

Tribology of natural fiber polymer composites

CERN Document Server

Chand, N

2008-01-01

Environmental concerns are driving demand for bio-degradable materials such as plant-based natural fiber reinforced polymer composites. These composites are fast replacing conventional materials in many applications, especially in automobiles, where tribology (friction, lubrication and wear) is important. This book covers the availability and processing of natural fiber polymer composites and their structural, thermal, mechanical and, in particular, tribological properties.Chapter 1 discusses sources of natural fibers, their extraction and surface modification. It also reviews the ther

Polymer quenched prealloyed metal powder

Science.gov (United States)

Hajaligol, Mohammad R.; Fleischhauer, Grier; German, Randall M.

2001-01-01

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3 % Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

Polymer-metal organic framework composite films as affinity layer for capacitive sensor devices

NARCIS (Netherlands)

Sachdeva, Sumit; Soccol, Dimitri; Gravesteijn, Dirk J.; Kapteijn, Freek; Sudhölter, E.J.R.; Gascon, Jorge; Smet, de L.C.P.M.

2016-01-01

We report a simple method for sensor development using polymer-
MOF composite films. Nanoparticles of NH2-MIL-53(Al) dispersed in a Matrimid
polyimide were applied as a thin film on top of capacitive sensor devices with planar electrodes. These drop-cast films act as an affinity layer.

Graphene–Noble Metal Nano-Composites and Applications for Hydrogen Sensors

Directory of Open Access Journals (Sweden)

Sukumar Basu

2017-10-01

Full Text Available Graphene based nano-composites are relatively new materials with excellent mechanical, electrical, electronic and chemical properties for applications in the fields of electrical and electronic devices, mechanical appliances and chemical gadgets. For all these applications, the structural features associated with chemical bonding that involve other components at the interface need in-depth investigation. Metals, polymers, inorganic fibers and other components improve the properties of graphene when they form a kind of composite structure in the nano-dimensions. Intensive investigations have been carried out globally in this area of research and development. In this article, some salient features of graphene–noble metal interactions and composite formation which improve hydrogen gas sensing properties—like higher and fast response, quick recovery, cross sensitivity, repeatability and long term stability of the sensor devices—are presented. Mostly noble metals are effective for enhancing the sensing performance of the graphene–metal hybrid sensors, due to their superior catalytic activities. The experimental evidence for atomic bonding between metal nano-structures and graphene has been reported in the literature and it is theoretically verified by density functional theory (DFT. Multilayer graphene influences gas sensing performance via intercalation of metal and non-metal atoms through atomic bonding.

Development of ceramic composites from mixture of alumina and ceramic precursor polymer poly (silsesquioxane))

International Nuclear Information System (INIS)

Machado, Glauson Aparecido Ferreira

2009-01-01

Processing of ceramics materials, by polymer precursors pyrolysis, has been intensively researched over the past decades, due to advantages that this path provides, such as: lower temperature process compared to conventional techniques; structure control at molecular level; synthesis possibility of a wide range of ceramic compounds; obtaining parts with dimensions of the final product etc. The active filler controlled polymer pyrolysis (AFCOP) process, enables the synthesis of ceramic composites, by reaction between added filler (oxides, metals, intermetallic etc.) and solid and gaseous products, from polymer decomposition. In this study, based on this process, samples of alumina, with addition of 10 and 20 mass% of poly silsesquioxane polymer precursor, were manufactured. These samples were pyrolyzed at 900 degree C and thermal treated at temperatures of 1100, 1300 and 1500 degree C. The samples were characterized for bulk density, porosity and hardness, after each stage of thermal treatment. Structural transformations were analyzed by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. Samples treated until 1300 degree C resulted in composites of alumina and silicon oxycarbide, while those treated at 1500 degree C, formed composites of mullite and alumina. The samples with 20% of polymer added started to density around 800 degree C and high retraction rate was observed at 1400 degree C. (author)

High-Temperature Polymer Composites Tested for Hypersonic Rocket Combustor Backup Structure

Science.gov (United States)

Sutter, James K.; Shin, E. Eugene; Thesken, John C.; Fink, Jeffrey E.

2005-01-01

Significant component weight reductions are required to achieve the aggressive thrust-toweight goals for the Rocket Based Combined Cycle (RBCC) third-generation, reusable liquid propellant rocket engine, which is one possible engine for a future single-stage-toorbit vehicle. A collaboration between the NASA Glenn Research Center and Boeing Rocketdyne was formed under the Higher Operating Temperature Propulsion Components (HOTPC) program and, currently, the Ultra-Efficient Engine Technology (UEET) Project to develop carbon-fiber-reinforced high-temperature polymer matrix composites (HTPMCs). This program focused primarily on the combustor backup structure to replace all metallic support components with a much lighter polymer-matrixcomposite- (PMC-) titanium honeycomb sandwich structure.

Developing polymer composite materials: carbon nanotubes or graphene?

Science.gov (United States)

Sun, Xuemei; Sun, Hao; Li, Houpu; Peng, Huisheng

2013-10-04

The formation of composite materials represents an efficient route to improve the performances of polymers and expand their application scopes. Due to the unique structure and remarkable mechanical, electrical, thermal, optical and catalytic properties, carbon nanotube and graphene have been mostly studied as a second phase to produce high performance polymer composites. Although carbon nanotube and graphene share some advantages in both structure and property, they are also different in many aspects including synthesis of composite material, control in composite structure and interaction with polymer molecule. The resulting composite materials are distinguished in property to meet different applications. This review article mainly describes the preparation, structure, property and application of the two families of composite materials with an emphasis on the difference between them. Some general and effective strategies are summarized for the development of polymer composite materials based on carbon nanotube and graphene. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Poly(vinylidene fluoride) modification induced by gamma irradiation for application as ionic polymer-metal composite

International Nuclear Information System (INIS)

Ferreira, Henrique Perez

2011-01-01

Gamma-radiation-induced grafting of styrene into poly(vinylidene fluoride) (PVDF) films with 0.125 mm thickness at doses from 1 to 100 kGy in the presence of a styrene/N,N- dimethylformamide (DMF) solution (1:1, v/v) and styrene/toluene (1:1, v/v) at dose rate of 5 kGy h-1 was carried out by simultaneous method under nitrogen atmosphere at room temperature, using gamma rays from a Co-60. After grafting reactions, the polymer was then sulfonated in chlorosulfonic acid/1,2-dichloroethane (2 and 10%) for 3 hours. The films were characterized before and after modification by calculating the degree of grafting (DOG), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). DOG results show that grafting increases with dose, and varies enormously depending on the solvent used, with DOGs about 20 times greater in DMF than in toluene. It was possible to confirm the grafting of styrene by FT-IR due to the appearance of the new characteristic peaks and by the TG and DSC which exhibited changes in the thermal behavior of the grafted/sulfonated material. Sulfonated material was also characterized by ion exchange capacity (IEC) showed that both DOG and sulfonic acid concentration increase IEC values. Results showed that it is possible to obtain materials with ion exchange capacity of possible application as ionic polymer-metal composites. (author)

Selective removal of heavy metal ions by disulfide linked polymer networks

Energy Technology Data Exchange (ETDEWEB)

Ko, Dongah [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Lee, Joo Sung [Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141 (Korea, Republic of); Patel, Hasmukh A. [Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States); Jakobsen, Mogens H. [Department of Micro and Nano technology, Technical University of Denmark, Ørsteds Plads, 345B, 2800 Kgs. Lyngby (Denmark); Hwang, Yuhoon [Department of Environmental Engineering, Seoul National University of Science and Technology, 232 Gongreung-ro, Nowon-gu, Seoul 01811 (Korea, Republic of); Yavuz, Cafer T. [Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141 (Korea, Republic of); Hansen, Hans Chr. Bruun [Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Andersen, Henrik R., E-mail: henrik@ndersen.net [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark)

2017-06-15

Highlights: • Disulfide/thiol polymer networks are promising as sorbent for heavy metals. • Rapid sorption and high Langmuir affinity constant (a{sub L}) for stormwater treatment. • Selective sorption for copper, cadmium, and zinc in the presence of calcium. • Reusability likely due to structure stability of disulfide linked polymer networks. - Abstract: Heavy metal contaminated surface water is one of the oldest pollution problems, which is critical to ecosystems and human health. We devised disulfide linked polymer networks and employed as a sorbent for removing heavy metal ions from contaminated water. Although the polymer network material has a moderate surface area, it demonstrated cadmium removal efficiency equivalent to highly porous activated carbon while it showed 16 times faster sorption kinetics compared to activated carbon, owing to the high affinity of cadmium towards disulfide and thiol functionality in the polymer network. The metal sorption mechanism on polymer network was studied by sorption kinetics, effect of pH, and metal complexation. We observed that the metal ions–copper, cadmium, and zinc showed high binding affinity in polymer network, even in the presence of competing cations like calcium in water.

Selective removal of heavy metal ions by disulfide linked polymer networks

DEFF Research Database (Denmark)

Ko, Dongah; Sung Lee, Joo; Patel, Hasmukh A.

2017-01-01

Heavy metal contaminated surface water is one of the oldest pollution problems, which is critical to ecosystems and human health. We devised disulfide linked polymer networks and employed as a sorbent for removing heavy metal ions from contaminated water. Although the polymer network material has...... a moderate surface area, it demonstrated cadmium removal efficiency equivalent to highly porous activated carbon while it showed 16 times faster sorption kinetics compared to activated carbon, owing to the high affinity of cadmium towards disulfide and thiol functionality in the polymer network. The metal...... sorption mechanism on polymer network was studied by sorption kinetics, effect of pH, and metal complexation. We observed that the metal ions―copper, cadmium, and zinc showed high binding affinity in polymer network, even in the presence of competing cations like calcium in water....

Ion Implantation of Polymers

DEFF Research Database (Denmark)

Popok, Vladimir

2012-01-01

The current paper presents a state-of-the-art review in the field of ion implantation of polymers. Numerous published studies of polymers modified by ion beams are analysed. General aspects of ion stopping, latent track formation and changes of structure and composition of organic materials...... are discussed. Related to that, the effects of radiothermolysis, degassing and carbonisation are considered. Specificity of depth distributions of implanted into polymers impurities is analysed and the case of high-fluence implantation is emphasised. Within rather broad topic of ion bombardment, the focus...... is put on the low-energy implantation of metal ions causing the nucleation and growth of nanoparticles in the shallow polymer layers. Electrical, optical and magnetic properties of metal/polymer composites are under the discussion and the approaches towards practical applications are overviewed....

The analysis of thermoplastic characteristics of special polymer sulfur composite

Science.gov (United States)

Książek, Mariusz

2017-01-01

Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

Nanoporous metal-carbon composite

Science.gov (United States)

Worsley, Marcus A.; Satcher, Joe; Kucheyev, Sergei; Charnvanichborikarn, Supakit; Colvin, Jeffrey; Felter, Thomas; Kim, Sangil; Merrill, Matthew; Orme, Christine

2017-12-19

Described here is a metal-carbon composite, comprising (a) a porous three-dimensional scaffold comprising one or more of carbon nanotubes, graphene and graphene oxide, and (b) metal nanoparticles disposed on said porous scaffold, wherein the metal-carbon composite has a density of 1 g/cm.sup.3 or less, and wherein the metal nanoparticles account for 1 wt. % or more of the metal-carbon composite. Also described are methods for making the metal-carbon composite.

A review of electrohydrodynamic casting energy conversion polymer composites

Directory of Open Access Journals (Sweden)

Yong X. Gan

2018-03-01

Full Text Available This paper provides a brief review on manufacturing polymer composite materials through the nontraditional electrohydrodynamic (EHD casting approach. First, the EHD technology will be introduced. Then, typical functional polymer composite materials including thermoelectric and photoelectric energy conversion polymers and their composites will be presented. Specifically, how to make composite materials containing functional nanoparticles will be discussed. Converting polymeric fibers into partially carbonized fiber composites will also be shown. The latest research results of polymeric composite materials with energy conversion and sensing functions will be given.

Conductive polymer composition

NARCIS (Netherlands)

2010-01-01

The present invention relates to a process for the preparation of a conductive polymer composition comprising graphene and the articles obtained by this process. The process comprises the following steps: A) contacting graphite oxide in an aqueous medium with a water-soluble or dispersible

Multilayer Electroactive Polymer Composite Material Comprising Carbon Nanotubes

Science.gov (United States)

Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

2009-01-01

An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

Traumatic rupture of the diaphragm: CT findings

International Nuclear Information System (INIS)

Cho, Sung Tae; Kim, Sung Jin; Cha, Sang Hoon; Park, Kil Sun; Kim, Jin Hee; Yim, Se Hwan

1995-01-01

The aim of this study was to assess the clinical utility of the known CT signs of the traumatic rupture of the diaphragm. CT scans and chest radiographs were retrospectively reviewed in 13 patients who had diaphragmatic rupture confirmed by surgery. On chest radiographs the elevation of the diaphragm was evaluated. On CT, 1) discontinuity of the diaphragm, 2) lack of depiction of the diaphragm surrounding the herniated intraabdominal organs (absent diaphragm sign), and 3) fat seen lateral to the diaphragm (fat sign) were evaluated. Chest radiographs showed the elevation of the diaphragm in 11 patients (85%). CT scan showed absent diaphragm sign in 11 patients (85%), discontinuity of the diaphragm in 8 (62%), and fat sign in 7 (54%). All of 12 patients who had the left diaphragmatic rupture had one or more of the above findings. Discontinuity of the diaphragm, absent diaphragm sign, and fat sign may be helpful CT findings in the diagnosis of the traumatic rupture of the left diaphragm

21 CFR 888.3350 - Hip joint metal/polymer semi-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer semi-constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3350 Hip joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A hip joint metal/polymer semi...

21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/polymer non-constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3120 Ankle joint metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non...

Density-tunable lightweight polymer composites with dual-functional ability of efficient EMI shielding and heat dissipation.

Science.gov (United States)

Lee, Seung Hwan; Yu, Seunggun; Shahzad, Faisal; Kim, Woo Nyon; Park, Cheolmin; Hong, Soon Man; Koo, Chong Min

2017-09-21

Lightweight dual-functional materials with high EMI shielding performance and thermal conductivity are of great importance in modern cutting-edge applications, such as mobile electronics, automotive, aerospace, and military. Unfortunately, a clear material solution has not emerged yet. Herein, we demonstrate a simple and effective way to fabricate lightweight metal-based polymer composites with dual-functional ability of excellent EMI shielding effectiveness and thermal conductivity using expandable polymer bead-templated Cu hollow beads. The low-density Cu hollow beads (ρ ∼ 0.44 g cm -3 ) were fabricated through electroless plating of Cu on the expanded polymer beads with ultralow density (ρ ∼ 0.02 g cm -3 ). The resulting composites that formed a continuous 3D Cu network with a very small Cu content (∼9.8 vol%) exhibited excellent EMI shielding (110.7 dB at 7 GHz) and thermal conductivity (7.0 W m -1 K -1 ) with isotropic features. Moreover, the densities of the composites are tunable from 1.28 to 0.59 g cm -3 in accordance with the purpose of their applications. To the best of our knowledge, the resulting composites are the best lightweight dual-functional materials with exceptionally high EMI SE and thermal conductivity performance among synthetic polymer composites.

Polymer-Oxide Nanolayer/Al Composite Cathode for Efficient Polymer Light-Emitting Diodes

National Research Council Canada - National Science Library

Guo, Tzung-Fang; Wen, Ten-Chin

2007-01-01

...). The author proposed to place a salt-free, polymer-oxide nanolayer at the interface between the light-emissive polymer layer with Al as the device cathode instead of using low work function metals, such as Ca or LiF/Al...

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

Formation of TiC/Al{sub 2}O{sub 3} composites from metal-polymer-precursors

Energy Technology Data Exchange (ETDEWEB)

Jost, H.; Braun, M.; Staedler, C. [Technische Univ. Berlin (Germany). Inst. fuer Nichtmetallische Werkstoffe

2002-07-01

A new synthesis route for TiC/Al{sub 2}O{sub 3} materials was developed starting from a mixed metal-polymer precursor. The Precursor was prepared from aluminium nitrate, titantetrachloride and polymethacrylic acid dissolved in a solvent in order to achieve a high homogeneity of the precursor reactants. (orig.)

Metallic composite materials

International Nuclear Information System (INIS)

Frommeyer, G.

1987-01-01

The structure and properties of metallic composite materials and composite materials with metallic matrix are considered. In agreement with the morphology of constituent phases the following types of composite materials are described: dispersion-strengthened composite materials; particle-reinforced composite materials; fibrous composite materials; laminar composite materials. Data on strength and electric properties of the above-mentioned materials, as well as effect of the amount, location and geometric shape of the second phase on them, are presented

Ionochromic effects and structures of metalated poly(p-phenylenevinylene) polymers incorporating 2,2'-bipyridines

International Nuclear Information System (INIS)

Chen, L.X.; Jager, W.J.H.; Gosztola, D.J.; Niemczyk, M.P.; Wasielewski, M.R.

2000-01-01

The effects of metal ion chelation to the 2,2'-bipyridine (bpy) groups on the photophysics and exciton dynamics of two conjugated polymers 1 and 2 in solution are investigated. The structures of polymers 1 and 2 have 2,2'-bipyridyl-5-vinylene units that alternate with one and three 2,5-bis(n-decyloxy)-1,4-phenylenevinylene monomer units, respectively. The photophysics and exciton dynamics of metalated polymers 1 and 2 are compared to those of the metal-free polymers (Chen et al. J. Phys. Chem. A 1999, 103, 4341-4351). The origins of ionochromic effects due the metal ion chelation were studied using both steady-state and transient optical spectroscopy, and the results indicate that both conformational flattening and participation of Jr electrons from the metal in the π-conjugation of the polymer backbone play important roles in metal ion binding induced red shifts in absorption and photoluminescence spectra. The photoluminescence properties of the metalated polymers are determined by the metal ion electronic structures, where the closed shell Zn 2+ -bound polymer 2 has an increased photoluminescence quantum yield and the corresponding open shell Ni 2+ - or Fe 3+ -bound polymers have quenched photoluminescence due to spin-orbit coupling. The dual character of metalated polymer 2 as a conjugated polymer and as a metal-bpy complex is discussed. In addition, the structures of metal ion binding sites are studied via X-ray absorption fine structure (XAFS) and are related to the photophysical properties of the metalated polymers

Physical masking process for integrating micro metallic structures on polymer substrate

DEFF Research Database (Denmark)

Islam, Mohammad Aminul; Hansen, Hans Nørgaard

2009-01-01

plasmon devices need micro metallic structures on a polymer substrate with an uniform metal layer thickness in the nanometer range. A well known fabrication process to achieve such metallic surface pattern on polymer substrate is photolithography which involves an expensive mask and toxic chemicals......Integration of micro metallic structures in polymer devices is a broad multi-disciplinary research field, consisting of various combinations of mechanical, chemical and physical fabrication methods. Each of the methods has its specific advantages and disadvantages. Some applications like surface....... The current study shows a novel approach for fabricating thin micro metallic structures on polymer substrates using a simple physical mask and a PVD equipment. The new process involves fewer process steps, it is cost effective and suitable for high volume industrial production. Current study suggests...

Effect of maternal steroid on developing diaphragm integrity.

Directory of Open Access Journals (Sweden)

Yong Song

Full Text Available Antenatal steroids reduce the severity of initial respiratory distress of premature newborn babies but may have an adverse impact on other body organs. The study aimed to examine the effect of maternal steroids on postnatal respiratory muscle function during development and elucidate the mechanisms underlying the potential myopathy in newborn rats. Pregnant rats were treated with intramuscular injections of 0.5 mg/kg betamethasone 7 d and 3 d before birth. Newborn diaphragms were dissected for assessment of contractile function at 2 d, 7 d or 21 d postnatal age (PNA, compared with age-matched controls. The expression of myosin heavy chain (MHC isoforms and atrophy-related genes and activity of intracellular molecular signalling were measured using quantitative PCR and/or Western blot. With advancing PNA, neonatal MHC gene expression decreased progressively while MHC IIb and IIx isoforms increased. Protein metabolic signalling showed high baseline activity at 2 d PNA, and significantly declined at 7 d and 21 d. Antenatal administration of betamethasone significantly decreased diaphragm force production, fatigue resistance, total fast fibre content and anabolic signalling activity (Akt and 4E-BP1 in 21 d diaphragm. These responses were not observed in 2 d or 7 d postnatal diaphragm. Results demonstrate that maternal betamethasone treatment causes postnatal diaphragmatic dysfunction at 21 d PNA, which is attributed to MHC II protein loss and impairment of the anabolic signalling pathway. Developmental modifications in MHC fibre composition and protein signalling account for the age-specific diaphragm dysfunction.

Characterisation of polymers, 1

CERN Document Server

Crompton, Roy

2008-01-01

This essential guide to Polymer Characterisation is a complete compendium of methodologies that have evolved for the determination of the chemical composition of polymers. This 478-page book gives an up-to-date and thorough exposition of the state-of-the-art theories and availability of instrumentation needed to effect chemical and physical analysis of polymers. This is supported by approximately 1200 references. Volume 1 covers the methodology used for the determination of metals, non-metals and organic functional groups in polymers, and for the determination of the ratio in which different m

Anion-conducting polymer, composition, and membrane

Science.gov (United States)

Pivovar, Bryan S [Los Alamos, NM; Thorn, David L [Los Alamos, NM

2009-09-01

Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

Science.gov (United States)

Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

2015-07-21

Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

2017-10-17

Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

Diaphragm Dysfunction in Critical Illness.

Science.gov (United States)

Supinski, Gerald S; Morris, Peter E; Dhar, Sanjay; Callahan, Leigh Ann

2018-04-01

The diaphragm is the major muscle of inspiration, and its function is critical for optimal respiration. Diaphragmatic failure has long been recognized as a major contributor to death in a variety of systemic neuromuscular disorders. More recently, it is increasingly apparent that diaphragm dysfunction is present in a high percentage of critically ill patients and is associated with increased morbidity and mortality. In these patients, diaphragm weakness is thought to develop from disuse secondary to ventilator-induced diaphragm inactivity and as a consequence of the effects of systemic inflammation, including sepsis. This form of critical illness-acquired diaphragm dysfunction impairs the ability of the respiratory pump to compensate for an increased respiratory workload due to lung injury and fluid overload, leading to sustained respiratory failure and death. This review examines the presentation, causes, consequences, diagnosis, and treatment of disorders that result in acquired diaphragm dysfunction during critical illness. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Progressive fracture of polymer matrix composite structures: A new approach

Science.gov (United States)

Chamis, C. C.; Murthy, P. L. N.; Minnetyan, L.

1992-01-01

A new approach independent of stress intensity factors and fracture toughness parameters has been developed and is described for the computational simulation of progressive fracture of polymer matrix composite structures. The damage stages are quantified based on physics via composite mechanics while the degradation of the structural behavior is quantified via the finite element method. The approach account for all types of composite behavior, structures, load conditions, and fracture processes starting from damage initiation, to unstable propagation and to global structural collapse. Results of structural fracture in composite beams, panels, plates, and shells are presented to demonstrate the effectiveness and versatility of this new approach. Parameters and guidelines are identified which can be used as criteria for structural fracture, inspection intervals, and retirement for cause. Generalization to structures made of monolithic metallic materials are outlined and lessons learned in undertaking the development of new approaches, in general, are summarized.

Methods of enhancing conductivity of a polymer-ceramic composite electrolyte

Science.gov (United States)

Kumar, Binod

2003-12-02

Methods for enhancing conductivity of polymer-ceramic composite electrolytes are provided which include forming a polymer-ceramic composite electrolyte film by a melt casting technique and uniaxially stretching the film from about 5 to 15% in length. The polymer-ceramic composite electrolyte is also preferably annealed after stretching such that it has a room temperature conductivity of from 10.sup.-4 S cm.sup.-1 to 10.sup.-3 S cm.sup.-1. The polymer-ceramic composite electrolyte formed by the methods of the present invention may be used in lithium rechargeable batteries.

Fabrication and characterization of a micromachined swirl-shaped ionic polymer metal composite actuator with electrodes exhibiting asymmetric resistance.

Science.gov (United States)

Feng, Guo-Hua; Liu, Kim-Min

2014-05-12

This paper presents a swirl-shaped microfeatured ionic polymer-metal composite (IPMC) actuator. A novel micromachining process was developed to fabricate an array of IPMC actuators on a glass substrate and to ensure that no shortcircuits occur between the electrodes of the actuator. We demonstrated a microfluidic scheme in which surface tension was used to construct swirl-shaped planar IPMC devices of microfeature size and investigated the flow velocity of Nafion solutions, which formed the backbone polymer of the actuator, within the microchannel. The unique fabrication process yielded top and bottom electrodes that exhibited asymmetric surface resistance. A tool for measuring surface resistance was developed and used to characterize the resistances of the electrodes for the fabricated IPMC device. The actuator, which featured asymmetric electrode resistance, caused a nonzero-bias current when the device was driven using a zero-bias square wave, and we propose a circuit model to describe this phenomenon. Moreover, we discovered and characterized a bending and rotating motion when the IPMC actuator was driven using a square wave. We observed a strain rate of 14.6% and a displacement of 700 μm in the direction perpendicular to the electrode surfaces during 4.5-V actuation.

Interfacial delamination in polymer coated metal sheet : a numerical-experimental study

NARCIS (Netherlands)

van den Bosch, M.

2007-01-01

An increasing amount of products are nowadays made of polymer coated metal sheet. Polymer coated metal has several advantages compared to traditionally Sn (tin) coated metal, such as costs savings and a more environmental friendly production process. Beverage and food cans are formed by draw-redraw

The influence of heavy metals on the production of extracellular polymer substances in the processes of heavy metal ions elimination.

Science.gov (United States)

Mikes, J; Siglova, M; Cejkova, A; Masak, J; Jirku, V

2005-01-01

Wastewaters from a chemical industry polluted by heavy metal ions represent a hazard for all living organisms. It can mean danger for ecosystems and human health. New methods are sought alternative to traditional chemical and physical processes. Active elimination process of heavy metals ions provided by living cells, their components and extracellular products represents a potential way of separating toxic heavy metals from industrial wastewaters. While the abilities of bacteria to remove metal ions in solution are extensively used, fungi have been recognized as a promising kind of low-cost adsorbents for removal of heavy-metal ions from aqueous waste sources. Yeasts and fungi differ from each other in their constitution and in their abilities to produce variety of extracellular polymeric substances (EPS) with different mechanisms of metal interactions. The accumulation of Cd(2+), Cr(6+), Pb(2+), Ni(2+) and Zn(2+) by yeasts and their EPS was screened at twelve different yeast species in microcultivation system Bioscreen C and in the shaking Erlenmayer's flasks. This results were compared with the production of yeast EPS and the composition of yeast cell walls. The EPS production was measured during the yeast growth and cell wall composition was studied during the cultivations in the shaking flasks. At the end of the process extracellular polymers and their chemical composition were isolated and amount of bound heavy metals was characterized. The variable composition and the amount of the EPS were found at various yeast strains. It was influenced by various compositions of growth medium and also by various concentrations of heavy metals. It is evident, that the amount of bound heavy metals was different. The work reviews the possibilities of usage of various yeast EPS and components of cell walls in the elimination processes of heavy metal ions. Further the structure and properties of yeasts cell wall and EPS were discussed. The finding of mechanisms mentioned

Polymer Composites Corrosive Degradation: A Computational Simulation

Science.gov (United States)

Chamis, Christos C.; Minnetyan, Levon

2007-01-01

A computational simulation of polymer composites corrosive durability is presented. The corrosive environment is assumed to manage the polymer composite degradation on a ply-by-ply basis. The degradation is correlated with a measured pH factor and is represented by voids, temperature and moisture which vary parabolically for voids and linearly for temperature and moisture through the laminate thickness. The simulation is performed by a computational composite mechanics computer code which includes micro, macro, combined stress failure and laminate theories. This accounts for starting the simulation from constitutive material properties and up to the laminate scale which exposes the laminate to the corrosive environment. Results obtained for one laminate indicate that the ply-by-ply degradation degrades the laminate to the last one or the last several plies. Results also demonstrate that the simulation is applicable to other polymer composite systems as well.

Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

KAUST Repository

Srivastava, Samanvaya

2012-04-17

Phase behavior of poly(ethylene glycol) (PEG) tethered silica nanoparticles dispersed in PEG hosts is investigated using small-angle X-ray scattering. Phase separation in dispersions of densely grafted nanoparticles is found to display strikingly different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer composites incorporating results from this as well as various other contemporary studies is presented. We show that in the range of moderate to high grafting densities the dispersion state of nanoparticles in composites is largely insensitive to the grafting density of the tethered chains and chemistry of the polymer host. Instead, the ratio of the particle diameter to the size of the tethered chain and the ratio of the molecular weights of the host and tethered polymer chains (P/N) are shown to play a dominant role. Additionally, we find that well-functionalized nanoparticles form stable dispersions in their polymer host beyond the P/N limit that demarcates the wetting/dewetting transition in polymer brushes on flat substrates interacting with polymer melts. A general strategy for achieving uniform nanoparticle dispersion in polymers is proposed. © 2012 American Chemical Society.

Design and Fabrication of a Large-Stroke Deformable Mirror Using a Gear-Shape Ionic-Conductive Polymer Metal Composite

Directory of Open Access Journals (Sweden)

Guo-Dung John Su

2012-08-01

Full Text Available Conventional camera modules with image sensors manipulate the focus or zoom by moving lenses. Although motors, such as voice-coil motors, can move the lens sets precisely, large volume, high power consumption, and long moving time are critical issues for motor-type camera modules. A deformable mirror (DM provides a good opportunity to improve these issues. The DM is a reflective type optical component which can alter the optical power to focus the lights on the two dimensional optical image sensors. It can make the camera system operate rapidly. Ionic polymer metal composite (IPMC is a promising electro-actuated polymer material that can be used in micromachining devices because of its large deformation with low actuation voltage. We developed a convenient simulation model based on Young’s modulus and Poisson’s ratio. We divided an ion exchange polymer, also known as Nafion^®, into two virtual layers in the simulation model: one was expansive and the other was contractive, caused by opposite constant surface forces on each surface of the elements. Therefore, the deformation for different IPMC shapes can be described more easily. A standard experiment of voltage vs. tip displacement was used to verify the proposed modeling. Finally, a gear shaped IPMC actuator was designed and tested. Optical power of the IPMC deformable mirror is experimentally demonstrated to be 17 diopters with two volts. The needed voltage was about two orders lower than conventional silicon deformable mirrors and about one order lower than the liquid lens.

21 CFR 888.3565 - Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellofemorotibial metal/polymer... Devices § 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. (a) Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis is a device...

Evaluation of circuit models for an IPMC (ionic polymer-metal composite) sensor using a parameter estimate method

International Nuclear Information System (INIS)

Park, Kiwon; Lee, Hyungki

2012-01-01

The present study investigated a sensor system to effectively detect the bending angles applied on an ionic polymer metal composite sensor. Firstly, the amount of net charge produced by the motion of cations was correlated to the bending angle based on the geometric relationship between a flat and a bent IPMC, and the relationship was represented by linear and nonlinear polynomial equations. Secondly, several existing and modified R and C circuit models with a linear charge model were evaluated using the experimental data. Thirdly, the nonlinear charge model was applied to a selected circuit model, and the effectivenesses of the linear and the nonlinear charge models were compared. Finally, the sensor output signal was fed into the inverse model of the identified circuit model to reproduce the bending angles. This paper presents a simple data processing procedure using the inverse transfer function of a selected circuit model that successfully monitored various bending motions of an IPMC sensor.

21 CFR 888.3530 - Knee joint femorotibial metal/polymer semi-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femorotibial metal/polymer semi... § 888.3530 Knee joint femorotibial metal/polymer semi-constrained cemented prosthesis. (a) Identification. A knee joint femorotibial metal/polymer semi-constrained cemented prosthesis is a device intended...

21 CFR 888.3540 - Knee joint patellofemoral polymer/metal semi-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellofemoral polymer/metal semi... § 888.3540 Knee joint patellofemoral polymer/metal semi-constrained cemented prosthesis. (a) Identification. A knee joint patellofemoral polymer/metal semi-constrained cemented prosthesis is a two-part...

21 CFR 888.3520 - Knee joint femorotibial metal/polymer non-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femorotibial metal/polymer non... § 888.3520 Knee joint femorotibial metal/polymer non-constrained cemented prosthesis. (a) Identification. A knee joint femorotibial metal/polymer non-constrained cemented prosthesis is a device intended to...

Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Composites

Science.gov (United States)

Kang, Jin Ho; Cano, Roberto J.; Ratcliffe, James G.; Luong, Hoa; Grimsley, Brian W.; Siochi, Emilie J.

2016-01-01

For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strengthand stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Despite several attempts to solve these issues with the addition of carbon nanotubes (CNT) into polymer matrices, and/or by interleaving CNT sheets between conventional carbon fiber (CF) composite layers, there are still interfacial problems that exist between CNTs (or CF) and the resin. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing (double cantilever beam and end-notched flexure test). Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated. Interleaving CNT sheets significantly improved the in-plane (axial and perpendicular direction of CF alignment) thermal conductivity of the hybrid composite laminates by 50 - 400%.

Characterization of the harvesting capabilities of an ionic polymer metal composite device

Science.gov (United States)

Brufau-Penella, J.; Puig-Vidal, M.; Giannone, P.; Graziani, S.; Strazzeri, S.

2008-02-01

Harvesting systems capable of transforming dusty environmental energy into electrical energy have aroused considerable interest in the last two decades. Several research works have focused on the transformation of mechanical environmental vibrations into electrical energy. Most of the research activity refers to classic piezoelectric ceramic materials, but more recently piezoelectric polymer materials have been considered. In this paper, a novel point of view regarding harvesting systems is proposed: using ionic polymer metal composites (IPMCs) as generating materials. The goal of this paper is the development of a model able to predict the energy harvesting capabilities of an IPMC material working in air. The model is developed by using the vibration transmission theory of an Euler-Bernoulli cantilever IPMC beam. The IPMC is considered to work in its linear elastic region with a viscous damping contribution ranging from 0.1 to 100 Hz. An identification process based on experimental measurements performed on a Nafion® 117 membrane is used to estimate the material parameters. The model validation shows a good agreement between simulated and experimental results. The model is used to predict the optimal working region and the optimal geometrical parameters for the maximum power generation capacity of a specific membrane. The model takes into account two restrictions. The first is due to the beam theory, which imposes a maximum ratio of 0.5 between the cantilever width and length. The second restriction is to force the cantilever to oscillate with a specific strain; in this paper a 0.3% strain is considered. By considering these two assumptions as constraints on the model, it is seen that IPMC materials could be used as low-power generators in a low-frequency region. The optimal dimensions for the Nafion® 117 membrane are length = 12 cm and width = 6.2 cm, and the electric power generation is 3 nW at a vibrating frequency of 7.09 rad s-1. IPMC materials can sustain

Thermal Protective Coating for High Temperature Polymer Composites

Science.gov (United States)

Barron, Andrew R.

1999-01-01

The central theme of this research is the application of carboxylate-alumoxane nanoparticles as precursors to thermally protective coatings for high temperature polymer composites. In addition, we will investigate the application of carboxylate-alumoxane nanoparticle as a component to polymer composites. The objective of this research was the high temperature protection of polymer composites via novel chemistry. The significance of this research is the development of a low cost and highly flexible synthetic methodology, with a compatible processing technique, for the fabrication of high temperature polymer composites. We proposed to accomplish this broad goal through the use of a class of ceramic precursor material, alumoxanes. Alumoxanes are nano-particles with a boehmite-like structure and an organic periphery. The technical goals of this program are to prepare and evaluate water soluble carboxylate-alumoxane for the preparation of ceramic coatings on polymer substrates. Our proposed approach is attractive since proof of concept has been demonstrated under the NRA 96-LeRC-1 Technology for Advanced High Temperature Gas Turbine Engines, HITEMP Program. For example, carbon and Kevlar(tm) fibers and matting have been successfully coated with ceramic thermally protective layers.

Radial-Electric-Field Piezoelectric Diaphragm Pumps

Science.gov (United States)

Bryant, Robert G.; Working, Dennis C.; Mossi, Karla; Castro, Nicholas D.; Mane, Pooma

2009-01-01

In a recently invented class of piezoelectric diaphragm pumps, the electrode patterns on the piezoelectric diaphragms are configured so that the electric fields in the diaphragms have symmetrical radial (along-the-surface) components in addition to through-the-thickness components. Previously, it was accepted in the piezoelectric-transducer art that in order to produce the out-of-plane bending displacement of a diaphragm needed for pumping, one must make the electric field asymmetrical through the thickness, typically by means of electrodes placed on only one side of the piezoelectric material. In the present invention, electrodes are placed on both sides and patterned so as to produce substantial radial as well as through-the-thickness components. Moreover, unlike in the prior art, the electric field can be symmetrical through the thickness. Tests have shown in a given diaphragm that an electrode configuration according to this invention produces more displacement than does a conventional one-sided electrode pattern. The invention admits of numerous variations characterized by various degrees of complexity. Figure 1 is a simplified depiction of a basic version. As in other piezoelectric diaphragm pumps of similar basic design, the prime mover is a piezoelectric diaphragm. Application of a suitable voltage to the electrodes on the diaphragm causes it to undergo out-of-plane bending. The bending displacement pushes a fluid out of, or pulls the fluid into, a chamber bounded partly by the diaphragm. Also as in other diaphragm pumps in general, check valves ensure that the fluid flows only in through one port and only out through another port.

Large Dielectric Constant Enhancement in MXene Percolative Polymer Composites

KAUST Repository

Tu, Shao Bo

2018-04-06

near the percolation limit of about 15.0 wt % MXene loading, which surpasses all previously reported composites made of carbon-based fillers in the same polymer. With up to 10 wt % MXene loading, the dielectric loss of the MXene/P(VDF-TrFE-CFE) composite indicates only an approximately 5-fold increase (from 0.06 to 0.35), while the dielectric constant increased by 25 times over the same composition range. Furthermore, the ratio of permittivity to loss factor of the MXene-polymer composite is superior to that of all previously reported fillers in this same polymer. The dielectric constant enhancement effect is demonstrated to exist in other polymers as well when loaded with MXene. We show that the dielectric constant enhancement is largely due to the charge accumulation caused by the formation of microscopic dipoles at the surfaces between the MXene sheets and the polymer matrix under an external applied electric field.

Application of Composite Polymer Electrolytes

National Research Council Canada - National Science Library

Scrosati, Bruno

2001-01-01

...)PEO-based composite polymer electrolytes, by a series of specifically addressed electrochemical tests which included the determination of the conductivity and of the lithium transference number...

Electrospun Polyaniline-Based Composite Nanofibers: Tuning the Electrical Conductivity by Tailoring the Structure of Thiol-Protected Metal Nanoparticles

Directory of Open Access Journals (Sweden)

Filippo Pierini

2017-01-01

Full Text Available Composite nanofibers made of a polyaniline-based polymer blend and different thiol-capped metal nanoparticles were prepared using ex situ synthesis and electrospinning technique. The effects of the nanoparticle composition and chemical structure on the electrical properties of the nanocomposites were investigated. This study confirmed that Brust’s procedure is an effective method for the synthesis of sub-10 nm silver, gold, and silver-gold alloy nanoparticles protected with different types of thiols. Electron microscopy results demonstrated that electrospinning is a valuable technique for the production of composite nanofibers with similar morphology and revealed that nanofillers are well-dispersed into the polymer matrix. X-ray diffraction tests proved the lack of a significant influence of the nanoparticle chemical structure on the polyaniline chain arrangement. However, the introduction of conductive nanofillers in the polymer matrix influences the charge transport noticeably improving electrical conductivity. The enhancement of electrical properties is mediated by the nanoparticle capping layer structure. The metal nanoparticle core composition is a key parameter, which exerted a significant influence on the conductivity of the nanocomposites. These results prove that the proposed method can be used to tune the electrical properties of nanocomposites.

Modelling anisotropic water transport in polymer composite ...

Indian Academy of Sciences (India)

Parameters for Fickian diffusion and polymer relaxation models were determined by .... Water transport process of resin and polymer composite specimens at ..... simulation. ... Kwon Y W and Bang H 1997 Finite element method using matlab.

Polymer-noble metal nanocomposites: Review

CSIR Research Space (South Africa)

Folarin, OM

2011-09-01

Full Text Available because of their multi-functionality, ease of process-ability, potential for large-scale manufacturing, significantly lighter than metals, ease of synthesis when compared to the oxide/noble metal multi-layers (Gass et al., 2006; Lee et al., 2003.... their easy aggregation arising from their high surface free energy (Lee et al., 2006). In the design of nanocomposites, one must consider the properties of the polymer matrix as well as the stability of the nanoparticles and more importantly...

A new material for chemical industry - wood polymer composites

International Nuclear Information System (INIS)

Majali, A.B.; Patil, N.D.

1979-01-01

The paper outlines the advantages of the radiation cured wood-polymer composites (WPC) for application in certain critical areas of chemical industry. The wood-polymer composite made filterpress frames and plates were tested in a chemical plant. The entire exercise is elaborated. The radiation cured wood exhibited a considerably extended useful life in alkaline and acidic solutions. Composites based on teak wood showed a remarkable improvement with a nominal polymer loading of 10%. The reports of accelerated aging test of WPC are also presented. (auth.)

3D optical printing of piezoelectric nanoparticle-polymer composite materials.

Science.gov (United States)

Kim, Kanguk; Zhu, Wei; Qu, Xin; Aaronson, Chase; McCall, William R; Chen, Shaochen; Sirbuly, Donald J

2014-10-28

Here we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be optically printed into three-dimensional (3D) microstructures using digital projection printing. Piezoelectric polymers were fabricated by incorporating barium titanate (BaTiO3, BTO) nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate and exposing to digital optical masks that could be dynamically altered to generate user-defined 3D microstructures. To enhance the mechanical-to-electrical conversion efficiency of the composites, the BTO nanoparticles were chemically modified with acrylate surface groups, which formed direct covalent linkages with the polymer matrix under light exposure. The composites with a 10% mass loading of the chemically modified BTO nanoparticles showed piezoelectric coefficients (d(33)) of ∼ 40 pC/N, which were over 10 times larger than composites synthesized with unmodified BTO nanoparticles and over 2 times larger than composites containing unmodified BTO nanoparticles and carbon nanotubes to boost mechanical stress transfer efficiencies. These results not only provide a tool for fabricating 3D piezoelectric polymers but lay the groundwork for creating highly efficient piezoelectric polymer materials via nanointerfacial tuning.

Phase stability and dynamics of entangled polymer-nanoparticle composites.

KAUST Repository

Mangal, Rahul

2015-06-05

Nanoparticle-polymer composites, or polymer-nanoparticle composites (PNCs), exhibit unusual mechanical and dynamical features when the particle size approaches the random coil dimensions of the host polymer. Here, we harness favourable enthalpic interactions between particle-tethered and free, host polymer chains to create model PNCs, in which spherical nanoparticles are uniformly dispersed in high molecular weight entangled polymers. Investigation of the mechanical properties of these model PNCs reveals that the nanoparticles have profound effects on the host polymer motions on all timescales. On short timescales, nanoparticles slow-down local dynamics of the host polymer segments and lower the glass transition temperature. On intermediate timescales, where polymer chain motion is typically constrained by entanglements with surrounding molecules, nanoparticles provide additional constraints, which lead to an early onset of entangled polymer dynamics. Finally, on long timescales, nanoparticles produce an apparent speeding up of relaxation of their polymer host.

Phase stability and dynamics of entangled polymer-nanoparticle composites.

KAUST Repository

Mangal, Rahul; Srivastava, Samanvaya; Archer, Lynden A

2015-01-01

Nanoparticle-polymer composites, or polymer-nanoparticle composites (PNCs), exhibit unusual mechanical and dynamical features when the particle size approaches the random coil dimensions of the host polymer. Here, we harness favourable enthalpic interactions between particle-tethered and free, host polymer chains to create model PNCs, in which spherical nanoparticles are uniformly dispersed in high molecular weight entangled polymers. Investigation of the mechanical properties of these model PNCs reveals that the nanoparticles have profound effects on the host polymer motions on all timescales. On short timescales, nanoparticles slow-down local dynamics of the host polymer segments and lower the glass transition temperature. On intermediate timescales, where polymer chain motion is typically constrained by entanglements with surrounding molecules, nanoparticles provide additional constraints, which lead to an early onset of entangled polymer dynamics. Finally, on long timescales, nanoparticles produce an apparent speeding up of relaxation of their polymer host.

Bamboo reinforced polymer composite - A comprehensive review

Science.gov (United States)

Roslan, S. A. H.; Rasid, Z. A.; Hassan, M. Z.

2018-04-01

Bamboo has greatly attention of researchers due to their advantages over synthetic polymers. It is entirely renewable, environmentally-friendly, non-toxic, cheap, non-abrasive and fully biodegradable. This review paper summarized an oveview of the bamboo, fiber extraction and mechanical behavior of bamboo reinforced composites. A number of studies proved that mechanical properties of bamboo fibers reinforced reinforced polymer composites are excellent and competent to be utilized in high-tech applications. The properties of the laminate are influenced by the fiber loading, fibre orientation, physical and interlaminar adhesion between fibre and matrix. In contrast, the presence of chemical constituents such as cellulose, lignin, hemicellulose and wax substances in natural fibres preventing them from firmly binding with polymer resin. Thus, led to poor mechanical properties for composites. Many attempt has been made in order to overcome this issue by using the chemical treatment.

APPLICATION OF ADDITIVELY MANUFACTURED POLYMER COMPOSITE PROTOTYPES IN FOUNDRY

Directory of Open Access Journals (Sweden)

Wiesław Kuczko

2015-05-01

Full Text Available The paper presents a method, developed by the authors, for manufacturing polymer composites with the matrix manufactured in a layered manner (via 3D printing – Fused Deposition Modeling out of a thermoplastic material. As an example of practical application of this method, functional prototypes are presented, which were used as elements of foundry tooling – patterns for sand molding. In case of manufacturing prototype castings or short series of products, foundries usually cooperate with modeling studios, which produce patterns by conventional, subtractive manufacturing technologies. If patterns have complex shapes, this results in high manufacturing costs and significantly longer time of tooling preparation. The method proposed by the authors allows manufacturing functional prototypes in a short time thanks to utilizing capabilities of additive manufacturing (3D printing technology. Thanks to using two types of materials simultaneously (ABS combined with chemically hardened resins, the produced prototypes are capable of carrying increased loads. Moreover, the method developed by the authors is characterized by manufacturing costs lower than in the basic technology of Fused Deposition Modeling. During the presented studies, the pattern was produced as a polymer composite and it was used to prepare a mold and a set of metal castings.

Nanostructured metal-polyaniline composites

Science.gov (United States)

Wang, Hsing-Lin; Li, Wenguang; Bailey, James A.; Gao, Yuan

2010-08-31

Metal-polyaniline (PANI) composites are provided together with a process of preparing such composites by an electrodeless process. The metal of the composite can have nanoscale structural features and the composites can be used in applications such as catalysis for hydrogenation reactions and for analytical detection methods employing SERS.

Gas Phase Sensing of Alcohols by Metal Organic Framework-Polymer Composite Materials

NARCIS (Netherlands)

Sachdeva, S.; Koper, S.J.H.; Sabetghadam Esfahani, A.; Soccol, Dimitri; Gravesteijn, Dirk J.; Kapteijn, F.; Sudholter, E.J.R.; Gascon Sabate, J.; de Smet, L.C.P.M.

2017-01-01

Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH₂-MIL-53(Al)

Gas Phase Sensing of Alcohols by Metal Organic Framework-Polymer Composite Materials

NARCIS (Netherlands)

Sachdeva, Sumit; Koper, Sander J.H.; Sabetghadam, Anahid; Soccol, Dimitri; Gravesteijn, Dirk J.; Kapteijn, Freek; Sudhölter, Ernst J.R.; Gascon, Jorge; Smet, De Louis C.P.M.

2017-01-01

Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH2-MIL-53(Al) were dispersed in

Flexible ITO-Free Polymer Solar Cells

DEFF Research Database (Denmark)

Angmo, Dechan; Krebs, Frederik C

2013-01-01

Indium tin oxide (ITO) is the material-of-choice for transparent conductors in any optoelectronic application. However, scarce resources of indium and high market demand of ITO have created large price fluctuations and future supply concerns. In polymer solar cells (PSCs), ITO is the single......-cost alternatives to ITO suitable for use in PSCs. These alternatives belong to four material groups: polymers; metal and polymer composites; metal nanowires and ultra-thin metal films; and carbon nanotubes and graphene. We further present the progress of employing these alternatives in PSCs and identify future...

Understanding the Thermal Properties of Precursor-Ionomers to Optimize Fabrication Processes for Ionic Polymer-Metal Composites (IPMCs

Directory of Open Access Journals (Sweden)

Sarah Trabia

2018-04-01

Full Text Available Ionic polymer-metal composites (IPMCs are one of many smart materials and have ionomer bases with a noble metal plated on the surface. The ionomer is usually Nafion, but recently Aquivion has been shown to be a promising alternative. Ionomers are available in the form of precursor pellets. This is an un-activated form that is able to melt, unlike the activated form. However, there is little study on the thermal characteristics of these precursor ionomers. This lack of knowledge causes issues when trying to fabricate ionomer shapes using methods such as extrusion, hot-pressing, and more recently, injection molding and 3D printing. To understand the two precursor-ionomers, a set of tests were conducted to measure the thermal degradation temperature, viscosity, melting temperature, and glass transition. The results have shown that the precursor Aquivion has a higher melting temperature (240 °C than precursor Nafion (200 °C and a larger glass transition range (32–65°C compared with 21–45 °C. The two have the same thermal degradation temperature (~400 °C. Precursor Aquivion is more viscous than precursor Nafion as temperature increases. Based on the results gathered, it seems that the precursor Aquivion is more stable as temperature increases, facilitating the manufacturing processes. This paper presents the data collected to assist researchers in thermal-based fabrication processes.

A review of mechanical and tribological behaviour of polymer composite materials

Science.gov (United States)

Prabhakar, K.; Debnath, S.; Ganesan, R.; Palanikumar, K.

2018-04-01

Composite materials are finding increased applications in many industrial applications. A nano-composite is a matrix to which nanosized particles have been incorporated to drastically improve the mechanical performance of the original material. The structural components produced using nano-composites will exhibit a high strength-to-weight ratio. The properties of nano-composites have caused researchers and industries to consider using this material in several fields. Polymer nanocomposites consists of a polymer material having nano-particles or nano-fillers dispersed in the polymer matrix which may be of different shapes with at least one of the dimensions less than 100nm. In this paper, comprehensive review of polymer nanocomposites was done majorly in three different areas. First, mechanical behaviour of polymer nanocomposites which focuses on the mechanical property evaluation such as tensile strength, impact strength and modulus of elasticity based on the different combination of filler materials and nanoparticle inclusion. Second, wear behavior of Polymer composite materials with respect to different impingement angles and variation of filler composition using different processing techniques. Third, tribological (Friction and Wear) behaviour of nanocomposites using various combination of nanoparticle inclusion and time. Finally, it summarized the challenges and prospects of polymer nanocomposites.

Manufacturing of ionic polymer-metal composites (IPMCs) that can actuate into complex curves

Science.gov (United States)

Stoimenov, Boyko L.; Rossiter, Jonathan M.; Mukai, Toshiharu

2007-04-01

Ionic polymer-metal composites (IPMC) are soft actuators with potential applications in the fields of medicine and biologically inspired robotics. Typically, an IPMC bends with approximately constant curvature when voltage is applied to it. More complex shapes were achieved in the past by pre-shaping the actuator or by segmentation and separate actuation of each segment. There are many applications for which fully independent control of each segment of the IPMC is not required and the use of external wiring is objectionable. In this paper we propose two key elements needed to create an IPMC, which can actuate into a complex curve. The first is a connection between adjacent segments, which enables opposite curvature. This can be achieved by reversing the polarity applied on each side of the IPMC, for example by a through-hole connection. The second key element is a variable curvature segment. The segment is designed to bend with any fraction of its full bending ability under given electrical input by changing the overlap of opposite charge electrodes. We demonstrated the usefulness of these key elements in two devices. One is a bi-stable buckled IPMC beam, also used as a building block in a linear actuator device. The other one is an IPMC, actuating into an S-shaped curve with gradually increasing curvature near the ends. The proposed method of manufacturing holds promise for a wide range of new applications of IPMCs, including applications in which IPMCs are used for sensing.

Self-Sensing Control of Nafion-Based Ionic Polymer-Metal Composite (IPMC Actuator in the Extremely Low Humidity Environment

Directory of Open Access Journals (Sweden)

Minoru Sasaki

2013-10-01

Full Text Available This paper presents feedforward, feedback and two-degree-of-freedom control applied to an Ionic Polymer-Metal Composite (IPMC actuator. It presents a high potential for development of miniature robots and biomedical devices and artificial muscles. We have reported in the last few years that dehydration treatment improves the electrical controllability of bending in Selemion CMV-based IPMCs. We tried to replicate this controllability in Nafion-based IPMC. We found that the displacement of a Nafion-based IPMC was proportional to the total charge imposed, just as in the Selemion-CMV case. This property is the basis of self-sensing controllers for Nafion-based IPMC bending behavior: we perform bending curvature experiments on Nafion-based IPMCs, obtaining the actuator's dynamics and transfer function. From these, we implemented self-sensing controllers using feedforward, feedback and two-degree-of-freedom techniques. All three controllers performed very well with the Nafion-based IPMC actuator.

Hybrid polymer-inorganic photovoltaic cells

NARCIS (Netherlands)

Beek, W.J.E.; Janssen, R.A.J.; Merhari, L.

2009-01-01

Composite materials made from organic conjugated polymers and inorganic semiconductors such as metal oxides attract considerable interest for photovoltaic applications. Hybrid polymer-inorganic solar cells offer the opportunity to combine the beneficial properties of the two materials in charge

Electro-optics of novel polymer-liquid crystalline composites

International Nuclear Information System (INIS)

Ibragimov, T.D.; Bayramov, G.M.; Imamaliyev, A.R.; Bayramov, G.M.

2014-01-01

The polymer network liquid crystals based on the liquid crystals H37 and 5CB with PMVP and PEG have been developed. Mesogene substance HOBA is served for stabilization of obtaining composites. Kinetics of network formation is investigated by methods of polarization microscopy and integrated small-angle scattering. It is shown that gel-like states of the composite H-37+PMVP+HOBA and 5CB+PEG+HOBA are formed at polymer concentration above 7 percent and 9 percent, correspondingly. The basic electro-optic parameters of the obtained composites are determined at room temperature. Experimental results are explained by phase separation of the system, diminution of a working area of electro-optical effects and influence of areas with high polymer concentration on areas with their low concentration

The critical particle size for enhancing thermal conductivity in metal nanoparticle-polymer composites

Science.gov (United States)

Lu, Zexi; Wang, Yan; Ruan, Xiulin

2018-02-01

Polymers used as thermal interface materials are often filled with high-thermal conductivity particles to enhance the thermal performance. Here, we have combined molecular dynamics and the two-temperature model in 1D to investigate the impact of the metal filler size on the overall thermal conductivity. A critical particle size has been identified above which thermal conductivity enhancement can be achieved, caused by the interplay between high particle thermal conductivity and the added electron-phonon and phonon-phonon thermal boundary resistance brought by the particle fillers. Calculations on the SAM/Au/SAM (self-assembly-monolayer) system show a critical thickness Lc of around 10.8 nm. Based on the results, we define an effective thermal conductivity and propose a new thermal circuit analysis approach for the sandwiched metal layer that can intuitively explain simulation and experimental data. The results show that when the metal layer thickness decreases to be much smaller than the electron-phonon cooling length (or as the "thin limit"), the effective thermal conductivity is just the phonon portion, and electrons do not participate in thermal transport. As the thickness increases to the "thick limit," the effective thermal conductivity recovers the metal bulk value. Several factors that could affect Lc are discussed, and it is discovered that the thermal conductivity, thermal boundary resistance, and the electron-phonon coupling factor are all important in controlling Lc.

Adhesion along metal-polymer interfaces during plastic deformation

NARCIS (Netherlands)

van Tijum, R.; Vellinga, W. P.; De Hosson, J. Th. M.

In this paper a numerical study is presented that concentrates on the influence of the interface roughness that develops during plastic deformation of a metal, on the work of adhesion and on the change of interface energy upon contact with a glassy polymer. The polymer coating is described with a

Estimation of strength parameters of small-bore metal-polymer pipes

Science.gov (United States)

Shaydakov, V. V.; Chernova, K. V.; Penzin, A. V.

2018-03-01

The paper presents results from a set of laboratory studies of strength parameters of small-bore metal-polymer pipes of type TG-5/15. A wave method was used to estimate the provisional modulus of elasticity of the metal-polymer material of the pipes. Longitudinal deformation, transverse deformation and leak-off pressure were determined experimentally, with considerations for mechanical damage and pipe bend.

On the mechanical behaviours of a craze in particulate-polymer composites

Science.gov (United States)

Zhang, Y. M.; Zhang, W. G.; Fan, M.; Xiao, Z. M.

2018-05-01

In polymeric composites, well-defined inclusions are incorporated into the polymer matrix to alleviate the brittleness of polymers. When a craze is initiated in such a composite, the interaction between the craze and the surrounding inclusions will greatly affect the composite's mechanical behaviours and toughness. To the best knowledge of the authors, only little research work has been found so far on the interaction between a craze and the near-by inclusions in particulate-polymer composites. In the current study, the first time, the influences of the surrounding inclusions on the craze are investigated in particulate-polymer composites. The three-phase model is adopted to study the fracture behaviours of the craze affected by multiple inclusions. An iterative procedure is proposed to solve the stress intensity factors. Parametric studies are performed to investigate the influences of the reinforcing particle volume fraction and the shear modulus ratio on fracture behaviours of particulate-polymer composites.

Metallic microwires obtained as replicas of etched ion tracks in polymer matrixes: Microscopy and emission properties

International Nuclear Information System (INIS)

Zagorski, D.L.; Bedin, S.A.; Oleinikov, V.A.; Polyakov, N.B.; Rybalko, O.G.; Mchedlishvili, B.V.

2009-01-01

Specially prepared porous matrixes (with through and dead-end pores of cylindrical or conical forms) were used as the templates for making ensembles of microwires. The process of electrodeposition of metal (Cu) into these pores was investigated. AFM technique was used for studying the 'composite material' (metal microwires embedded into the polymer matrix). It was shown that the combination of different modes of AFM (tapping with phase-contrast mode, contact with lateral force mode) makes it possible to detect metal in the polymer matrix. Additional spread resistance mode in the contact regime allowed to measure the electrical conductivity of a single wire. The ensembles of free-standing microwires (metallic replicas of the pores obtained after removing of the polymer matrix) were used as the substrates (for deposition of the probe) for ion emission in the mass-spectrometer. It was shown that the intensity of formed ion beam increases with increasing of power of the laser pulse and with increasing of the mass of the probe. The intensity of mass-spectra signal on the power of laser pulse has a threshold character with saturation accompanied with the appearance of dimer ions. At the same time this intensity decreases with the increasing of the surface density of wires. The effect of degradation of wires during the laser pulse irradiation was found.

Self-healing in single and multiple fiber(s reinforced polymer composites

Directory of Open Access Journals (Sweden)

Woldesenbet E.

2010-06-01

Full Text Available You Polymer composites have been attractive medium to introduce the autonomic healing concept into modern day engineering materials. To date, there has been significant research in self-healing polymeric materials including several studies specifically in fiber reinforced polymers. Even though several methods have been suggested in autonomic healing materials, the concept of repair by bleeding of enclosed functional agents has garnered wide attention by the scientific community. A self-healing fiber reinforced polymer composite has been developed. Tensile tests are carried out on specimens that are fabricated by using the following components: hollow and solid glass fibers, healing agent, catalysts, multi-walled carbon nanotubes, and a polymer resin matrix. The test results have demonstrated that single fiber polymer composites and multiple fiber reinforced polymer matrix composites with healing agents and catalysts have provided 90.7% and 76.55% restoration of the original tensile strength, respectively. Incorporation of functionalized multi-walled carbon nanotubes in the healing medium of the single fiber polymer composite has provided additional efficiency. Healing is found to be localized, allowing multiple healing in the presence of several cracks.

Investigating accidents involving aircraft manufactured from polymer composite materials

Science.gov (United States)

Dunn, Leigh

This study looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. As the use of composite materials in aircraft construction increases, the understanding of how macroscopic failure characteristics of composite materials may aid the field investigator is becoming of increasing importance.. The first phase of this research project was to explore how investigation practitioners conduct wreckage examinations. Four accident investigation case studies were examined. The analysis of the case studies provided a framework of the wreckage examination process. Subsequently, a literature survey was conducted to establish the current level of knowledge on the visual and macroscopic interpretation of polymer composite failures. Relevant literature was identified and a compendium of visual and macroscopic characteristics was created. Two full-scale polymer composite wing structures were loaded statically, in an upward bending direction, until each wing structure fractured and separated. The wing structures were subsequently examined for the existence of failure characteristics. The examination revealed that whilst characteristics were present, the fragmentation of the structure destroyed valuable evidence. A hypothetical accident scenario utilising the fractured wing structures was developed, which UK government accident investigators subsequently investigated. This provided refinement to the investigative framework and suggested further guidance on the interpretation of polymer composite failures by accident investigators..

Fabrication of an Electrically-Resistive, Varistor-Polymer Composite

Directory of Open Access Journals (Sweden)

Sanaz A. Mohammadi

2012-11-01

Full Text Available This study focuses on the fabrication and electrical characterization of a polymer composite based on nano-sized varistor powder. The polymer composite was fabricated by the melt-blending method. The developed nano-composite was characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, field emission scanning electron microscopy (FeSEM, and energy-dispersive X-ray spectroscopy (EDAX. The XRD pattern revealed the crystallinity of the composite. The XRD study also showed the presence of secondary phases due to the substitution of zinc by other cations, such as bismuth and manganese. The TEM picture of the sample revealed the distribution of the spherical, nano-sized, filler particles throughout the matrix, which were in the 10–50 nm range with an average of approximately 11 nm. The presence of a bismuth-rich phase and a ZnO matrix phase in the ZnO-based varistor powder was confirmed by FeSEM images and EDX spectra. From the current-voltage curves, the non-linear coefficient of the varistor polymer composite with 70 wt% of nano filler was 3.57, and its electrical resistivity after the onset point was 861 KΩ. The non-linear coefficient was 1.11 in the sample with 100 wt% polymer content. Thus, it was concluded that the composites established a better electrical non-linearity at higher filler amounts due to the nano-metric structure and closer particle linkages.

Self-Healing Composite of Thermoset Polymer and Programmed Super Contraction Fibers

Science.gov (United States)

Li, Guoqiang (Inventor); Meng, Harper (Inventor)

2016-01-01

A composition comprising thermoset polymer, shape memory polymer to facilitate macro scale damage closure, and a thermoplastic polymer for molecular scale healing is disclosed; the composition has the ability to resolve structural defects by a bio-mimetic close-then heal process. In use, the shape memory polymer serves to bring surfaces of a structural defect into approximation, whereafter use of the thermoplastic polymer for molecular scale healing allowed for movement of the thermoplastic polymer into the defect and thus obtain molecular scale healing. The thermoplastic can be fibers, particles or spheres which are used by heating to a level at or above the thermoplastic's melting point, then cooling of the composition below the melting temperature of the thermoplastic. Compositions of the invention have the ability to not only close macroscopic defects, but also to do so repeatedly even if another wound/damage occurs in a previously healed/repaired area.

PEO + PVP blended polymer composite

Indian Academy of Sciences (India)

Blended polymer films of polyethylene oxide + polyvinyl pyrrolidone (PEO + PVP) containing transition metal (TM) ions like Fe3+, Co2+ and Ni2+ have been synthesized by a solution casting method. For these films, structural, thermal, magnetic and optical properties have been studied. X-ray diffraction results reveal the ...

Improvement of Scratch and Wear Resistance of Polymers by Fillers Including Nanofillers

Directory of Open Access Journals (Sweden)

Witold Brostow

2017-03-01

Full Text Available Polymers have lower resistance to scratching and wear than metals. Liquid lubricants work well for metals but not for polymers nor for polymer-based composites (PBCs. We review approaches for improvement of tribological properties of polymers based on inclusion of fillers. The fillers can be metallic or ceramic—with obvious consequences for electrical resistivity of the composites. Distinctions between effectiveness of micro- versus nano-particles are analyzed. For example, aluminum nanoparticles as filler are more effective for property improvement than microparticles at the same overall volumetric concentration. Prevention of local agglomeration of filler particles is discussed along with a technique to verify the prevention.

Layered plasma polymer composite membranes

Science.gov (United States)

Babcock, Walter C.

1994-01-01

Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is .gtoreq.2 and is the number of selective layers.

Joining of polymer-metal lightweight structures using self-piercing riveting (SPR) technique: Numerical approach and simulation results

Science.gov (United States)

Amro, Elias; Kouadri-Henni, Afia

2018-05-01

Restrictions in pollutant emissions dictated at the European Commission level in the past few years have urged mass production car manufacturers to engage rapidly several strategies in order to reduce significantly the energy consumption of their vehicles. One of the most relevant taken action is light-weighting of body in white (BIW) structures, concretely visible with the increased introduction of polymer-based composite materials reinforced by carbon/glass fibers. However, the design and manufacturing of such "hybrid" structures is limiting the use of conventional assembly techniques like resistance spot welding (RSW) which are not transferable as they are for polymer-metal joining. This research aims at developing a joining technique that would eventually enable the assembly of a sheet molding compound (SMC) polyester thermoset-made component on a structure composed of several high strength steel grades. The state of the art of polymer-metal joining techniques highlighted the few ones potentially able to respond to the industrial challenge, which are: structural bonding, self-piercing riveting (SPR), direct laser joining and friction spot welding (FSpW). In this study, the promising SPR technique is investigated. Modelling of SPR process in the case of polymer-metal joining was performed through the building of a 2D axisymmetric FE model using the commercial code Abaqus CAE 6.10-1. Details of the numerical approach are presented with a particular attention to the composite sheet for which Mori-Tanaka's homogenization method is used in order to estimate overall mechanical properties. Large deformations induced by the riveting process are enabled with the use of a mixed finite element formulation ALE (arbitrary Lagrangian-Eulerian). FE model predictions are compared with experimental data followed by a discussion.

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj; Khan, Yasser; Cha, Dong Kyu; Almadhoun, Mahmoud N.; Li, Ruipeng; Chen, Long; Amassian, Aram; Odeh, Ihab N.; Alshareef, Husam N.

2013-01-01

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj

2013-12-23

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

Process engineering and economic evaluations of diaphragm and membrane chlorine cell technologies. Final report

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

The chlor-alkali manufacturing technologies of (1), diaphragm cells (2), current technology membrane cells (3), catalytic cathode membrane cells (4), oxygen-cathode membrane cells and to a lesser extent several other related emerging processes are studied. Comparisons have been made on the two bases of (1) conventional industrial economics, and (2) energy consumption. The current diaphragm cell may have a small economic advantage over the other technologies at the plant size of 544 metric T/D (600 T/D). The three membrane cells all consume less energy, with the oxygen-cathode cell being the lowest. The oxygen-cathode cell appears promising as a low energy chlor-alkali cell where there is no chemical market for hydrogen. Federal funding of the oxygen-cathode cell has been beneficial to the development of the technology, to electrochemical cell research, and may help maintain the US's position in the international chlor-alkali technology marketplace. Tax law changes inducing the installation of additional cells in existing plants would produce the quickest reduction in power consumption by the chlor-alkali industry. Alternative technologies such as the solid polymer electrolyte cell, the coupling of diaphragm cells with fuel cells and the dynamic gel diaphragm have a strong potential for reducing chloralkali industry power consumption. Adding up all the recent and expected improvements that have become cost-effective, the electrical energy required to produce a unit of chlorine by 1990 should be only 50% to 60% of that used in 1970. In the United States the majority of the market does not demand salt-free caustic. About 75% of the electrolytic caustic is produced in diaphragm cells and only a small part of that is purified. This study indicates that unless membrane cell costs are greatly reduced or a stronger demand develops for salt-free caustic, the diaphragm cells will remain competitive. (WHK)

Self healing in polymers and polymer composites. Concepts, realization and outlook: A review

Directory of Open Access Journals (Sweden)

2008-04-01

Full Text Available Formation of microcracks is a critical problem in polymers and polymer composites during their service in structural applications. Development and coalescence of microcracks would bring about catastrophic failure of the materials and then reduce their lifetimes. Therefore, early sensing, diagnosis and repair of microcracks become necessary for removing the latent perils. In this context, the materials possessing self-healing function are ideal for long-term operation. Self-repairing polymers and polymer composites have attracted increasing research interests. Attempts have been made to develop solutions in this field. The present article reviews state-of-art of the achievements on the topic. According to the ways of healing, the smart materials are classified into two categories: (i intrinsic self-healing ones that are able to heal cracks by the polymers themselves, and (ii extrinsic in which healing agent has to be pre-embedded. The advances in this field show that selection and optimization of proper repair mechanisms are prerequisites for high healing efficiency. It is a challenging job to either invent new polymers with inherent crack repair capability or integrate existing materials with novel healing system.

Chemical microsensors based on polymer fiber composites

Science.gov (United States)

Kessick, Royal F.; Levit, Natalia; Tepper, Gary C.

2005-05-01

There is an urgent need for new chemical sensors for defense and security applications. In particular, sensors are required that can provide higher sensitivity and faster response in the field than existing baseline technologies. We have been developing a new solid-state chemical sensor technology based on microscale polymer composite fiber arrays. The fibers consist of an insulating polymer doped with conducting particles and are electrospun directly onto the surface of an interdigitated microelectrode. The concentration of the conducting particles within the fiber is controlled and is near the percolation threshold. Thus, the electrical resistance of the polymer fiber composite is very sensitive to volumetric changes produced in the polymer by vapor absorption. Preliminary results are presented on the fabrication and testing of the new microsensor. The objective is to take advantage of the very high surface to volume ratio, low thermal mass and linear geometry of the composite fibers to produce sensors exhibiting an extremely high vapor sensitivity and rapid response. The simplicity and low cost of a resistance-based chemical microsensor makes this sensing approach an attractive alternative to devices requiring RF electronics or time-of-flight analysis. Potential applications of this technology include battlespace awareness, homeland security, environmental surveillance, medical diagnostics and food process monitoring.

Thermoresistive mechanisms of carbon nanotube/polymer composites

Science.gov (United States)

Cen-Puc, M.; Oliva-Avilés, A. I.; Avilés, F.

2018-01-01

The mechanisms governing thermoresistivity of carbon nanotube (CNT)/polymer composites are theoretically and experimentally investigated. Two modeling approaches are proposed to this aim considering a broad range of CNT concentrations (0.5-50 wt%). In the first model, thermal expansion of the polymer composite is predicted using a finite element model; the resulting CNT-to-CNT separation distance feeds a classical tunneling model to predict the dependence of the electrical resistance with temperature. The second approach uses the general effective medium considering the dilution of the CNT volume fraction due to the thermal expansion of the polymer. Both models predict that the electrical resistance increases with increased temperature (i.e. a positive temperature coefficient of resistance, TCR) for all investigated CNT concentrations, with higher TCRs for lower CNT concentrations. Comparison between modeling outcomes and experimental data suggests that polymer thermal expansion (and tunneling) play a dominant role for low CNT concentrations (≤ 10 wt%) heated above room temperature. On the other hand, for composites at high CNT concentrations (50 wt%) or for freezing temperatures (-110 °C), a negative TCR was experimentally obtained, suggesting that for those conditions the CNT intrinsic thermoresistivity and the electronic conduction between CNTs by thermal activation may play a paramount role.

New Stethoscope With Extensible Diaphragm.

Science.gov (United States)

Takashina, Tsunekazu; Shimizu, Masashi; Muratake, Torakazu; Mayuzumi, Syuichi

2016-08-25

This study compared the diagnostic efficacy of the common suspended diaphragm stethoscope (SDS) with a new extensible diaphragm stethoscope (EDS) for low-frequency heart sounds. The EDS was developed by using an ethylene propylene diene monomer diaphragm. The results showed that the EDS enhanced both the volume and quality of low-frequency heart sounds, and improved the ability of examiners to auscultate such heart sounds. Based on the results of the sound analysis, the EDS is more efficient than the SDS. (Circ J 2016; 80: 2047-2049).

Irradiatable polymer composition with improved oxidation resistance

International Nuclear Information System (INIS)

Lyons, B.J.

1977-01-01

A method is described for the incorporation of a substantially insoluble organic phosphite into a polymer composition such as polyolefin polymers or ethylene copolymers to prevent oxidation of the polymer at elevated temperatures after radiation-induced crosslinking. The crosslinking is readily achieved without affecting the antioxidant properties of the organic phosphite. Particularly suitable organic compounds are derivatives of pentaerythritol, dipentaerythritol, and tripentaerythritol in cooncentrations of 1 to 3% of the mixture to be irradiated

Thin and Flexible Fe-Si-B/Ni-Cu-P Metallic Glass Multilayer Composites for Efficient Electromagnetic Interference Shielding.

Science.gov (United States)

Zhang, Jijun; Li, Jiawei; Tan, Guoguo; Hu, Renchao; Wang, Junqiang; Chang, Chuntao; Wang, Xinmin

2017-12-06

Thin and flexible materials that can provide efficient electromagnetic interference (EMI) shielding are urgently needed, especially if they can be easily processed and withstand harsh environments. Herein, layer-structured Fe-Si-B/Ni-Cu-P metallic glass composites have been developed by simple electroless plating Ni-Cu-P coating on commercial Fe-Si-B metallic glasses. The 0.1 mm-thick composite shows EMI shielding effectiveness of 40 dB over the X-band frequency range, which is higher than those of traditional metals, metal oxides, and their polymer composites of larger thickness. Most of the applied electromagnetic waves are proved to be absorbed rather than bounced back. This performance originates from the combination of a superior soft magnetic property, excellent electrical conductivity, and multiple internal reflections from multilayer composites. In addition, the flexible composites also exhibit good corrosion resistance, high thermal stability, and excellent tensile strength, making them suitable for EMI shielding in harsh chemical or thermal environments.

Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

KAUST Repository

Srivastava, Samanvaya; Agarwal, Praveen; Archer, Lynden A.

2012-01-01

different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer

Use of Hydrophilic Insoluble Polymers in the Restoration of Metal-Contaminated Soils

Directory of Open Access Journals (Sweden)

Guiwei Qu

2009-01-01

Full Text Available To develop cost-effective techniques that contribute to phytostabilization of severely metal-contaminated soils is a necessary task in environmental research. Hydrophilic insoluble polymers have been used for some time in diapers and other hygienic products and to increase the water-holding capacity of coarse-textured soils. These polymers contain groups, such as carboxyl groups, that are capable of forming bonds with metallic cations, thereby decreasing their bioavailability in soils. The use of polyacrylate polymers as soil amendments to restore metal-contaminated soils has been investigated in the Technical University of Lisbon since the late nineties. Plant growth and plant nutrients concentrations, extractable levels of metals in soil, and soil enzyme activities were used to monitor the improvement in soil quality following the application of these polymers. In contaminated soils, hydrophilic insoluble polymers can create microcosms that are rich in water and nutrients (counterions but only contain small concentrations of toxic elements; the conditions of these microenvironments are favorable to roots and microorganisms. In this paper we described the most relevant information available about this topic.

Use of Hydrophilic Insoluble Polymers in the Restoration of Metal-Contaminated Soils

International Nuclear Information System (INIS)

Qu, G.; De Varennes, A.; Qu, G.

2010-01-01

To develop cost-effective techniques that contribute to phyto stabilization of severely metal-contaminated soils is a necessary task in environmental research. Hydrophilic insoluble polymers have been used for some time in diapers and other hygienic products and to increase the water-holding capacity of coarse-textured soils. These polymers contain groups, such as carboxyl groups, that are capable of forming bonds with metallic cations, thereby decreasing their bioavailability in soils. The use of polyacrylate polymers as soil amendments to restore metal-contaminated soils has been investigated in the Technical University of Lisbon since the late nineties. Plant growth and plant nutrients concentrations, extractable levels of metals in soil, and soil enzyme activities were used to monitor the improvement in soil quality following the application of these polymers. In contaminated soils, hydrophilic insoluble polymers can create microcosms that are rich in water and nutrients (counterions) but only contain small concentrations of toxic elements; the conditions of these micro environments are favorable to roots and microorganisms. In this paper we described the most relevant information available about this topic.

Removal and recovery of metal ions from process and waste streams using polymer filtration

International Nuclear Information System (INIS)

Jarvinen, G.D.; Smith, B.F.; Robison, T.W.; Kraus, K.M.; Thompson, J.A.

1999-01-01

Polymer Filtration (PF) is an innovative, selective metal removal technology. Chelating, water-soluble polymers are used to selectively bind the desired metal ions and ultrafiltration is used to concentrate the polymer-metal complex producing a permeate with low levels of the targeted metal ion. When applied to the treatment of industrial metal-bearing aqueous process streams, the permeate water can often be reused within the process and the metal ions reclaimed. This technology is applicable to many types of industrial aqueous streams with widely varying chemistries. Application of PF to aqueous streams from nuclear materials processing and electroplating operations will be described

Synthesis of new water-soluble metal-binding polymers: Combinatorial chemistry approach. 1997 mid-year progress report

International Nuclear Information System (INIS)

Smith, B.F.

1997-01-01

'The first objective of this research is to develop rapid discovery and optimization approaches to new water-soluble chelating polymers. A byproduct of the development approach will be the new, selective, and efficient metal-binding agents. The second objective is to evaluate the concept of using water and organic soluble polymers as new solid supports for combinatorial synthesis. The technology under development, Polymer Filtration (PF), is a technique to selectively remove or recover hazardous and valuable metal ions and radionuclides from various dilute aqueous streams. Not only can this technology be used to remediate contaminated soils and solid surfaces and treat aqueous wastes, it can also be incorporated into facilities as a pollution prevention and waste minimization technology. Polymer Filtration uses water-soluble metal-binding polymers to sequester metal ions in dilute solution. The water-soluble polymers have a sufficiently large molecular size that they can be separated and concentrated using commercial ultrafiltration technology. Water, small organic molecules, and unbound metals pass freely through the ultrafiltration membrane while concentrating the metal-binding polymer. The polymers can then be reused by changing the solution conditions to release the metal ions. The metal-ions are recovered in concentrated form for recycle or disposal using a diafiltration process. The water-soluble polymer can be recycled for further aqueous-stream processing. To advance Polymer Filtration technology to the selectivity levels required for DOE needs. fixture directions in Polymer Filtration must include rapid development, testing, and characterization of new metal-binding polymers. The development of new chelating molecules can be equated to the process of new drugs or new materials discovery. Thus, the authors want to build upon and adapt the combinatorial chemistry approaches developed for rapid molecule generation for the drug industry to the rapid

Synthesis of new water-soluble metal-binding polymers: Combinatorial chemistry approach. 1998 annual progress report

International Nuclear Information System (INIS)

Kurth, M.J.; Miller, R.B.; Sawan, S.; Smith, B.F.

1998-01-01

'(1) Develop rapid discovery and optimization approaches to new water-soluble chelating polymers for use in Polymer Filtration (PF) systems, and (2) evaluate the concept of using water and organic soluble polymers as new solid supports for combinatorial synthesis. Polymer Filtration (PF), which uses water-soluble metal-binding polymers to sequester metal ions in dilute solution with ultrafiltration (UF) to separate the polymers, is a new technology to selectively remove or recover hazardous and valuable metal ions. Future directions in PF must include rapid development, testing, and characterization of new metal-binding polymers. Thus, the authors are building upon and adapting the combinatorial chemistry approach developed for rapid molecule generation for the drug industry to the rapid development of new chelating polymers. The authors have focused on four areas including the development of: (1) synthetic procedures, (2) small ultrafiltration equipment compatible with organic- and aqueous-based combinatorial synthesis, (3) rapid assay techniques, and (4) polymer characterization techniques.'

New trends in the optical and electronic applications of polymers containing transition-metal complexes.

Science.gov (United States)

Liu, Shu-Juan; Chen, Yang; Xu, Wen-Juan; Zhao, Qiang; Huang, Wei

2012-04-13

Polymers containing transition-metal complexes exhibit excellent optical and electronic properties, which are different from those of polymers with a pure organic skeleton and combine the advantages of both polymers and metal complexes. Hence, research about this class of polymers has attracted more and more interest in recent years. Up to now, a number of novel polymers containing transition-metal complexes have been exploited, and significant advances in their optical and electronic applications have been achieved. In this article, we summarize some new research trends in the applications of this important class of optoelectronic polymers, such as chemo/biosensors, electronic memory devices and photovoltaic devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymer composites with carbon nanotube for application of radiation attenuator in medical procedures

Energy Technology Data Exchange (ETDEWEB)

Fontainha, C.C.P.; Nunes, M.; Rosas, V.A., E-mail: crissia@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem; Furtado, C.A.; Faria, L.O. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Medical radiology offers great benefit to patients, however, the radiation contributes for the workers and individuals exposure, significantly increasing dose to population. New attenuators materials have been widely investigated for radiation shielding to apply in medical procedures. Polymeric composites filled with attenuating metals and functionalized with carbon nanotubes (NTC) are being largely developed. In this work, composites were produced for radiation attenuation in radiodiagnostic imaging procedures. Two types of polymer matrices, polyvinylidene fluoride, PVDF, and its copolymer, poly(vinylidene-trifluorylene fluoride), P(VDF-TrFE), were filled bismuth oxide nanoparticles. Carbon nanotubes were added with different concentrations at the solution of attenuator metal under controlled magnetic stirring. The composites were characterized by differential heat flow scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and dispersive energy X-ray spectrometry (EDS) for thermal analysis. In this setup, one reference measure is directly exposed to the x-rays being diffracted by single crystal of Si (111). Another measure the attenuated beam is performed with the composite sample under detector. The samples present a good dispersion of the attenuator metal and the nanotube carbon. On the other hand, composites with PVDF matrix lost their plasticity, stiffening their structure, becoming brittle, even using the same methodology of synthesis. The P(VDF-Trfe) matrix showed better maleability than PVDF matrix. The cheaptube dispersion in the P(VDF-Trfe) matrix presented better than the 3100 carbon nanotubes. The attenuation for 8.047 keV monoenergetic photons was about 90% to 100 μm thickness for all composites. (author)

Polymer composites with carbon nanotube for application of radiation attenuator in medical procedures

International Nuclear Information System (INIS)

Fontainha, C.C.P.; Nunes, M.; Rosas, V.A.

2017-01-01

Medical radiology offers great benefit to patients, however, the radiation contributes for the workers and individuals exposure, significantly increasing dose to population. New attenuators materials have been widely investigated for radiation shielding to apply in medical procedures. Polymeric composites filled with attenuating metals and functionalized with carbon nanotubes (NTC) are being largely developed. In this work, composites were produced for radiation attenuation in radiodiagnostic imaging procedures. Two types of polymer matrices, polyvinylidene fluoride, PVDF, and its copolymer, poly(vinylidene-trifluorylene fluoride), P(VDF-TrFE), were filled bismuth oxide nanoparticles. Carbon nanotubes were added with different concentrations at the solution of attenuator metal under controlled magnetic stirring. The composites were characterized by differential heat flow scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and dispersive energy X-ray spectrometry (EDS) for thermal analysis. In this setup, one reference measure is directly exposed to the x-rays being diffracted by single crystal of Si (111). Another measure the attenuated beam is performed with the composite sample under detector. The samples present a good dispersion of the attenuator metal and the nanotube carbon. On the other hand, composites with PVDF matrix lost their plasticity, stiffening their structure, becoming brittle, even using the same methodology of synthesis. The P(VDF-Trfe) matrix showed better maleability than PVDF matrix. The cheaptube dispersion in the P(VDF-Trfe) matrix presented better than the 3100 carbon nanotubes. The attenuation for 8.047 keV monoenergetic photons was about 90% to 100 μm thickness for all composites. (author)

Bulk metallic glass matrix composites

International Nuclear Information System (INIS)

Choi-Yim, H.; Johnson, W.L.

1997-01-01

Composites with a bulk metallic glass matrix were synthesized and characterized. This was made possible by the recent development of bulk metallic glasses that exhibit high resistance to crystallization in the undercooled liquid state. In this letter, experimental methods for processing metallic glass composites are introduced. Three different bulk metallic glass forming alloys were used as the matrix materials. Both ceramics and metals were introduced as reinforcement into the metallic glass. The metallic glass matrix remained amorphous after adding up to a 30 vol% fraction of particles or short wires. X-ray diffraction patterns of the composites show only peaks from the second phase particles superimposed on the broad diffuse maxima from the amorphous phase. Optical micrographs reveal uniformly distributed particles in the matrix. The glass transition of the amorphous matrix and the crystallization behavior of the composites were studied by calorimetric methods. copyright 1997 American Institute of Physics

Polymer-supported reagents with enhanced metal ion recognition: Application to separations science

International Nuclear Information System (INIS)

Alexandratos, S.D.

1993-01-01

The design and development of polymer-supported reagents with ever-increasing specificities for targeted metal ions remains an important areas of research. The need for efficient separation schemes for both ions and molecules has been outlined in a report by the National Research Council (King) and will gain increased emphasis as environmental restoration is pursued. Polymer-supported reagents are unique in their ability to be applied in an environmentally benign manner to a host of challenges. Such reagents, in the form of beads, can be applied to continuous separation processes ranging from the removal of metal ions in water to the recovery of medicinal drugs produced through biotechnological means. The application of polymer-supported reagents to metal ion separations still requires developing a fundamental understanding of ligand-metal interactions, the role of the polymer in those interactions, and the methods of synthesizing such polymeric reagents in a readily applicable form. Ion exchange resins with sulfonic acid ligands are the prototypical polymer-supported reagents, and their properties have been exhaustively studied (Helfferich). The high acidity of the sulfonic acid group, however, precludes much selectivity, and it displays a very limited range of reaction free energy values with different metal ions (Boyd et al.). The carboxylic acid ligand, present in the acrylate resins, is more selective, though its weak acidity requires relatively high pH solutions for it to be effective. Research has thus been focused on the preparation of polymer-supported reagents with high levels of specificity for targeted metal ions

The application of radiothermoluminescence method to the analysis of polymers and polymer composites

International Nuclear Information System (INIS)

Nikol'skii, V.G.

1982-01-01

The basic results concerning the examination of copolymers, cross-linked polymers and polyblends structure, obtained by means of radiothermoluminescence method, are reviewed. The main emphasis is on the glow curve shape analysis that allows: a) to determine quantitatively the random copolymer composition; b) to reveal the existence of blocks in macromolecules; c) to examine the grafted copolymer distribution in polymer matrix; d) to estimate the degree of cross-linking both for individual polymers and heterogeneous polyblends; e) to study the mutual solubility of polymers. (author)

Positron beam analysis of polymer/metal interfaces under stress

NARCIS (Netherlands)

Escobar Galindo, R.; van Veen, A.; Garcia, A.A.; Schut, H.; de Hosson, J.T.M.; Triftshauser, W; Kogel, G; Sperr, P

2001-01-01

The polymers Epoxy and Poly(Methyl MethAcrylate) spin coated on Interstitial Free (IF) steel were subjected to external stresses and studied using the Delft Variable Energy Positron (VEP) beam facility. The polymer/metal interface was identified using an S-W map. After tensile experiments vacancy

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metal/polymer... § 888.3390 Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis is a two-part...

Chemical metallization of KMPR photoresist polymer in aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Zeb, Gul [MiQro Innovation Collaborative Centre (C2MI), 45, boul. de l' Aéroport, Bromont, QC, J2L 1S8 (Canada); Mining & Materials Engineering, McGill University, 3610,University Street, Montreal, QC, H3A 0C5 (Canada); Duong, Xuan Truong [Department of Mechanical Engineering, Ecole polytechnique de Montréal, Montréal, QC, H3C 3T5 (Canada); Thai Nguyen University of Technology, 3-2 Street, Thai Nguyen City (Viet Nam); Vu, Ngoc Pi; Phan, Quang The; Nguyen, Duc Tuong; Ly, Viet Anh [Thai Nguyen University of Technology, 3-2 Street, Thai Nguyen City (Viet Nam); Salimy, Siamak [ePeer Review LLC, 145 Pine Haven Shores Rd, Suite 1000-X, Shelburne, VT 05482 (United States); Le, Xuan Tuan, E-mail: xuantuan.le@teledyne.com [MiQro Innovation Collaborative Centre (C2MI), 45, boul. de l' Aéroport, Bromont, QC, J2L 1S8 (Canada); Thai Nguyen University of Technology, 3-2 Street, Thai Nguyen City (Viet Nam)

2017-06-15

Highlights: • Electroless deposition of Ni-B film on KMPR photoresist polymer insulator with excellent adhesion has been achieved. • This metallization has been carried out in aqueous solutions at low temperature. • Polyamine palladium complexes grafts serve as seeds for the electroless plating on KMPR. • This electroless metallization process is simple, industrially feasible, chromium-free and environment-friendly. - Abstract: While conventional methods for preparing thin films of metals and metallic alloys on insulating substrates in the field of microelectromechanical systems (MEMS) include vapor deposition techniques, we demonstrate here that electroless deposition can be considered as an alternate efficient approach to metallize the surface of insulating substrates, such as KMPR epoxy photoresist polymer. In comparison with the physical and chemical vapor deposition methods, which are well-established for metallization of photoresist polymers, our electroless nickel plating requires only immersing the substrates into aqueous solutions in open air at low temperatures. Thin films of nickel alloy have been deposited electrolessly on KMPR surface, through a cost-effective and environmental chromium-free process, mediated through direct grafting of amine palladium complexes in aqueous medium. This covalent organic coating provides excellent adhesion between KMPR and the nickel film and allows better control of the palladium catalyst content. Covalent grafting and characterization of the deposited nickel film have been carried out by means of Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy techniques.

Gas phase sensing of alcohols by Metal Organic Framework – polymer composite materials

NARCIS (Netherlands)

Sachdeva, S.; Koper, Sander J.H.; Sabetghadam, Anahid; Soccol, D.; Gravesteijn, Dirk J; Kapteijn, Freek; Sudholter, Ernst J.R.; Gascon, Jorge; de Smet, Louis C.P.M.

2017-01-01

Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH2-MIL-53(Al) were dispersed in

Charge Injection and Transport in Metal/Polymer Chains/Metal Sandwich Structure

International Nuclear Information System (INIS)

Hai-Hong, Li; Dong-Mei, Li; Yuan, Li; Kun, Gao; De-Sheng, Liu; Shi-Jie, Xie

2008-01-01

Using the tight-binding Su–Schrieffer–Heeger model and a nonadiabatic dynamic evolution method, we study the dynamic processes of the charge injection and transport in a metal/two coupled conjugated polymer chains/metal structure. It is found that the charge interchain transport is determined by the strength of the electric field and the magnitude of the voltage bias applied on the metal electrode. The stronger electric field and the larger voltage bias are both in favour of the charge interchain transport. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Preparation of pinewood/polymer/composites using gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Ajji, Zaki [Polymer Technology Division, Department of Radiation Technology, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)]. E-mail: atomic@aec.org.sy

2006-09-15

Wood/polymer composites (WPC) have been prepared from pinewood with different compounds using gamma irradiation: butyl acrylate, butyl methacrylate, styrene, acrylamide, acrylonitrile, and unsaturated polyester styrene resin. The polymer loading was determined with respect to the compound concentration and the irradiation dose. The polymer loading increases generally with increase in the monomer or polymer concentration. Tensile and compression strength have been improved in the four cases, but no improvement was observed using unsaturated polyester styrene resin or acrylamide.

Evaluation of Effective Diaphragm Area for Pneumatic Actuator

International Nuclear Information System (INIS)

Ryu, Hogeun; Han, Bongsub; Seon, Juhyoung

2016-01-01

The purpose of this study is to develop a methodology to calculate the exact effective diaphragm area using the results of diagnostic test to be performed in the evaluation of air operated valve performance. By using this developed methodology in pneumatic actuator performance evaluation, it can be reduce the possible errors arising from effective diaphragm area in the evaluation of performance of air operated valves. The performance assessment for the operability and structural integrity of air operated valves for the domestic nuclear power plant is in progress. One of the important parameters that determine the performance of the air operated valves is the effective diaphragm area of diaphragm type actuator. The effective diaphragm area is the actual area which the air pressure acting on the diaphragm. In general, the effective diaphragm area used for the performance evaluation of pneumatic actuator is provided by the manufacture or the actuator drawing. Flat type diaphragm was showed the difference between the measured value of EDA and the manufacture’s value, in the case of convoluted type diaphragm has showed that the measured value of EDA and manufacture’s value is almost the same. When evaluate a performance of a diaphragm actuator, accurate EDA is to be used because it is an important variable affecting the actuator performance. Particularly in the case of flat type diaphragm which EDA is changed in accordance with the stroke position, by using the EDA evaluation methodology developed in this study to minimize a possible error due to EDA when evaluating the performance of the air actuator

Evaluation of Effective Diaphragm Area for Pneumatic Actuator

Energy Technology Data Exchange (ETDEWEB)

Ryu, Hogeun; Han, Bongsub; Seon, Juhyoung [SOOSAN INDUSTRIES, Seoul (Korea, Republic of)

2016-10-15

The purpose of this study is to develop a methodology to calculate the exact effective diaphragm area using the results of diagnostic test to be performed in the evaluation of air operated valve performance. By using this developed methodology in pneumatic actuator performance evaluation, it can be reduce the possible errors arising from effective diaphragm area in the evaluation of performance of air operated valves. The performance assessment for the operability and structural integrity of air operated valves for the domestic nuclear power plant is in progress. One of the important parameters that determine the performance of the air operated valves is the effective diaphragm area of diaphragm type actuator. The effective diaphragm area is the actual area which the air pressure acting on the diaphragm. In general, the effective diaphragm area used for the performance evaluation of pneumatic actuator is provided by the manufacture or the actuator drawing. Flat type diaphragm was showed the difference between the measured value of EDA and the manufacture’s value, in the case of convoluted type diaphragm has showed that the measured value of EDA and manufacture’s value is almost the same. When evaluate a performance of a diaphragm actuator, accurate EDA is to be used because it is an important variable affecting the actuator performance. Particularly in the case of flat type diaphragm which EDA is changed in accordance with the stroke position, by using the EDA evaluation methodology developed in this study to minimize a possible error due to EDA when evaluating the performance of the air actuator.

Application of β-cyclodextrin polymers in separation of metal ions

International Nuclear Information System (INIS)

Kozlowski, C.A.; Kozlowska, J.

2006-01-01

In the present work the competitive transport of Cu(II), Co(II), Ni(II) and Zn(II) ions through the plasticized immobilized membranes was studied. β-cyclodextrin (β-CD) polymers have been used as macrocyclic ligands for separation of metal ions from dilute aqueous solutions by ion exchange methods, i.e. transport across polymer inclusion membranes and ion flotation process. β-CD polymers were prepared by cross-linking β-CD with alkenyl (nonenyl) succinic anhydride derivatives, phtalic and 3-nitrophtalic anhydride in anhydrous N,N-dimethylformamide (DMF) resulting in formation of Polymer A, B or C, respectively. In he case of cooper(II) flotation results obtained with the use of nonylphenol polyoxyethyl glycol ether as an non-anionic surfactant and β-CD polymers as complexation agent, show that the removal of metal decreases with higher molecular mass of β-CD polymers linked by phtalic or 3-nitrophtalic anhydrides. For both derivatives with pH increase the copper(II) removed increase. The highest flotation removal, i.e. 93% is observed for β-CD polymers synthesized at 100 o C with molar ratio CD : NaH : 3-nitrophtalic anhydride equal to 1 : 7 : 7

Semi-metallic, strong conductive polymer microfiber, method and fast response rate actuators and heating textiles

KAUST Repository

Zhou, Jian; Li, Er Qiang; Lubineau, Gilles; Thoroddsen, Sigurdur T; Mulle, Matthieu

2016-01-01

A method comprising: providing at least one first composition comprising at least one conjugated polymer and at least one solvent, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one fiber to form at least one second fiber material. In lead embodiments, high-performance poly(3,4-ethylenedioxy- thiophene)/poly(styrenesulfonate) (PEDOT/PSS) conjugated polymer microfibers were fabricated via wet- spinning followed by hot-drawing. In these lead embodiments, due to the combined effects of the vertical hot-drawing process and doping/de-doping the microfibers with ethylene glycol (EG), a record electrical conductivity of 2804 S · cm-1 was achieved. This is believed to be a six-fold improvement over the best previously reported value for PEDOT/PSS fibers (467 S · cm-1) and a twofold improvement over the best values for conductive polymer films treated by EG de-doping (1418 S · cm-1). Moreover, these lead, highly conductive fibers experience a semiconductor-metal transition at 313 K. They also have superior mechanical properties with a Young's modulus up to 8.3 GPa, a tensile strength reaching 409.8 MPa and a large elongation before failure (21%). The most conductive fiber also demonstrates an extraordinary electrical performance during stretching/unstretching: the conductivity increased by 25% before the fiber rupture point with a maximum strain up to 21%. Simple fabrication of the semi-metallic, strong and stretchable wet-spun PEDOT/PSS microfibers can make them available for conductive smart electronics. A dramatic improvement in electrical conductivity is needed to make conductive polymer fibers viable candidates in applications such as flexible electrodes, conductive textiles, and fast-response sensors and actuators.

Semi-metallic, strong conductive polymer microfiber, method and fast response rate actuators and heating textiles

KAUST Repository

Zhou, Jian

2016-06-09

A method comprising: providing at least one first composition comprising at least one conjugated polymer and at least one solvent, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one fiber to form at least one second fiber material. In lead embodiments, high-performance poly(3,4-ethylenedioxy- thiophene)/poly(styrenesulfonate) (PEDOT/PSS) conjugated polymer microfibers were fabricated via wet- spinning followed by hot-drawing. In these lead embodiments, due to the combined effects of the vertical hot-drawing process and doping/de-doping the microfibers with ethylene glycol (EG), a record electrical conductivity of 2804 S · cm-1 was achieved. This is believed to be a six-fold improvement over the best previously reported value for PEDOT/PSS fibers (467 S · cm-1) and a twofold improvement over the best values for conductive polymer films treated by EG de-doping (1418 S · cm-1). Moreover, these lead, highly conductive fibers experience a semiconductor-metal transition at 313 K. They also have superior mechanical properties with a Young\\'s modulus up to 8.3 GPa, a tensile strength reaching 409.8 MPa and a large elongation before failure (21%). The most conductive fiber also demonstrates an extraordinary electrical performance during stretching/unstretching: the conductivity increased by 25% before the fiber rupture point with a maximum strain up to 21%. Simple fabrication of the semi-metallic, strong and stretchable wet-spun PEDOT/PSS microfibers can make them available for conductive smart electronics. A dramatic improvement in electrical conductivity is needed to make conductive polymer fibers viable candidates in applications such as flexible electrodes, conductive textiles, and fast-response sensors and actuators.

Molecular modeling of polymer composite-analyte interactions in electronic nose sensors

Science.gov (United States)

Shevade, A. V.; Ryan, M. A.; Homer, M. L.; Manfreda, A. M.; Zhou, H.; Manatt, K. S.

2003-01-01

We report a molecular modeling study to investigate the polymer-carbon black (CB) composite-analyte interactions in resistive sensors. These sensors comprise the JPL electronic nose (ENose) sensing array developed for monitoring breathing air in human habitats. The polymer in the composite is modeled based on its stereoisomerism and sequence isomerism, while the CB is modeled as uncharged naphthalene rings with no hydrogens. The Dreiding 2.21 force field is used for the polymer, solvent molecules and graphite parameters are assigned to the carbon black atoms. A combination of molecular mechanics (MM) and molecular dynamics (NPT-MD and NVT-MD) techniques are used to obtain the equilibrium composite structure by inserting naphthalene rings in the polymer matrix. Polymers considered for this work include poly(4-vinylphenol), polyethylene oxide, and ethyl cellulose. Analytes studied are representative of both inorganic and organic compounds. The results are analyzed for the composite microstructure by calculating the radial distribution profiles as well as for the sensor response by predicting the interaction energies of the analytes with the composites. c2003 Elsevier Science B.V. All rights reserved.

Method of Making an Electroactive Sensing/Actuating Material for Carbon Nanotube Polymer Composite

Science.gov (United States)

Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

2009-01-01

An electroactive sensing or actuating material comprises a composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation of the composite when such composite is affected by an external stimulus. In another embodiment, the composite comprises a, third component of micro -sized to nano-sized particles of an electroactive ceramic that is also incorporated in the polymer matrix. The method for making the three-phase composite comprises either incorporating the carbon nanotubes in the polymer matrix before incorporation of the particles of ceramic or mixing the carbon nanotubes and particles of ceramic together in a solution before incorporation in the polymer matrix.

Buckling behavior of fiber reinforced plastic–metal hybrid-composite beam

International Nuclear Information System (INIS)

Eksi, Secil; Kapti, Akin O.; Genel, Kenan

2013-01-01

Highlights: ► We developed a new plastic–metal hybrid-composite tubular beam structure. ► This structure offers innovative design solutions with weight reduction. ► It prevents premature buckling without adding significant weight to the structure. ► The composite interaction gives better mechanical properties to the products. ► Buckling and bending loads of the beam increased 3.2 and 7.6 times, respectively. - Abstract: It is known that the buckling is characterized by a sudden failure of a structural member subjected to high compressive load. In this study, the buckling behavior of the aluminum tubular beam (ATB) was analyzed using finite element (FE) method, and the reinforcing arrangements as well as its combinations were decided for the composite beams based on the FE results. Buckling and bending behaviors of thin-walled ATBs with internal cast polyamide (PA6) and external glass and carbon fiber reinforcement polymers (GFRPs and CFRPs) were investigated systematically. Experimental studies showed that the 219% increase in buckling load and 661% in bending load were obtained with reinforcements. The use of plastics and metal together as a reinforced structure yields better mechanical performance properties such as high resistance to buckling and bending loads, dimensional stability and high energy absorption capacity, including weight reduction. While the thin-walled metallic component provides required strength and stiffness, the plastic component provides the support necessary to prevent premature buckling without adding significant weight to the structure. It is thought that the combination of these materials will offer a promising new focus of attention for designers seeking more appropriate composite beams with high buckling loads beside light weight. The developed plastic–metal hybrid-composite structure is promising especially for critical parts serving as a support member of vehicles for which light weight is a critical design

Investigation of a nanoconfined, ceramic composite, solid polymer electrolyte

International Nuclear Information System (INIS)

Jayasekara, Indumini; Poyner, Mark; Teeters, Dale

2017-01-01

The challenges for further development of lithium rechargeable batteries are finding electrolyte materials that are safe, have mechanical and thermal stability and have sufficiently high ionic conduction. Polymer electrolytes have many of these advantages, but suffer with low ionic conduction. This study involves the use of anodic aluminum oxide (AAO) membranes having nanochannels filled with polymer electrolyte to make composite solid electrolytes having ionic conductivity several orders of magnitude higher (10 −4 Ω ‐1 cm −1 ) than non-confined polymer. SEM, ac impedance spectroscopy, temperature dependence studies, XRD, ATR- FTIR and DSC studies were done in order to characterize and understand the behavior of nanoconfined polymer electrolytes. The composite polymer electrolyte was found to be more amorphous with polymer chains aligned in the direction of the nanochannels, which is felt to promote ion conduction. The electrolyte systems, confined in nanoporous membranes, can be used as electrolytes for the fabrication of a room temperature all solid state battery.

21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femorotibial metal/polymer constrained... Knee joint femorotibial metal/polymer constrained cemented prosthesis. (a) Identification. A knee joint... of a knee joint. The device limits translation or rotation in one or more planes and has components...

Additive Manufacturing of Metallic and Ceramic Components by the Material Extrusion of Highly-Filled Polymers: A Review and Future Perspectives.

Science.gov (United States)

Gonzalez-Gutierrez, Joamin; Cano, Santiago; Schuschnigg, Stephan; Kukla, Christian; Sapkota, Janak; Holzer, Clemens

2018-05-18

Additive manufacturing (AM) is the fabrication of real three-dimensional objects from metals, ceramics, or plastics by adding material, usually as layers. There are several variants of AM; among them material extrusion (ME) is one of the most versatile and widely used. In MEAM, molten or viscous materials are pushed through an orifice and are selectively deposited as strands to form stacked layers and subsequently a three-dimensional object. The commonly used materials for MEAM are thermoplastic polymers and particulate composites; however, recently innovative formulations of highly-filled polymers (HP) with metals or ceramics have also been made available. MEAM with HP is an indirect process, which uses sacrificial polymeric binders to shape metallic and ceramic components. After removing the binder, the powder particles are fused together in a conventional sintering step. In this review the different types of MEAM techniques and relevant industrial approaches for the fabrication of metallic and ceramic components are described. The composition of certain HP binder systems and powders are presented; the methods of compounding and filament making HP are explained; the stages of shaping, debinding, and sintering are discussed; and finally a comparison of the parts produced via MEAM-HP with those produced via other manufacturing techniques is presented.

Additive Manufacturing of Metallic and Ceramic Components by the Material Extrusion of Highly-Filled Polymers: A Review and Future Perspectives

Science.gov (United States)

Cano, Santiago

2018-01-01

Additive manufacturing (AM) is the fabrication of real three-dimensional objects from metals, ceramics, or plastics by adding material, usually as layers. There are several variants of AM; among them material extrusion (ME) is one of the most versatile and widely used. In MEAM, molten or viscous materials are pushed through an orifice and are selectively deposited as strands to form stacked layers and subsequently a three-dimensional object. The commonly used materials for MEAM are thermoplastic polymers and particulate composites; however, recently innovative formulations of highly-filled polymers (HP) with metals or ceramics have also been made available. MEAM with HP is an indirect process, which uses sacrificial polymeric binders to shape metallic and ceramic components. After removing the binder, the powder particles are fused together in a conventional sintering step. In this review the different types of MEAM techniques and relevant industrial approaches for the fabrication of metallic and ceramic components are described. The composition of certain HP binder systems and powders are presented; the methods of compounding and filament making HP are explained; the stages of shaping, debinding, and sintering are discussed; and finally a comparison of the parts produced via MEAM-HP with those produced via other manufacturing techniques is presented. PMID:29783705

Welding of a metal-polymer laminate

NARCIS (Netherlands)

Gower, H.L.

2007-01-01

The purpose of this work is to investigate the weldability of a metal polymer sandwich structure. The welding of the sandwich material proceeds first by welding of the skin layer. The material selected for this research is Steelite, a sandwich structure developed by Corus, with 0.12 mm thick mild

Thermal Degradation of Lead Monoxide Filled Polymer Composite Radiation Shields

International Nuclear Information System (INIS)

Harish, V.; Nagaiah, N.

2011-01-01

Lead monoxide filled Isophthalate resin particulate polymer composites were prepared with different filler concentrations and investigated for physical, thermal, mechanical and gamma radiation shielding characteristics. This paper discusses about the thermo gravimetric analysis of the composites done to understand their thermal properties especially the effect of filler concentration on the thermal stability and degradation rate of composites. Pristine polymer exhibits single stage degradation whereas filled composites exhibit two stage degradation processes. Further, the IDT values as well as degradation rates decrease with the increased filler content in the composite.

Electrochemical properties of polypyrrole/polyfuran polymer composite electrode

International Nuclear Information System (INIS)

Cha, Seong Keuck

1998-01-01

Poly pyrrole polymer(ppy) has an excellent electrical conductivity and can be easily polymerized on anode to give various morphology according to doped anion on electroactive sites. To improve the properties of brittleness, ageing and hydrophobicity, poly furan polymer(pfu) having a high initiation potential was anodically implanted in this porous ppy film matrix to get the Pt/ppy/pfu(x)type of polymer campsite electrode. Cyclic voltammetry and electrochemical impedance methods were used to these electrode, where PF 6 - , BF 4 - , and ClO 4 - ions were employed as dopants. The composition of the pfu(x) at the electrode was changed from 0 to 1.10, but the range was useful only at 0.1 to 0.2 as the redox electrode. The polymer composite electrode doped with PF 6 - was better in charge transfer resistance by a factor of 40 times and in double layer capacitance by a factor of 20 times than others. The charge transfer in the polymer film of the electrode was influenced on frequency change and equivalent circuit of this electrode had Warburg impedance including mass transfer

Cement-Polymer Composite Containers for Radioactive Wastes Disposal

International Nuclear Information System (INIS)

Ghattas, N.K.; Eskander, S.B.; Bayoumi, T.A.; Saleh, H.M.

2009-01-01

Improving cement-composite containers using polymer as organic additives was studied extensively. Both unsaturated styrenated polyester (SPE) and polymethyl methacrylate (PMMA) were used to fill the pores in cement containers that used for disposal of radioactive wastes. Two different techniques were adopted for the addition of organic polymers based on their viscosity. The low density PMMA was added using impregnation technique. On the other hand high density SPE was mixed with cement paste as a premix process. Predetermined weight of dried borate radioactive powder waste simulate was introduced into the Cement-polymer composite (CPC) container and then closed before subjecting it to leaching characterization. The effect of the organic polymers on the hydration of cement matrix and on the properties of the obtained CPC container has been studied using X-ray diffraction, IR-analysis, thermal effects and weight loss. Porosity, pore parameters and rate of release were also determined. The results obtained showed that for the candidate CPC container positive effect of polymer dominates and an improvement in the retardation rate of PMMA release radionuclides was observed

Active Tube-Shaped Actuator with Embedded Square Rod-Shaped Ionic Polymer-Metal Composites for Robotic-Assisted Manipulation

Directory of Open Access Journals (Sweden)

Yanjie Wang

2018-01-01

Full Text Available This paper reports a new technique involving the design, fabrication, and characterization of an ionic polymer-metal composite- (IPMC- embedded active tube, which can achieve multidegree-of-freedom (MODF bending motions desirable in many applications, such as a manipulator and an active catheter. However, traditional strip-type IPMC actuators are limited in only being able to generate 1-dimensional bending motion. So, in this paper, we try to develop an approach which involves molding or integrating rod-shaped IPMC actuators into a soft silicone rubber structure to create an active tube. We modified the Nafion solution casting method and developed a complete sequence of a fabrication process for rod-shaped IPMCs with square cross sections and four insulated electrodes on the surface. The silicone gel was cured at a suitable temperature to form a flexible tube using molds fabricated by 3D printing technology. By applying differential voltages to the four electrodes of each IPMC rod-shaped actuator, MDOF bending motions of the active tube can be generated. Experimental results show that such IPMC-embedded tube designs can be used for developing robotic-assisted manipulation.

Active Tube-Shaped Actuator with Embedded Square Rod-Shaped Ionic Polymer-Metal Composites for Robotic-Assisted Manipulation

Science.gov (United States)

Liu, Jiayu; Zhu, Denglin; Chen, Hualing

2018-01-01

This paper reports a new technique involving the design, fabrication, and characterization of an ionic polymer-metal composite- (IPMC-) embedded active tube, which can achieve multidegree-of-freedom (MODF) bending motions desirable in many applications, such as a manipulator and an active catheter. However, traditional strip-type IPMC actuators are limited in only being able to generate 1-dimensional bending motion. So, in this paper, we try to develop an approach which involves molding or integrating rod-shaped IPMC actuators into a soft silicone rubber structure to create an active tube. We modified the Nafion solution casting method and developed a complete sequence of a fabrication process for rod-shaped IPMCs with square cross sections and four insulated electrodes on the surface. The silicone gel was cured at a suitable temperature to form a flexible tube using molds fabricated by 3D printing technology. By applying differential voltages to the four electrodes of each IPMC rod-shaped actuator, MDOF bending motions of the active tube can be generated. Experimental results show that such IPMC-embedded tube designs can be used for developing robotic-assisted manipulation. PMID:29770160

Four-Dimensional CT of the Diaphragm in Children: Initial Experience

Science.gov (United States)

2018-01-01

Objective To evaluate the technical feasibility of four-dimensional (4D) CT for the functional evaluation of the pediatric diaphragm. Materials and Methods In 22 consecutive children (median age 3.5 months, age range 3 days–3 years), 4D CT was performed to assess diaphragm motion. Diaphragm abnormalities were qualitatively evaluated and diaphragm motion was quantitatively measured on 4D CT. Lung density changes between peak inspiration and expiration were measured in the basal lung parenchyma. The diaphragm motions and lung density changes measured on 4D CT were compared between various diaphragm conditions. In 11 of the 22 children, chest sonography was available for comparison. Results Four-dimensional CT demonstrated normal diaphragm (n = 8), paralysis (n = 10), eventration (n = 3), and diffusely decreased motion (n = 1). Chest sonography demonstrated normal diaphragm (n = 2), paralysis (n = 6), eventration (n = 2), and right pleural effusion (n = 1). The sonographic findings were concordant with the 4D CT findings in 90.9% (10/11) of the patients. In diaphragm paralysis, the affected diaphragm motion was significantly decreased compared with the contralateral normal diaphragm motion (−1.1 ± 2.2 mm vs. 7.6 ± 3.8 mm, p = 0.005). The normal diaphragms showed significantly greater motion than the paralyzed diaphragms (4.5 ± 2.1 mm vs. −1.1 ± 2.2 mm, p Hounsfield units [HU] vs. 180 ± 71 HU, p = 0.03), while no significant differences were found between the normal diaphragms and the paralyzed diaphragms (136 ± 66 HU vs. 89 ± 73 HU, p = 0.1) or between the normal diaphragms and the contralateral normal diaphragms in paralysis (136 ± 66 HU vs. 180 ± 71 HU, p = 0.1). Conclusion The functional evaluation of the pediatric diaphragm is feasible with 4D CT in select children. PMID:29354007

Electromechanical performance of an ionic polymer–metal composite actuator with hierarchical surface texture

International Nuclear Information System (INIS)

He, Qingsong; Yu, Min; Zhang, Xiaoqing; Dai, Zhendong

2013-01-01

Two stainless steel templates were fabricated using electric-spark machining, and a hierarchical surface texture of ionic polymer was produced using both polishing and replication methods, which produced microscale and nanoscale groove-shaped microstructures at the surface of the polymer. The surface morphology of the Nafion membrane and metal electrode were observed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). SEM and EDS line-scan analysis indicated that the interfacial surface area was considerably increased and an excellent metal electrode was obtained with the production of a hierarchical surface texture. The displacement, blocking force, and electric current were measured using home-built apparatus. The results revealed that the combined polishing and replication method significantly improved the electromechanical performance of the ionic polymer–metal composite (IPMC). Compared with sandblasted Nafion-based IPMC, the blocking force, displacement, and electric current of the replicated Nafion-based IPMC were 4.39, 2.35, and 1.87 times higher, respectively. The IPMC fabricated in this work exhibited a competitive blocking force compared with recently reported actuators. (paper)

Chemical and structural changes at the ABS polymer-copper metal interface

NARCIS (Netherlands)

Kisin, S.; Scaltro, F.; Malanowski, P.; Varst, van der P.G.T.; With, de G.

2007-01-01

Creating oxygen containing moieties (hydroxyl or carbonyl) on polymer substrate surfaces is known to increase the adhesion strength of polymers to metals. However, we noticed adhesion increase with time even though no pre- or post-treatment of the polymer substrate was done. In the case of sputtered

Polymer-ceramic piezoelectric composites (PZT)

International Nuclear Information System (INIS)

Bassora, L.A.; Eiras, J.A.

1992-01-01

Polymer-ceramic piezoelectric transducers, with 1-3 of connectivity were prepared with different concentration of ceramic material. Piezoelectric composites, with equal electromechanical coupling factor and acoustic impedance of one third from that ceramic transducer, were obtained when the fractionary volume of PZT reach 30%. (C.G.C.)

Diaphragm users should follow 13 tips for best effectiveness.

Science.gov (United States)

Reese, M; Hatcher, R A

1984-11-01

The following 13 tips should be presented by family planning practitioners to diaphragm users: 1) the client must be able to feel her cervix; 2) the diaphragm should be checked for tears or holes before each use; 3) it should always be used with contraceptive jelly or cream; 4) petroleum products should not be used with the diaphragm; 5) the device should be inserted in plentyof time before intercourse; 6) it should be used at every intercourse; 7) to insert the diaphragm, use 1 hand to hold the cup down and the dome up, fold the diaphragm in half, push it toward the back of the vagina, and tuck the front rim behind the pubic bone; 8) check placement of the diaphragm by ensuring that the soft rubber dome covers the cervix and the front rim is firmly behind the pubic bone; 9) be aware that the diaphragm is probably not in the correct position if it causes discomfort; 10) do not douche with the diaphragm in place; 11) leave the device in place for a least 6 hours after intercourse; 12) remove the diaphragm by hooking the index finger behind the front rim and pulling down and out, being careful not to puncture the diaphragm; and 13) wash the diaphragm with mild soap and water and store it in a platic container away from heat. If patients gain or lose more than 10 pounds, have a pregnancy or pelvic surgery, suspect that their diaphragm is too large or too small, or are experiencing discomfort or pain, they should have the fit checked. Finally, since several cases of toxic shock syndrome have occured in diaphragm users, patients should avoid leaving the diaphragm in place more than 24 hours and avoid its use during menstruation.

Effect of Biomass Waste Filler on the Dielectric Properties of Polymer Composites

Directory of Open Access Journals (Sweden)

Yew Been Seok

2016-07-01

Full Text Available The effect of biomass waste fillers, namely coconut shell (CS and sugarcane bagasse (SCB on the dielectric properties of polymer composite was investigated. The aim of this study is to investigate the potential of CS and SCB to be used as conductive filler (natural source of carbon in the polymer composite. The purpose of the conductive filler is to increase the dielectric properties of the polymer composite. The carbon composition the CS and SCB was determine through carbon, hydrogen, nitrogen and sulphur (CHNS elemental analysis whereas the structural morphology of CS and SCB particles was examined by using scanning electron microscope. Room temperature open-ended coaxial line method was used to determine the dielectric constant and dielectric loss factor over broad band frequency range of 200 MHz-20 GHz. Based on this study, the results found that CS and SCB contain 48% and 44% of carbon, which is potentially useful to be used as conductive elements in the polymer composite. From SEM morphology, presence of irregular shape particles (size ≈ 200 μm and macroporous structure (size ≈ 2.5 μm were detected on CS and SCB. For dielectric properties measurement, it was measured that the average dielectric constant (ε' is 3.062 and 3.007 whereas the average dielectric loss factor (ε" is 0.282 and 0.273 respectively for CS/polymer and SCB/polymer composites. The presence of the biomass waste fillers have improved the dielectric properties of the polymer based composite (ε' = 2.920, ε" = 0.231. However, the increased in the dielectric properties is not highly significant, i.e. up to 4.86 % increase in ε' and 20% increase in ε". The biomass waste filler reinforced polymer composites show typical dielectric relaxation characteristic at frequency of 10 GHz - 20 GHz and could be used as conducting polymer composite for suppressing EMI at high frequency range.

Investigating accidents involving aircraft manufactured from polymer composite materials

OpenAIRE

Dunn, Leigh

2013-01-01

This thesis looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. ...

Atomic Origins of the Self-Healing Function in Cement–Polymer Composites

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Manh Thuong; Wang, Zheming; Rod, Kenton A.; Childers, Matthew I.; Fernandez, Carlos A.; Koech, Phillip K.; Bennett, Wendy D.; Rousseau, Roger J.; Glezakou, Vassiliki-Alexandra

2018-01-09

Motivated by recent advances in self-healing cement and epoxy polymer composites, we present a combined ab initio molecular dynamics and sum frequency generation (SFG) spectroscopy study of a calcium-silicate-hydrate/polymer interface. On stable, low-defect surfaces, the polymer only weakly adheres through coordination and hydrogen bonding interactions and can be easily mobilized towards defected surfaces. Conversely, on fractured surfaces, the polymer strongly anchors through ionic Ca-O bonds resulting from the deprotonation of polymer hydroxyl groups. In addition, polymer S-S groups are turned away from the cement/polymer interface, allowing for the self-healing function within the polymer. The overall elasticity and healing properties of these composites stem from a flexible hydrogen bonding network that can readily adapt to surface morphology. The theoretical vibrational signals associated with the proposed cement-polymer interfacial chemistry were confirmed experimentally by SFG spectroscopy.

Manufacturing Technology of Composite Materials-Principles of Modification of Polymer Composite Materials Technology Based on Polytetrafluoroethylene.

Science.gov (United States)

Panda, Anton; Dyadyura, Kostiantyn; Valíček, Jan; Harničárová, Marta; Zajac, Jozef; Modrák, Vladimír; Pandová, Iveta; Vrábel, Peter; Nováková-Marcinčínová, Ema; Pavelek, Zdeněk

2017-03-31

The results of the investigations into the technological formation of new wear-resistant polymer composites based on polytetrafluoroethylene (PTFE) filled with disperse synthetic and natural compounds are presented. The efficiency of using PTFE composites reinforced with carbon fibers depends on many factors, which influence the significant improvement of physicomechanical characteristics. The results of this research allow stating that interfacial and surface phenomena of the polymer-solid interface and composition play a decisive role in PTFE composites properties. Fillers hinder the relative movement of the PTFE molecules past one another and, in this way, reduce creep or deformation of the parts, reducing the wear rate of parts used in dynamic applications as well as the coefficient of thermal expansion. The necessary structural parameters of such polymer composites are provided by regimes of process equipment.

Effect of Polymer Matrix on the Structure and Electric Properties of Piezoelectric Lead Zirconatetitanate/Polymer Composites

Directory of Open Access Journals (Sweden)

Rui Li

2017-08-01

Full Text Available Piezoelectric lead zirconatetitanate (PZT/polymer composites were prepared by two typical polymer matrixes using the hot-press method. The micromorphology, microstructure, dielectric properties, and piezoelectric properties of the PZT/polymer composites were characterized and investigated. The results showed that when the condition of frequency is 103 Hz, the dielectric and piezoelectric properties of PZT/poly(vinylidene fluoride were both better than that of PZT/polyvinyl chloride (PVC. When the volume fraction of PZT was 50%, PZT/PVDF prepared by the hot-press method had better comprehensive electric property.

High Kinetic Energy Penetrator Shielding and High Wear Resistance Materials Fabricated with Boron Nitride Nanotubes (BNNTS) and BNNT Polymer Composites

Science.gov (United States)

Kang, Jin Ho (Inventor); Sauti, Godfrey (Inventor); Smith, Michael W. (Inventor); Jordan, Kevin C. (Inventor); Park, Cheol (Inventor); Bryant, Robert George (Inventor); Lowther, Sharon E. (Inventor)

2015-01-01

Boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNNPs), carbon nanotubes (CNTs), graphites, or combinations, are incorporated into matrices of polymer, ceramic or metals. Fibers, yarns, and woven or nonwoven mats of BNNTs are used as toughening layers in penetration resistant materials to maximize energy absorption and/or high hardness layers to rebound or deform penetrators. They can be also used as reinforcing inclusions combining with other polymer matrices to create composite layers like typical reinforcing fibers such as Kevlar.RTM., Spectra.RTM., ceramics and metals. Enhanced wear resistance and usage time are achieved by adding boron nitride nanomaterials, increasing hardness and toughness. Such materials can be used in high temperature environments since the oxidation temperature of BNNTs exceeds 800.degree. C. in air. Boron nitride based composites are useful as strong structural materials for anti-micrometeorite layers for spacecraft and space suits, ultra strong tethers, protective gear, vehicles, helmets, shields and safety suits/helmets for industry.

Highly ductile UV-shielding polymer composites with boron nitride nanospheres as fillers.

Science.gov (United States)

Fu, Yuqiao; Huang, Yan; Meng, Wenjun; Wang, Zifeng; Bando, Yoshio; Golberg, Dmitri; Tang, Chengchun; Zhi, Chunyi

2015-03-20

Polymer composites with enhanced mechanical, thermal or optical performance usually suffer from poor ductility induced by confined mobility of polymer chains. Herein, highly ductile UV-shielding polymer composites are successfully fabricated. Boron nitride (BN) materials, with a wide band gap of around ∼6.0 eV, are used as fillers to achieve the remarkably improved UV-shielding performance of a polymer matrix. In addition, it is found that spherical morphology BN as a filler can keep the excellent ductility of the composites. For a comparison, it is demonstrated that traditional fillers, including conventional BN powders can achieve the similar UV-shielding performance but dramatically decrease the composite ductility. The mechanism behind this phenomenon is believed to be lubricant effects of BN nanospheres for sliding of polymer chains, which is in consistent with the thermal analyses. This study provides a new design to fabricate UV-shielding composite films with well-preserved ductility.

Standard Guide for Testing Polymer Matrix Composite Materials

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This guide summarizes the application of ASTM standard test methods (and other supporting standards) to continuous-fiber reinforced polymer matrix composite materials. The most commonly used or most applicable ASTM standards are included, emphasizing use of standards of Committee D30 on Composite Materials. 1.2 This guide does not cover all possible standards that could apply to polymer matrix composites and restricts discussion to the documented scope. Commonly used but non-standard industry extensions of test method scopes, such as application of static test methods to fatigue testing, are not discussed. A more complete summary of general composite testing standards, including non-ASTM test methods, is included in the Composite Materials Handbook (MIL-HDBK-17). Additional specific recommendations for testing textile (fabric, braided) composites are contained in Guide D6856. 1.3 This guide does not specify a system of measurement; the systems specified within each of the referenced standards shall appl...

Liquid metals as electrodes in polymer light emitting diodes

NARCIS (Netherlands)

Andersson, G.G.; Gommans, H.H.P.; Denier van der Gon, A.W.; Brongersma, H.H.

2003-01-01

We demonstrate that liquid metals can be used as cathodes in light emitting diodes (pLEDs). The main difference between the use of liquid cathodes and evaporated cathodes is the sharpness of the metal–polymer interface. Liquid metal cathodes result in significantly sharper metal–organic interfaces

Microbuckling compression failure of a radiation-induced wood/polymer composite

International Nuclear Information System (INIS)

Boey, F.Y.C.

1990-01-01

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(±5)% and 90(±5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author)

Eventration of diaphragm with a rare association

Directory of Open Access Journals (Sweden)

Syed Shafiq

2014-01-01

Full Text Available Eventration of the diaphragm is a rare anomaly of unknown origin characterized by a permanent high position of one or rarely both the leaflets of the diaphragm, providing a potential space for the displacement of abdominal viscera on the affected side(s. The etiology, diagnosis, and management of this condition remains a controversial subject. We report a rare case of infiltrating squamous cell carcinoma of the esophagus in a patient with eventration of the diaphragm and gastric volvulus who presented to us with retrosternal discomfort. To the best of our knowledge, this rare association has not been reported in the literature, although one case of esophageal adenocarcinoma arising from Barrett′s esophagus in association with eventration of the diaphragm has been reported previously. This case again emphasis the varied associations of an eventration of the diaphragm.

Nanomodified polymer composites: Thermophysical and physico-mechanical properties

Science.gov (United States)

Shchegolkov, Alexander; Shchegolkov, Alexey; Dyachkova, Tatyana; Borovskikh, Pavel

2017-11-01

The paper presents the results of investigation of thermophysical and physicomechanical properties of polymer-based composites modified with paraffin and carbon nanotubes (CNTs) mixture. Thermal conductivity of composites based on polyethylene, fluoroplastic, polyvinyl chloride (PVC) is 0.48, 0.42 and 0.36 W/(m.°C), respectively, compared to thermal conductivity of pure paraffin - 0.25 W/(m.°C). It has been revealed that for materials heat capacity the polymer matrix determines the position of the maximum point on temperature dependence having extreme nature. Temperature changes in composites volume do not exceed 3% from the initial state to the phase transition, that allows them to be used in a combination with other materials.

Compositions, methods, and systems comprising fluorous-soluble polymers

Science.gov (United States)

Swager, Timothy M.; Lim, Jeewoo; Takeda, Yohei

2015-10-13

The present invention generally relates to compositions, methods, and systems comprising polymers that are fluorous-soluble and/or organize at interfaces between a fluorous phase and a non-fluorous phase. In some embodiments, emulsions or films are provided comprising a polymer. The polymers, emulsions, and films can be used in many applications, including for determining, treating, and/or imaging a condition and/or disease in a subject. The polymer may also be incorporated into various optoelectronic device such as photovoltaic cells, organic light-emitting diodes, organic field effect transistors, or the like. In some embodiments, the polymers comprise pi-conjugated backbones, and in some cases, are highly emissive.

Processing and properties of ceramic matrix-polymer composites for dental applications

Science.gov (United States)

Huang, Hsuan Yao

The basic composite structure of natural hard tissue was used to guide the design and processing of dental restorative materials. The design incorporates the methodology of using inorganic minerals as the main structural phase reinforced with a more ductile but tougher organic phase. Ceramic-polymer composites were prepared by slip casting a porous ceramic structure, heating and chemical treating the porous preform, infiltrating with monomer and then curing. The three factors that determined the mechanical properties of alumina-polymer composites were the type of polymer used, the method of silane treatments, and the type of bond between particles in the porous preforms. Without the use of silane coupling agents, the composites were measured to have a lower strength. The composite with a more "flexible" porous alumina network had a greater ability to plastically dissipate the energy of propagating cracks. However, the aggressive nature of the alumina particles on opposing enamel requires that these alumina-polymer composites have a wear compatible coating for practical application. A route to dense bioactive apatite wollastonite glass ceramics (AWGC)-polymer composites was developed. The problems associated with glass dissolution into the aqueous medium for slip casting were overcome with the use of silane. The role of heating rate and development of ceramic compact microstructure on composite properties was explored. In general, if isothermal heating was not applied, decreasing heating rate increased glass crystallinity and particle-particle fusion, but decreased pore volume. Also composite strength and fracture toughness decreased while modulus and hardness increased with decreasing heating rate. If isothermal heating was applied, glass crystallinity, pore content, and composite mechanical properties showed relatively little change regardless of the initial heating rate. The potential of AWGC-polymer composites for dental and implant applications was explored

Resin infusion of layered metal/composite hybrid and resulting metal/composite hybrid laminate

Science.gov (United States)

Cano, Roberto J. (Inventor); Grimsley, Brian W. (Inventor); Weiser, Erik S. (Inventor); Jensen, Brian J. (Inventor)

2009-01-01

A method of fabricating a metal/composite hybrid laminate is provided. One or more layered arrangements are stacked on a solid base to form a layered structure. Each layered arrangement is defined by a fibrous material and a perforated metal sheet. A resin in its liquid state is introduced along a portion of the layered structure while a differential pressure is applied across the laminate structure until the resin permeates the fibrous material of each layered arrangement and fills perforations in each perforated metal sheet. The resin is cured thereby yielding a metal/composite hybrid laminate.

Quickly updatable hologram images with high performance photorefractive polymer composites

Science.gov (United States)

Tsutsumi, Naoto; Kinashi, Kenji; Nonomura, Asato; Sakai, Wataru

2012-02-01

We present here quickly updatable hologram images using high performance photorefractive (PR) polymer composite based on poly(N-vinyl carbazole) (PVCz). PVCz is one of the pioneer materials for photoconductive polymer. PVCz/7- DCST/CzEPA/TNF (44/35/20/1 by wt) gives high diffraction efficiency of 68 % at E = 45 V/μm with fast response speed. Response speed of optical diffraction is the key parameter for real-time 3D holographic display. Key parameter for obtaining quickly updatable hologram images is to control the glass transition temperature lower enough to enhance chromophore orientation. Object image of the reflected coin surface recorded with reference beam at 532 nm (green beam) in the PR polymer composite is simultaneously reconstructed using a red probe beam at 642 nm. Instead of using coin object, object image produced by a computer was displayed on a spatial light modulator (SLM) is used as an object for hologram. Reflected object beam from a SLM interfered with reference beam on PR polymer composite to record a hologram and simultaneously reconstructed by a red probe beam. Movie produced in a computer was recorded as a realtime hologram in the PR polymer composite and simultaneously clearly reconstructed with a video rate.

The conductivity and stability of polymer composite solid electrolyte upon addition of graphene

Science.gov (United States)

Hamid, Farzana Abd.; Salleh, Fauzani Md.; Mohamed, Nor Sabirin

2017-12-01

The effect of graphene composition on the conductivity and stability of polymer composite solid electrolyte was studied. These polymer composite solid electrolytes were synthesized by sol gel method and prepared via the solution-casting technique. The compositions of graphene were varied between 10 wt% to 70 wt%. The changes in the functional group of polymer composite after the addition of graphene were characterized by Fourier Transform InfraRed spectroscopy. Electrochemical impedance spectroscopy was conducted at ambient temperature in the frequency range of 10 Hz to 1 MHz to study the conductivity of the polymer composite. The highest conductivity was obtained at 60 wt% graphene with the value of 2.85×10-4 Scm-1. Sample without the addition of graphene showed the lowest conductivity value of 1.77×10-7 Scm-1 and acts as an insulator. The high conductivity at 60 wt% graphene loading is related to dehydration of cellulose. This is supported by the FTIR spectrum where the absorption peaks of C-O stretching vibrations of polymer composite is weakened and the hydroxyl group is slightly shifted compared to the FTIR spectrum without the addition of graphene. Linear sweep voltammetry results demonstrated that the polymer composite solid electrolyte exhibited electrochemical stability up to 3.2 V.

Direct strain energy harvesting in automobile tires using piezoelectric PZT–polymer composites

International Nuclear Information System (INIS)

Van den Ende, D A; Van de Wiel, H J; Groen, W A; Van der Zwaag, S

2012-01-01

Direct piezoelectric strain energy harvesting can be used to power wireless autonomous sensors in environments where low frequency, high strains are present, such as in automobile tires during operation. However, these high strains place stringent demands on the materials with respect to mechanical failure or depolarization, especially at elevated temperatures. In this work, three kinds of ceramic–polymer composite piezoelectric materials were evaluated and compared against state-of-the-art piezoelectric materials. The new composites are unstructured and structured composites containing granular lead zirconate titanate (PZT) particles or PZT fibers in a polyurethane matrix. The composites were used to build energy harvesting patches which were attached to a tire and tested under simulated rolling conditions. The energy density of the piezoelectric ceramic–polymer composite materials is initially not as high as that of the reference materials (a macro-fiber composite and a polyvinylidene fluoride polymer). However, the area normalized power output of the composites after temperature and strain cycling is comparable to that of the reference devices because the piezoelectric ceramic–polymer composites did not degrade during operation. (paper)

3D Printing of Biocompatible Supramolecular Polymers and their Composites.

Science.gov (United States)

Hart, Lewis R; Li, Siwei; Sturgess, Craig; Wildman, Ricky; Jones, Julian R; Hayes, Wayne

2016-02-10

A series of polymers capable of self-assembling into infinite networks via supramolecular interactions have been designed, synthesized, and characterized for use in 3D printing applications. The biocompatible polymers and their composites with silica nanoparticles were successfully utilized to deposit both simple cubic structures, as well as a more complex twisted pyramidal feature. The polymers were found to be not toxic to a chondrogenic cell line, according to ISO 10993-5 and 10993-12 standard tests and the cells attached to the supramolecular polymers as demonstrated by confocal microscopy. Silica nanoparticles were then dispersed within the polymer matrix, yielding a composite material which was optimized for inkjet printing. The hybrid material showed promise in preliminary tests to facilitate the 3D deposition of a more complex structure.

Design recommendations for the optimized continuity diaphragm for prestressed concrete bulb-T beams.

Science.gov (United States)

2008-01-01

This research focused on prestressed concrete bulb-T (PCBT) beams made composite with a cast-in-place concrete deck and continuous over several spans through the use of continuity diaphragms. The current design procedure in AASHTO states that a conti...

Verification on reliability of diaphragm seal

International Nuclear Information System (INIS)

Ide, Hiroshi; Sakuta, Yoshiyuki; Hanawa, Yoshio; Tsuji, Tomoyuki; Tsuboi, Kazuaki; Nagao, Yoshiharu; Miyazawa, Masataka

2009-06-01

The main body of the JMTR is composed of reactor pressure vessel, core and reactor pool. At the bottom of the reactor pool, the Diaphragm-seal (2.6m outer diameter, 2m inner diameter, thickness 1.5mm) of the JMTR made of stainless steel is installed to prevent the water leak of the reactor pool and to absorb the expansion of the reactor pressure vessel due to pressure and temperature changes. In the long-term maintenance plans drawn up in 2004, it is required that the visual inspection for the diaphragm-seal should be carried out in 2007 and that the inspection should be carried out every around five-year. Therefore, prior to the refurbishment of the JMTR, the inspection device which is a deposition-collection apparatus with underwater-camera was developed, and the visual inspection was carried out to confirm the soundness of the diaphragm-seal. As a result, harmful flaws and/or corrosions were not inspected in the visual inspection, and the soundness of the diaphragm seal was confirmed. In future, the long-term integrity of the diaphragm-seal will could be achieved by conducting the periodic inspection. (author)

Addition of magnetic markers for non-destructive evaluation of polymer composites

Directory of Open Access Journals (Sweden)

Ana Paula Pereira Fulco

2011-12-01

Full Text Available Polymer composite pipes are an appealing option as a substitute for conventional steel pipes, particularly due to their inherent corrosion resistance. However, the composite pipes currently used do not allow non-destructive evaluation (NDE using instrumented devices which operate with magnetic sensors. The present work aims at the development of polymer composites with the addition magnetic markers to allow the application non-destructive evaluation techniques which use magnetic sensors. Glass-polyester composite flat, circular plates were fabricated with the addition of ferrite particles (barium ferrite and strontium ferrite and four types of notches were introduced on the plates' surfaces. The influence of these notches on the measured magnetic properties of each material was measured. X-ray diffraction (XRD, X-ray fluorescence (XRF and Brunauer, Emmett, and Teller (BET nitrogen adsorption were used for the characterization of the ferrite particles. Particle dispersion in the polymer matrix was analyzed by scanning electron microscopy (SEM. According to the results, a particular variation in magnetic field was detected over the region surrounding each type of notch. The results suggest that the proposed technique has great potential for damage detection in polymer composites using magnetic sensors and thus constitute a valuable contribution which may ultimately lead to the development of non-destructive evaluation techniques for assessing the structural integrity polymer composite pipes.

Basalt fiber reinforced polymer composites: Processing and properties

Science.gov (United States)

Liu, Qiang

A high efficiency rig was designed and built for in-plane permeability measurement of fabric materials. A new data derivation procedure to acquire the flow fluid pattern in the experiment was developed. The measurement results of the in-plane permeability for basalt twill 31 fabric material showed that a high correlation exists between the two principal permeability values for this fabric at 35% fiber volume fraction. This may be the most important scientific contribution made in this thesis. The results from radial measurements corresponded quite well with those from Unidirectional (UD) measurements, which is a well-established technique. No significant differences in mechanical properties were found between basalt fabric reinforced polymer composites and glass composites reinforced by a fabric of similar weave pattern. Aging results indicate that the interfacial region in basalt composites may be more vulnerable to environmental damage than that in glass composites. However, the basalt/epoxy interface may have been more durable than the glass/epoxy interface in tension-tension fatigue because the basalt composites have significantly longer fatigue life. In this thesis, chapter I reviews the literature on fiber reinforced polymer composites, with concentration on permeability measurement, mechanical properties and durability. Chapter II discusses the design of the new rig for in-plane permeability measurement, the new derivation procedure for monitoring of the fluid flow pattern, and the permeability measurement results. Chapter III compares the mechanical properties and durability between basalt fiber and glass fiber reinforced polymer composites. Lastly, chapter IV gives some suggestions and recommendations for future work.

Machining of Metal Matrix Composites

CERN Document Server

2012-01-01

Machining of Metal Matrix Composites provides the fundamentals and recent advances in the study of machining of metal matrix composites (MMCs). Each chapter is written by an international expert in this important field of research. Machining of Metal Matrix Composites gives the reader information on machining of MMCs with a special emphasis on aluminium matrix composites. Chapter 1 provides the mechanics and modelling of chip formation for traditional machining processes. Chapter 2 is dedicated to surface integrity when machining MMCs. Chapter 3 describes the machinability aspects of MMCs. Chapter 4 contains information on traditional machining processes and Chapter 5 is dedicated to the grinding of MMCs. Chapter 6 describes the dry cutting of MMCs with SiC particulate reinforcement. Finally, Chapter 7 is dedicated to computational methods and optimization in the machining of MMCs. Machining of Metal Matrix Composites can serve as a useful reference for academics, manufacturing and materials researchers, manu...

Micromechanics of Amorphous Metal/Polymer Hybrid Structures with 3D Cellular Architectures: Size Effects, Buckling Behavior, and Energy Absorption Capability.

Science.gov (United States)

Mieszala, Maxime; Hasegawa, Madoka; Guillonneau, Gaylord; Bauer, Jens; Raghavan, Rejin; Frantz, Cédric; Kraft, Oliver; Mischler, Stefano; Michler, Johann; Philippe, Laetitia

2017-02-01

By designing advantageous cellular geometries and combining the material size effects at the nanometer scale, lightweight hybrid microarchitectured materials with tailored structural properties are achieved. Prior studies reported the mechanical properties of high strength cellular ceramic composites, obtained by atomic layer deposition. However, few studies have examined the properties of similar structures with metal coatings. To determine the mechanical performance of polymer cellular structures reinforced with a metal coating, 3D laser lithography and electroless deposition of an amorphous layer of nickel-boron (NiB) is used for the first time to produce metal/polymer hybrid structures. In this work, the mechanical response of microarchitectured structures is investigated with an emphasis on the effects of the architecture and the amorphous NiB thickness on their deformation mechanisms and energy absorption capability. Microcompression experiments show an enhancement of the mechanical properties with the NiB thickness, suggesting that the deformation mechanism and the buckling behavior are controlled by the brittle-to-ductile transition in the NiB layer. In addition, the energy absorption properties demonstrate the possibility of tuning the energy absorption efficiency with adequate designs. These findings suggest that microarchitectured metal/polymer hybrid structures are effective in producing materials with unique property combinations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Immobilization of metals in contaminated soils using natural polymer-based stabilizers.

Science.gov (United States)

Tao, Xue; Li, Aimin; Yang, Hu

2017-03-01

Three low-cost natural polymer materials, namely, lignin (Ln), carboxymethyl cellulose, and sodium alginate, were used for soil amendment to immobilize lead and cadmium in two contaminated soil samples collected from a mining area in Nanjing, China. The remediation effects of the aforementioned natural polymers were evaluated by toxicity characteristic leaching procedure (TCLP) and sequential extractions. The stabilizers could lower the bioavailability of Pb and Cd in the contaminated soils, and the amount of the exchangeable forms of the aforementioned two metals were reduced evidently. TCLP results showed that the leaching concentrations of Pb and Cd were decreased by 5.46%-71.1% and 4.25%-49.6%, respectively, in the treated soils. The contents of the organic forms of the two metals both increased with the increase in stabilizer dose on the basis of the redistribution of metal forms by sequential extractions. These findings were due to the fact that the abundant oxygen-containing groups on the polymeric amendments were effective in chelating and immobilizing Pb and Cd, which have been further confirmed from the metal adsorptions in aqueous solutions. Moreover, Ln achieved the greatest effect among the three polymers under study because of the former's distinct three-dimensional molecular structure, showing the preferential immobilization of Pb over Cd in soils also. Thus, the above-mentioned natural polymers hold great application potentials for reducing metal ion entry into the food chain at a field scale. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance enhancement of quantum dot-sensitized solar cells based on polymer nano-composite catalyst

International Nuclear Information System (INIS)

Seo, Hyunwoong; Gopi, Chandu V.V.M.; Kim, Hee-Je; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu

2017-01-01

Highlights: •We studied polymer nano-composite containing TiO 2 nano-particles as a catalyst. •Polymer nano-composite was applied for quantum dot-sensitized solar cells. •Polymer nano-composite catalyst was considerably improved with TiO 2 nano-particles. •Polymer nano-composite showed higher photovoltaic performance than conventional Au. -- Abstract: Polymer nano-composite composed of poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) and TiO 2 nano-particles was deposited on fluorine-doped tin oxide substrate and applied as an alternative to Au counter electrode of quantum dot-sensitized solar cell (QDSC). It became surface-richer with the increase in nano-particle amount so that catalytic reaction was increased by widened catalytic interface. Electrochemical impedance spectroscopy and cyclic voltammetry clearly demonstrated the enhancement of polymer nano-composite counter electrode. A QDSC based on polymer nano-composite counter electrode showed 0.56 V of V OC , 12.24 mA cm −2 of J SC , 0.57 of FF, and 3.87% of efficiency and this photovoltaic performance was higher than that of QDSC based on Au counter electrode (3.75%).

Properties of polymer-silver nanocomposites fabricated by co-sputtering; Eigenschaften von Polymer-Silber-Nanokompositen hergestellt durch Co-Sputtern

Energy Technology Data Exchange (ETDEWEB)

Schuermann, Ulrich

2006-07-01

In this thesis polymer-metal nanocomposites were fabricated by simultaneous sputtering of silver and polymers from two independent magnetron sputtering sources. By the netted structure and the dielectric properties PTFE is suited for the use as matrix material. The metal content of the composite films was determined via the measurement of EDX intensities. The size of the nanoparticles was determined by means of TEM and XRD and lies in the range of 10 nm. The composite materials show at the percolation limit a sudden transition of the properties from polymer- to metal-like behaviour. The specific resistance decreases in a range between 35 and 40 % silver content by at least nine orders of magnitude. The optical properties change with the metal content. The absorption caused by plasmon resonance, which has at small filling degrees its maximum at about 000 nm and has an intense yellow colour of the composite material as consequence shifts with increasing silver content to longer wavelengths. The difference in the optical.behaviour of the nanocomposites and the pure polymers can be used for the fabrication of Bragg reflectors. Small changes in the metal content can in the polymer-silver nanocomposites in the range of the percolation threshold effect a drastic change in ther properties, by which applications as sensors are thinkable. [German] In dieser Arbeit wurden Polymer-Metall-Nanokomposite durch gleichzeitiges Sputtern von Silber und Polymeren aus zwei unabhaengigen Magnetron-Sputterquellen hergestellt. Durch die vernetzte Struktur und die dielektrischen Eigenschaften eignet sich PTFE zur Verwendung als Matrixmaterial. Der Metallgehalt der Kompositfilme wurde ueber die Messung von EDX-Intensitaeten ermittelt. Die Groesse der Nanopartikel wurde mit Hilfe von TEM und XRD bestimmt und liegt im Bereich von 10 nm. Die Kompositmaterialien zeigen an der Perkolationsgrenze einen schlagartigen Uebergang der Eigenschaften vom polymer- zum metallaehnlichen Verhalten. Der

Thermal Stresses Analysis and Optimized TTP Processes to Achieved CNT-Based Diaphragm for Thin Panel Speakers

Directory of Open Access Journals (Sweden)

Feng-Min Lai

2016-01-01

Full Text Available Industrial companies popularly used the powder coating, classing, and thermal transfer printing (TTP technique to avoid oxidation on the metallic surface and stiffened speaker diaphragm. This study developed a TTP technique to fabricate a carbon nanotubes (CNTs stiffened speaker diaphragm for thin panel speaker. The self-developed TTP stiffening technique did not require a high curing temperature that decreased the mechanical property of CNTs. In addition to increasing the stiffness of diaphragm substrate, this technique alleviated the middle and high frequency attenuation associated with the smoothing sound pressure curve of thin panel speaker. The advantage of TTP technique is less harmful to the ecology, but it causes thermal residual stresses and some unstable connections between printed plates. Thus, this study used the numerical analysis software (ANSYS to analyze the stress and thermal of work piece which have not delaminated problems in transfer interface. The Taguchi quality engineering method was applied to identify the optimal manufacturing parameters. Finally, the optimal manufacturing parameters were employed to fabricate a CNT-based diaphragm, which was then assembled onto a speaker. The result indicated that the CNT-based diaphragm improved the sound pressure curve smoothness of the speaker, which produced a minimum high frequency dip difference (ΔdB value.

Physico-chemical properties of modified inter-polymer complexes and composites

International Nuclear Information System (INIS)

Khafizov, M.M.

2004-01-01

Full text: Inter-polymer complexes (IC) are rather perspective and can occupy the important place in technology of materials, as find out a number of the most valuable properties. In essence, they are new polymeric materials with a complex of new qualities and operational characteristics. In the present work the influence of a nature and structure of cooperating components both on structure, and on properties of received final products is investigated. It is shown new opportunities of use of the IC for reception composite materials formed IC on the physical properties, rather close to amorphous compounds. The opportunity of reception polymeric composite materials with the given properties and structure is shown; the purposeful regulation of process of hardening inter-polymeric composite materials with disperse fillers of a various nature and contents is established. The properties of such composite materials are determined by amount of entered components, both their distribution and chemical nature of a filler, that allows to increase stability properties in 2.5-3 times. By using phenomenological analysis of the contact phenomena the differential equations are made which are used for the analysis of VAC sandwich-structures metal-IC-metal. In a range of voltage V=0 -1 -10 2 V the experimental VAC are described by dependences close to Ohmic J∼V n , n=1. It is shown that the presence of breaks σ=f(T) at temperature ∼ 300 K specifies on ionic character of conductivity of samples. The chemical resistance of inter-polymeric composites in relation to water, to a solution of NaCl and 'to aggressive environment' is comprehensively characterized. The optimum degree of filling of the fillers Cv=2-3 is determined at a specific surface of fillers 0.2-0.3 m 2 /g

“High-Throughput” Evaluation of Polymer-Supported Triazolic Appendages for Metallic Cations Extraction

Directory of Open Access Journals (Sweden)

Riadh Slimi

2015-03-01

Full Text Available The aim of this work was to find and use a low-cost high-throughput method for a quick primary evaluation of several metal extraction by substituted piperazines appendages as chelatants grafted onto Merrifield polymer using click-chemistry by the copper (I-catalyzed Huisgen’s reaction (CuAAC The polymers were tested for their efficiency to remove various metal ions from neutral aqueous solutions (13 cations studied: Li+, Na+, K+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Cd2+, Ba2+, Ce3+, Hg+ and Pb2+ using the simple conductimetric measurement method. The polymers were found to extract all metals with low efficiencies ≤40%, except for Fe3+ and Hg+, and sometimes Pb2+. Some polymers exhibited a selectively for K+, Cd2+ and Ba2+, with good efficiencies. The values obtained here using less polymer, and a faster method, are in fair correspondence (average difference ±16% with another published evaluation by atomic absorption spectroscopy (AAS.

New Method for the Development of Plasmonic Metal-Semiconductor Interface Layer: Polymer Composites with Reduced Energy Band Gap

Directory of Open Access Journals (Sweden)

Shujahadeen B. Aziz

2017-01-01

Full Text Available Silver nanoparticles within a host polymer of chitosan were synthesized by using in situ method. Ultraviolet-visible spectroscopy was then carried out for the prepared chitosan : silver triflate (CS : AgTf samples, showing a surface plasmonic resonance (SPR peak at 420 nm. To prepare polymer composites with reduced energy band gap, different amounts of alumina nanoparticles were incorporated into the CS : AgTf solution. In the present work, the results showed that the reduced silver nanoparticles and their adsorption on wide band gap alumina (Al2O3 particles are an excellent approach for the preparation of polymer composites with small optical band gaps. The optical dielectric loss parameter has been used to determine the band gap experimentally. The physics behind the optical dielectric loss were interpreted from the viewpoint of quantum mechanics. From the quantum-mechanics viewpoint, optical dielectric loss was also found to be a complex equation and required lengthy numerical computation. From the TEM investigation, the adsorption of silver nanoparticles on alumina has been observed. The optical micrograph images showed white spots (silver specks with different sizes on the surface of the films. The second semicircle in impedance Cole-Cole plots was found and attributed to the silver particles.

Solid particle erosion of polymers and composites

Science.gov (United States)

Friedrich, K.; Almajid, A. A.

2014-05-01

After a general introduction to the subject of solid particle erosion of polymers and composites, the presentation focusses more specifically on the behavior of unidirectional carbon fiber (CF) reinforced polyetheretherketone (PEEK) composites under such loadings, using different impact conditions and erodents. The data were analyzed on the basis of a newly defined specific erosive wear rate, allowing a better comparison of erosion data achieved under various testing conditions. Characteristic wear mechanisms of the CF/PEEK composites consisted of fiber fracture, matrix cutting and plastic matrix deformation, the relative contribution of which depended on the impingement angles and the CF orientation. The highest wear rates were measured for impingement angles between 45 and 60°. Using abrasion resistant neat polymer films (in this case PEEK or thermoplastic polyurethane (TPU) ones) on the surface of a harder substrate (e.g. a CF/PEEK composite plate) resulted in much lower specific erosive wear rates. The use of such polymeric films can be considered as a possible method to protect composite surfaces from damage caused by minor impacts and erosion. In fact, they are nowadays already successfully applied as protections for wind energy rotor blades.

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femorotibial (uni-compartmental) metal... Devices § 888.3535 Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis. (a) Identification. A knee joint femorotibial (uni-compartmental) metal/polymer porous-coated...

Polymer-metal hybrid transparent electrodes for flexible electronics

Science.gov (United States)

Kang, Hongkyu; Jung, Suhyun; Jeong, Soyeong; Kim, Geunjin; Lee, Kwanghee

2015-03-01

Despite nearly two decades of research, the absence of ideal flexible and transparent electrodes has been the largest obstacle in realizing flexible and printable electronics for future technologies. Here we report the fabrication of ‘polymer-metal hybrid electrodes’ with high-performance properties, including a bending radius 95% and a sheet resistance solar cells that exhibit a high power conversion efficiency of 10% and polymer light-emitting diodes that can outperform those based on transparent conducting oxides.

Preparation of polymers suitable for radiation shielding and studying its properties (polyester composites with heavy metals salts)

International Nuclear Information System (INIS)

Kharita, M. H.; Al-Ajji, Z.; Yousef, S.

2010-12-01

Four composites were prepared in this work, based on polyester and heavy metals oxides and salts. The attenuation properties, as well as mechanical properties were studied, and the chemical stability was evaluated. It has been shown, that these composites can be used in radiation shielding for X-rays successfully, and the exact composition of these composites can be optimized according to the radiation energy to prepare the lightest possible shield. (author)

21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer constrained cemented or... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint... replace a hip joint. The device prevents dislocation in more than one anatomic plane and has components...

Solid polymer electrolyte composite membrane comprising plasma etched porous support

Science.gov (United States)

Liu, Han; LaConti, Anthony B.

2010-10-05

A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

Solid polymer electrolyte composite membrane comprising laser micromachined porous support

Science.gov (United States)

Liu, Han [Waltham, MA; LaConti, Anthony B [Lynnfield, MA; Mittelsteadt, Cortney K [Natick, MA; McCallum, Thomas J [Ashland, MA

2011-01-11

A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

Thermosetting Polymer-Matrix Composites for Strucutral Repair Applications

Energy Technology Data Exchange (ETDEWEB)

Goertzen, William Kirby [Iowa State Univ., Ames, IA (United States)

2007-12-01

Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporate of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.

Study of optical properties of Erbium doped Tellurite glass-polymer composite

Science.gov (United States)

Sushama, D.

2014-10-01

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er2O3 doped TeO2-WO3-La2O3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

Polymer-Ceramic Composite Materials for Pyroelectric Infrared Detectors: An Overview

Science.gov (United States)

Aggarwal, M. D; Currie, J. R.; Penn, B. G.; Batra, A. K.; Lal, R. B.

2007-01-01

Ferroelectrics:Polymer composites can be considered an established substitute for conventional electroceramics and ferroelectric polymers. The composites have a unique blend of polymeric properties such as mechanical flexibility, high strength, formability, and low cost, with the high electro-active properties of ceramic materials. They have attracted considerable interest because of their potential use in pyroelectric infrared detecting devices and piezoelectric transducers. These flexible sensors and transducers may eventually be useful for their health monitoring applications for NASA crew launch vehicles and crew exploration vehicles being developed. In the light of many technologically important applications in this field, it is worthwhile to present an overview of the pyroelectric infrared detector theory, models to predict dielectric behavior and pyroelectric coefficient, and the concept of connectivity and fabrication techniques of biphasic composites. An elaborate review of Pyroelectric-Polymer composite materials investigated to date for their potential use in pyroelectric infrared detectors is presented.

Sol-gel derived polymer composites for energy storage and conversion

Science.gov (United States)

Han, Kuo

Sol-gel process is a simple chemistry to convert the small precursor molecules into an inorganic polymer, which could be applied to synthesize inorganic materials, modify the interface of materials, bridge the organic and inorganic materials, etc. In this dissertation, novel sol-gel derived composites have been developed for high dielectric breakdown capacitors, low high frequency loss capacitors and flexible piezoelectrics. Numerous efforts have been made in the past decades to improve the energy storage capability of composite materials by incorporating nanometer scale ceramic addictives with high dielectric permittivity into dielectric polymers with high breakdown strength. However, most composites suffer from the low breakdown strength and make the potential gain in energy density small. Here, a new chemical strategy is proposed that, through sol-gel reactions between ceramic precursors and functional groups at the end of the functionalized Poly(vinylidene fluoride -co-chlorotrifluoroethylene) chains, amorphous low permittivity ceramics was in-situ generated in the polymer matrix and cross-linked the polymer chains simultaneously. By carefully tuning precursors, the polymer/precursors feeding ratios, a series of nanocomposites were systematically designed. All the samples are comprehensively characterized and the structure-property correlations are well investigated. The optimal samples exhibit higher breakdown strength than the pristine polymer. The enhanced breakdown strength ascribed to low contrast in permittivity, great dispersion and improved electrical and mechanical properties. This newly developed approach has shown great promise for new composite capacitors. The percolative polymer composites have recently exhibited great potential in energy storage due to their high dielectric permittivities at the neighborhood of the percolation threshold. Yet high energy dissipation and poor voltage endurance of the percolative composites resulted from electrical

To detect anomalies in diaphragm walls

NARCIS (Netherlands)

Spruit, R.

2015-01-01

Diaphragm walls are potentially ideal retaining walls for deep excavations in densely built-up areas, as they cause no vibrations during their construction and provide structural elements with high strength and stiffness. In the recent past, however, several projects using diaphragm walls as soil

A novel polymer nanotube composite for photovoltaic packaging applications

International Nuclear Information System (INIS)

Ravichandran, J; Manna, I; Manoj, A G; Liu, J; Carroll, D L

2008-01-01

Packaging of organic photovoltaic (OPV) devices is an important issue which has been rarely addressed in the past. With the recent reports of high efficiency organic photovoltaics (6%), the need to produce materials which can effectively protect the device from degradation due to exposure to oxygen, moisture and radiation is pressing. We report a novel Saran (a co-polymer of vinylidene chloride and acrylonitrile) based polymer nanotube composite, which shows high transparency in the visible region, good barrier properties and thermal stability, for use as an encapsulant for OPV devices. Different loadings of Saran and boron nitride nanotubes were taken and the composites were prepared to optimize the composition of the composite. UV-visible spectroscopy, infra-red spectroscopy and thermal analysis were used to characterize the composite. The barrier properties of the composite were tested on poly(3-hexylthiophene), which is used in high efficiency OPV devices

Congenital duodenal diaphragm in eight children

International Nuclear Information System (INIS)

Nawaz, Akhtar; Matta, Hilal; Jacobsz, Alic; Al-Salem, Ahmad H.; Trad, Omar

2004-01-01

Congenital duodenal obstruction (CDO) is common and usually easy to diagnose cause of intestinal obstruction in the newborn, except when the cause of the obstruction is duodenal diaphragm. We describe our experience with eight children who had intrinsic duodenal obstruction secondary to a duodenal diaphragm. The medical record of 22 children with the diagnosis of congenital intrinsic duodenal were reviewed for age, sex, gestation, birth weight, clinical features, associated anomalies, method of diagnosis, treatment and outcome. Operative findings and procedures were obtained from the operative notes. Eight of 22 children (36.4%) had congenital duodenal diaphragm (CDD). In all children, the diagnosis was made from the plain abdominal X-ray, which showed the classic double-bubble appearence, and barium meal, which showed duodenal obstruction. Four patients had associated anomalies, including two with Down's syndrome intraoperatively, five patients were found to have duodenal diaphragm with a central hole, while the other three had complete duodenal diaphragms. Postoperatively, all patients did well. Six required total parenteral nutrition. The 100% survival rate among these children is comparable to that in Western countries, and can be attributed to the lack of major associated abnormalities, good perioperative management, and the availability of total parenteral nutrition. (author)

Plasma coatings of nitrogen polymers on metal prostheses of the circulatory system

International Nuclear Information System (INIS)

Gomez J, L. M.

2016-01-01

This work has a study about the synthesis of poly aniline, poly allylamine and poly pyrrole doped with iodine onto metallic surfaces similar to stents for the circulatory system. Ar, water and hydrogen peroxide plasmas were used for eroding, conditioning and synthesizing polymers that potentially reduce some rejection reactions when stents are implanted in the human body. Stents are small metallic meshes that applied inside collapsed arteries or veins enlarge the diameter and restore the blood flow, however the metallic surfaces usually cause rejection reactions that obstruct the veins again. To give solutions to this problem, in this work is studied the synthesis of biocompatible polymer coatings on the stents that resist the blood flow forming a biocompatible interface between metal and blood. The metallic substrates were eroded and chemically prepared with Ar, H_2O and/or H_2O_2 glow discharges on which the polymers were synthesized by plasma. The coatings were morphologically characterized by optical, scanning electron and atomic force microscopy, the chemical structure was studied by infrared and photoelectron X-ray spectroscopy. The hydrophilicity was studied measuring the advance static contact angle and the adhesion was evaluated indirectly with scanning electron microscopy after two months submerged in buffered phosphate solutions. The results indicate that the polymers grew following the superficial morphology; that the conditioning with Ar ions erode the substrates and that the conditioning with H_2O or H_2O_2 erodes and activates the surface generating oxygen bridges which help in the polymer-metal adhesion. The chemical structure of the polymeric coatings contain crosslinked structures that correspond to links between monomers with the participation of all atoms, states that suggest monomer fragmentation and oxidation and states that indicate oxygen bridges in the polymers. The coatings had contact angles close to 90 degrees where is located the line

Method of production of a diaphragm for instruments in particle optics and diaphragm fabricated by this method

International Nuclear Information System (INIS)

Sandrik, J.; Krohne, P.

1975-01-01

The production method of, e.g., a circular diaphragm for an electron microscope is based on copper plate as supporting material. A light-sensitive, electrically insulating layer is coated on this. After exposing and freeing the positions of this layer, e.g., the circular interior as well as the cross-piece to the exterior of the diaghragm, a galvanic building-up of a noble metal layer follows, e.g. gold, on these now free positions. After freeing the remaining non-exposed material, an etching-protective lacquer is coated on the positions of the supporting material which are to be maintained. The remaining parts of the supporting material are then removed by positive etching. (DG/LH) [de

Chemical metallization of KMPR photoresist polymer in aqueous solutions

Science.gov (United States)

Zeb, Gul; Duong, Xuan Truong; Vu, Ngoc Pi; Phan, Quang The; Nguyen, Duc Tuong; Ly, Viet Anh; Salimy, Siamak; Le, Xuan Tuan

2017-06-01

While conventional methods for preparing thin films of metals and metallic alloys on insulating substrates in the field of microelectromechanical systems (MEMS) include vapor deposition techniques, we demonstrate here that electroless deposition can be considered as an alternate efficient approach to metallize the surface of insulating substrates, such as KMPR epoxy photoresist polymer. In comparison with the physical and chemical vapor deposition methods, which are well-established for metallization of photoresist polymers, our electroless nickel plating requires only immersing the substrates into aqueous solutions in open air at low temperatures. Thin films of nickel alloy have been deposited electrolessly on KMPR surface, through a cost-effective and environmental chromium-free process, mediated through direct grafting of amine palladium complexes in aqueous medium. This covalent organic coating provides excellent adhesion between KMPR and the nickel film and allows better control of the palladium catalyst content. Covalent grafting and characterization of the deposited nickel film have been carried out by means of Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy techniques.

A study of TiN-coated metal-on-polymer bearing materials for hip prosthesis

Science.gov (United States)

Lee, Sung Bai; Choi, Jin Young; Park, Won Woong; Jeon, Jun Hong; Won, Sung Ok; Byun, Ji Young; Lim, Sang Ho; Han, Seung Hee

2010-08-01

The TiN-coated metal-on-polymer hip prosthetic pair has the potential to reduce wear debris of UHMWPE (ultra-high molecular weight polyethylene) and to prevent metallic-ion-induced cytotoxicity. However, high quality and adherent film is a key to the clinical success of hip prostheses. In this study, titanium nitride (TiN) films were deposited on stainless steel using plasma immersion ion implantation & deposition (PIII&D) technique to create high-quality film and an adherent interface. The chemical state and composition were analyzed by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and energy dispersive spectroscopy (EDS). The mechanical properties of the films were characterized using a micro-hardness tester and a pin-on-disk wear tester, and an x-ray diffractometer (XRD) was used for a crystallographic analysis. The PIII&D-treated TiN films showed a stoichiometric and (200) preferred orientation and micro-hardness up to 150 % higher than untreated film. A TiN-coated specimen using the PIII&D process also showed less UHMWPE wear compared to untreated specimens. The volumetric wear rate of UHMWPE could be reduced by as much as 42 % compared to when Co-Cr alloy was used. The results of this study show that advanced TiN-coating via the PIII&D process is a viable means of reducing UHMWPE wear in the metal-on-polymer bearing couple.

Molecular and structural properties of polymer composites filled with activated charcoal particles

Energy Technology Data Exchange (ETDEWEB)

Tahir, Dahlang, E-mail: dtahir@fmipa.unhas.ac.id; Bakri, Fahrul [Department of Physics, Hasanuddin University, Makassar 90245 Indonesia (Indonesia); Liong, Syarifuddin [Department of Chemistry, Hasanuddin University, Makassar 90245 Indonesia (Indonesia)

2016-03-11

We have studied the molecular properties, structural properties, and chemical composition of composites by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, and X-ray fluorescence (XRF) spectroscopy, respectively. FTIR spectra shows absorption band of hydroxyl group (-OH), methyl group (-CH{sub 3}) and aromatic group (C-C). The absorption band for aromatic group (C-C) shows the formation of carbonaceous in composites. XRF shows chemical composition of composites, which the main chemicals are SO{sub 3}, Cl, and ZnO. The loss on ignition value (LOI) of activated charcoal indicates high carbonaceous matter. The crystallite size for diffraction pattern from hydrogel polymer is about 17 nm and for activated charcoal are about 19 nm. The crystallite size of the polymer is lower than that of activated charcoal, which make possible of the particle from filler in contact with each other to form continuous conducting polymer through polymer matrix.

High field dielectric properties of anisotropic polymer-ceramic composites

International Nuclear Information System (INIS)

Tomer, V.; Randall, C. A.

2008-01-01

Using dielectrophoretic assembly, we create anisotropic composites of BaTiO 3 particles in a silicone elastomer thermoset polymer. We study a variety of electrical properties in these composites, i.e., permittivity, dielectric breakdown, and energy density as function of ceramic volume fraction and connectivity. The recoverable energy density of these electric-field-structured composites is found to be highly dependent on the anisotropy present in the system. Our results indicate that x-y-aligned composites exhibit higher breakdown strengths along with large recoverable energy densities when compared to 0-3 composites. This demonstrates that engineered anisotropy can be employed to control dielectric breakdown strengths and nonlinear conduction at high fields in heterogeneous systems. Consequently, manipulation of anisotropy in high-field dielectric properties can be exploited for the development of high energy density polymer-ceramic systems

Materials for Slack Diaphragms

Science.gov (United States)

Puschmann, Traute

1940-01-01

This report deals with systematic experiments carried out on five diaphragm materials with different pretreatment, for the purpose of ascertaining the suitability of such materials for slack diaphragms. The relationship of deflection and load, temperature and moisture, was recorded. Of the explored materials, synthetic leather, balloon cloth, goldbeaters skin, Igelit and Buna, synthetic leather treated with castor oil is the most suitable material for the small pressure range required. Balloon cloth is nearly as good, while goldbeaters skin, Igelit and Buna were found to be below the required standards.

Synthesis and characterization of metal ion-imprinted polymers

Indian Academy of Sciences (India)

2018-03-29

Mar 29, 2018 ... polymers (CPs) were synthesized through the same method without using metal ion. Characterization of the ... tizanidine obtained from MMIP-NPs showed that signifi- .... C=C vari- able alkene stretching band at 1636 cm. −1.

Study of optical properties of Erbium doped Tellurite glass-polymer composite

Energy Technology Data Exchange (ETDEWEB)

Sushama, D., E-mail: sushasukumar@gmail.com [Research Awardee, LAMP, Dept. of Physics, Nit, Calicut, India and Dept. of Physics, M.S.M. College, Kayamkulam, Kerala (India)

2014-10-15

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er{sub 2}O{sub 3} doped TeO{sub 2}‐WO{sub 3}‐La{sub 2}O{sub 3} Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

Study of optical properties of Erbium doped Tellurite glass-polymer composite

International Nuclear Information System (INIS)

Sushama, D.

2014-01-01

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er 2 O 3 doped TeO 2 ‐WO 3 ‐La 2 O 3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption

On Healable Polymers and Fiber-Reinforced Composites

Science.gov (United States)

Nielsen, Christian Eric

Polymeric materials capable of healing damage would be valuable in structural applications where access for repair is limited. Approaches to creating such materials are reviewed, with the present work focusing on polymers with thermally reversible covalent cross-links. These special cross-links are Diels-Alder (DA) adducts, which can be separated and re-formed, enabling healing of mechanical damage at the molecular level. Several DA-based polymers, including 2MEP4FS, are mechanically and thermally characterized. The polymerization reaction of 2MEP4FS is modeled and the number of established DA adducts is associated with the glass transition temperature of the polymer. The models are applied to concentric cylinder rotational measurements of 2MEP4FS prepolymer at room and elevated temperatures to describe the viscosity as a function of time, temperature, and conversion. Mechanical damage including cracks and scratches are imparted in cured polymer samples and subsequently healed. Damage due to high temperature thermal degradation is observed to not be reversible. The ability to repair damage without flowing polymer chains makes DA-based healable polymers particularly well-suited for crack healing. The double cleavage drilled compression (DCDC) fracture test is investigated as a useful method of creating and incrementally growing cracks in a sample. The effect of sample geometry on the fracture behavior is experimentally and computationally studied. Computational and empirical models are developed to estimate critical stress intensity factors from DCDC results. Glass and carbon fiber-reinforced composites are fabricated with 2MEP4FS as the matrix material. A prepreg process is developed that uses temperature to control the polymerization rate of the monomers and produce homogeneous prepolymer for integration with a layer of unidirectional fiber. Multiple prepreg layers are laminated to form multi-layered cross-ply healable composites, which are characterized in

Ultrasonographic Assessment of Diaphragm Function in Critically Ill Subjects.

Science.gov (United States)

Umbrello, Michele; Formenti, Paolo

2016-04-01

The majority of patients admitted to the ICU require mechanical ventilation as a part of their process of care. However, mechanical ventilation itself or the underlying disease can lead to dysfunction of the diaphragm, a condition that may contribute to the failure of weaning from mechanical ventilation. However, extended time on the ventilator increases health-care costs and greatly increases patient morbidity and mortality. Nevertheless, symptoms and signs of muscle disease in a bedridden (or bed rest-only) ICU patient are often difficult to assess because of concomitant confounding factors. Conventional assessment of diaphragm function lacks specific, noninvasive, time-saving, and easily performed bedside tools or requires patient cooperation. Recently, the use of ultrasound has raised great interest as a simple, noninvasive method of quantification of diaphragm contractile activity. In this review, we discuss the physiology and the relevant pathophysiology of diaphragm function, and we summarize the recent findings concerning the evaluation of its (dys)function in critically ill patients, with a special focus on the role of ultrasounds. We describe how to assess diaphragm excursion and diaphragm thickening during breathing and the meaning of these measurements under spontaneous or mechanical ventilation as well as the reference values in health and disease. The spread of ultrasonographic assessment of diaphragm function may possibly result in timely identification of patients with diaphragm dysfunction and to a potential improvement in the assessment of recovery from diaphragm weakness. Copyright © 2016 by Daedalus Enterprises.

A 3D-Printable Polymer-Metal Soft-Magnetic Functional Composite—Development and Characterization

Directory of Open Access Journals (Sweden)

Bilal Khatri

2018-01-01

Full Text Available In this work, a 3D printed polymer–metal soft-magnetic composite was developed and characterized for its material, structural, and functional properties. The material comprises acrylonitrile butadiene styrene (ABS as the polymer matrix, with up to 40 vol. % stainless steel micropowder as the filler. The composites were rheologically analyzed and 3D printed into tensile and flexural test specimens using a commercial desktop 3D printer. Mechanical characterization revealed a linearly decreasing trend of the ultimate tensile strength (UTS and a sharp decrease in Young’s modulus with increasing filler content. Four-point bending analysis showed a decrease of up to 70% in the flexural strength of the composite and up to a two-factor increase in the secant modulus of elasticity. Magnetic hysteresis characterization revealed retentivities of up to 15.6 mT and coercive forces of up to 4.31 kA/m at an applied magnetic field of 485 kA/m. The composite shows promise as a material for the additive manufacturing of passive magnetic sensors and/or actuators.

Conducting polymer/carbon nanocoil composite electrodes for efficient supercapacitors

KAUST Repository

Baby, Rakhi Raghavan

2012-01-01

Herein, we report for the first time, conducting polymer (polyaniline (PANI) and polypyrrole (PPY)) coated carbon nanocoils (CNCs) as efficient binder-free electrode materials for supercapacitors. CNCs act as a perfect backbone for the uniform distribution of the conducting polymers in the composites. In two electrode configuration, the samples exhibited high specific capacitance with the values reaching up to 360 and 202 F g -1 for PANI/CNCs and PPY/CNCs respectively. The values obtained for specific capacitance and maximum storage energy per unit mass of the composites were found to be comparable to one of the best reported values for polymer coated multi-walled carbon nanotubes. In addition, the fabricated PANI/CNC based supercapacitors exhibited a high value of 44.61 Wh kg -1 for maximum storage energy per unit mass. Although the devices exhibit an initial capacitance loss due to the instability of the polymer, the specific capacitance stabilizes at a fixed value after 500 charge-discharge cycles. © 2012 The Royal Society of Chemistry.

Electrochemistry of conductive polymers 39. Contacts between conducting polymers and noble metal nanoparticles studied by current-sensing atomic force microscopy.

Science.gov (United States)

Cho, Shin Hyo; Park, Su-Moon

2006-12-28

Electrical properties of contacts formed between conducting polymers and noble metal nanoparticles have been examined using current-sensing atomic force microscopy (CS-AFM). Contacts formed between electrochemically prepared pi-conjugated polymer films such as polypyrrole (PPy), poly(3-methylthiophene) (P3MeT), as well as poly(3,4-ethylenedioxythiophene) (PEDOT) and noble metal nanoparticles including platinum (Pt), gold (Au), and silver (Ag) have been examined. The Pt nanoparticles were electrochemically deposited on a pre-coated PPy film surface by reducing a platinum precursor (PtCl62-) at a constant potential. Both current and scanning electron microscopic images of the film showed the presence of Pt islands. The Au and Ag nanoparticles were dispersed on the P3MeT and PEDOT film surfaces simply by dipping the polymer films into colloid solutions containing Au or Ag particles for specified periods (5 to approximately 10 min). The deposition of Au or Ag particles resulted from either their physical adsorption or chemical bonding between particles and the polymer surface depending on the polymer. When compared with PPy, P3MeT and PEDOT showed a stronger binding to Au or Ag nanoparticles when dipped in their colloidal solutions for the same period. This indicates that Au and Ag particles are predominantly linked with the sulfur atoms via chemical bonding. Of the two, PEDOT was more conductive at the sites where the particles are connected to the polymer. It appears that PEDOT has better aligned sulfur atoms on the surface and is strongly bonded to Au and Ag nanoparticles due to their strong affinity to gold and silver. The current-voltage curves obtained at the metal islands demonstrate that the contacts between these metal islands and polymers are ohmic.

General overview of graphene: Production, properties and application in polymer composites

International Nuclear Information System (INIS)

Phiri, Josphat; Gane, Patrick; Maloney, Thad C.

2017-01-01

Highlights: • Three aspects of graphene have been reviewed: properties, fabrication and polymer composites. • Scalability potential of graphite based exfoliation methods is discussed. • Graphene produced via GO and LPE methods is compared in polymer composite applications. - Abstract: Graphene is a new and exciting material that has attracted much attention in the last decade and is being extensively explored because of its properties, which have been described with so many superlatives. Production of graphene for large scale application is still a major challenge. Top-down graphene exfoliation methods from graphite, such as liquid-phase exfoliation which is promising because of low cost and high scalability potential will be briefly discussed. We also analyze the challenges and possibilities of using graphene as a nanofiller in polymer composites which has resulted in enhanced electrical, mechanical and thermal properties. In this review, we take a panoramic approach to give insight on the different aspects of graphene such as properties, graphite-based production methods and also examples of graphene application in polymer composites and which will be beneficial to both novice and experts.

General overview of graphene: Production, properties and application in polymer composites

Energy Technology Data Exchange (ETDEWEB)

Phiri, Josphat, E-mail: josphat.phiri@aalto.fi [School of Chemical Technology, Department of Forest Products Technology, Aalto University, P.O. Box 16300, 00076 Aalto (Finland); Gane, Patrick [School of Chemical Technology, Department of Forest Products Technology, Aalto University, P.O. Box 16300, 00076 Aalto (Finland); Omya International AG, CH-4665 Oftringen (Switzerland); Maloney, Thad C., E-mail: thaddeus.maloney@aalto.fi [School of Chemical Technology, Department of Forest Products Technology, Aalto University, P.O. Box 16300, 00076 Aalto (Finland)

2017-01-15

Highlights: • Three aspects of graphene have been reviewed: properties, fabrication and polymer composites. • Scalability potential of graphite based exfoliation methods is discussed. • Graphene produced via GO and LPE methods is compared in polymer composite applications. - Abstract: Graphene is a new and exciting material that has attracted much attention in the last decade and is being extensively explored because of its properties, which have been described with so many superlatives. Production of graphene for large scale application is still a major challenge. Top-down graphene exfoliation methods from graphite, such as liquid-phase exfoliation which is promising because of low cost and high scalability potential will be briefly discussed. We also analyze the challenges and possibilities of using graphene as a nanofiller in polymer composites which has resulted in enhanced electrical, mechanical and thermal properties. In this review, we take a panoramic approach to give insight on the different aspects of graphene such as properties, graphite-based production methods and also examples of graphene application in polymer composites and which will be beneficial to both novice and experts.

The effect of water on thermal stresses in polymer composites

Science.gov (United States)

Sullivan, Roy M.

1994-01-01

The fundamentals of the thermodynamic theory of mixtures and continuum thermochemistry are reviewed for a mixture of condensed water and polymer. A specific mixture which is mechanically elastic with temperature and water concentration gradients present is considered. An expression for the partial pressure of water in the mixture is obtained based on certain assumptions regarding the thermodynamic state of the water in the mixture. Along with a simple diffusion equation, this partial pressure expression may be used to simulate the thermostructural behavior of polymer composite materials due to water in the free volumes of the polymer. These equations are applied to a specific polymer composite material during isothermal heating conditions. The thermal stresses obtained by the application of the theory are compared to measured results to verify the accuracy of the approach.

Improvement of acoustical characteristics : wideband bamboo based polymer composite

Science.gov (United States)

Farid, M.; Purniawan, A.; Rasyida, A.; Ramadhani, M.; Komariyah, S.

2017-07-01

Environmental friendly and comfortable materials are desirable for applications in the automobile interior. The objective of this research was to examine and develop bamboo based polymer composites applied to the sound absorption materials of automobile door panels. Morphological analysis of the polyurethane/bamboo powder composite materials was carried out using scanning electron microscope to reveal the microscopic material behavior and followed by the FTIR and TGA testing. The finding demonstrated that this acoustical polymer composite materials provided a potential wideband sound absorption material. The range of frequency can be controlled between 500 and 4000 Hz with an average of sound absorption coefficient around 0.411 and it met to the door panels criteria.

Smooth Nanowire/Polymer Composite Transparent Electrodes

KAUST Repository

Gaynor, Whitney; Burkhard, George F.; McGehee, Michael D.; Peumans, Peter

2011-01-01

Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Smooth Nanowire/Polymer Composite Transparent Electrodes

KAUST Repository

Gaynor, Whitney

2011-04-29

Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Role of the polymer phase in the mechanics of nacre-like composites

Science.gov (United States)

Niebel, Tobias P.; Bouville, Florian; Kokkinis, Dimitri; Studart, André R.

2016-11-01

Although strength and toughness are often mutually exclusive properties in man-made structural materials, nature is full of examples of composite materials that combine these properties in a remarkable way through sophisticated multiscale architectures. Understanding the contributions of the different constituents to the energy dissipating toughening mechanisms active in these natural materials is crucial for the development of strong artificial composites with a high resistance to fracture. Here, we systematically study the influence of the polymer properties on the mechanics of nacre-like composites containing an intermediate fraction of mineral phase (57 vol%). To this end, we infiltrate ceramic scaffolds prepared by magnetically assisted slip casting (MASC) with monomers that are subsequently cured to yield three drastically different polymers: (i) poly(lauryl methacrylate) (PLMA), a soft and weak elastomer; (ii) poly(methyl methacrylate) (PMMA), a strong, stiff and brittle thermoplastic; and (iii) polyether urethane diacrylate-co-poly(2-hydroxyethyl methacrylate) (PUA-PHEMA), a tough polymer of intermediate strength and stiffness. By combining our experimental data with finite element modeling, we find that stiffer polymers can increase the strength of the composite by reducing stress concentrations in the inorganic scaffold. Moreover, infiltrating the scaffolds with tough polymers leads to composites with high crack initiation toughness KIC. An organic phase with a minimum strength and toughness is also required to fully activate the mechanisms programmed within the ceramic structure for a rising R-curve behavior. Our results indicate that a high modulus of toughness is a key parameter for the selection of polymers leading to strong and tough bioinspired nacre-like composites.

Three-Dimensional (3D) Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling.

Science.gov (United States)

Fafenrot, Susanna; Grimmelsmann, Nils; Wortmann, Martin; Ehrmann, Andrea

2017-10-19

Fused deposition modeling (FDM) is a three-dimensional (3D) printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid) (PLA) printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength.

Large energy absorption in Ni-Mn-Ga/polymer composites

International Nuclear Information System (INIS)

Feuchtwanger, Jorge; Richard, Marc L.; Tang, Yun J.; Berkowitz, Ami E.; O'Handley, Robert C.; Allen, Samuel M.

2005-01-01

Ferromagnetic shape memory alloys can respond to a magnetic field or applied stress by the motion of twin boundaries and hence they show large hysteresis or energy loss. Ni-Mn-Ga particles made by spark erosion have been dispersed and oriented in a polymer matrix to form pseudo 3:1 composites which are studied under applied stress. Loss ratios have been determined from the stress-strain data. The loss ratios of the composites range from 63% to 67% compared to only about 17% for the pure, unfilled polymer samples

Assessment of nanoparticle release and associated health effect of polymer-silicon composites

International Nuclear Information System (INIS)

Zhu, H; Irfan, A; Sachse, S; Njuguna, J

2012-01-01

Little information is currently available on possible release of nanomaterials or/and nanoparticles (NP) from conventional and novel products and associated health effect. This study aimed to assess the possible release of NP during the application stage of conventional and nanoproducts. NP release was monitored during physical processing of polymer-silicon composites, and the toxicity of both the released NP and the raw silica nanomaterials that were used as fillers in the nanocomposites was assessed in vitro using human lung epithelial A549 cells. This study suggests that 1) NP can be released from the conventional and novel polymer-silicon composites under certain application scenario; 2) the level of NP release from polymer composites could be altered by different reinforcement materials; e.g. nanostructured MMT could reduce the release while SiO2 NP could increase the release; 3) working with polymer composites under certain conditions could risk inhalation of high level of polymer NP; 4) raw nanomaterials appeared to be toxic in the chosen in vitro system. Further study of the effect of novel filler materials on NP release from final polymer products and the effect of released NP on environment and human health will inform design of safe materials and minimization of negative impact on the environment and human health.

Transparent Nanoporous Glass-Polymer Composite for U.S. Army Applications

Science.gov (United States)

2008-10-01

material is created by infiltrating nanoporous glass (Vycor, Corning Inc.) with different polymers. The Vycor pores (4–6 nm) are much smaller than the...glass-polymer composite to a carbon-silica composite through pyrolysis . Sotomayor et al. (12) used polyanaline-infused Vycor to produce a pH sensor...Vycor is a registered trademark of Corning , Inc., Corning , NY. 3 In this report, we will explore the processing and mechanical behavior of

Electrospun Polymer Nanofibers Decorated with Noble Metal Nanoparticles for Chemical Sensing.

Science.gov (United States)

Chen, Chen; Tang, Yongan; Vlahovic, Branislav; Yan, Fei

2017-12-01

The integration of different noble metal nanostructures, which exhibit desirable plasmonic and/or electrocatalytic properties, with electrospun polymer nanofibers, which display unique mechanical and thermodynamic properties, yields novel hybrid nanoscale systems of synergistic properties and functions. This review summarizes recent advances on how to incorporate noble metal nanoparticles into electrospun polymer nanofibers and illustrates how such integration paves the way towards chemical sensing applications with improved sensitivity, stability, flexibility, compatibility, and selectivity. It is expected that further development of this field will eventually make a wide impact on many areas of research.

Characteristic of Polymer-Impregnated Cement Mortar: Composites: Bulk Density and Microstructure

International Nuclear Information System (INIS)

Younes, M.M.; Abo-El-Enein, S.A.; El-Saft, M.M.; Sadek, M.A.; Zohdy, K.M.

2010-01-01

The effect of radiation initiated polymerization of some monomers on the physical properties of polymer-incorporated mortar was studied. The monomers used were: castor oil (C.O.), 4, 4'-diphenylmethane diisocyanate (MDI) and methyl methacrylate (MMA). Polymerization was carried out by subjecting the monomer-impregnated mortar specimens to different doses of gamma radiation. Where polyurethane (pu) and polyurethane -methyl methacrylate copolymers were formed within the pore system. The influence of polymer impregnation on the various physico-mechanical characteristics of the resulting composites was studied with respect to bulk density and polymer loading. Scanning electron microscopy (SEM) was employed to study the micro-structural characteristics of the neat hardened Ordinary Portland Cement (OPC) mortar pastes and their polymer-impregnated composites

Ionic conductivity of polymer gels deriving from alkali metal ionic liquids and negatively charged polyelectrolytes

International Nuclear Information System (INIS)

Ogihara, Wataru; Sun Jiazeng; Forsyth, Maria; MacFarlane, Douglas R.; Yoshizawa, Masahiro; Ohno, Hiroyuki

2004-01-01

We have prepared polymer gel electrolytes with alkali metal ionic liquids (AMILs) that inherently contain alkali metal ions. The AMIL consisted of sulfate anion, imidazolium cation, and alkali metal cation. AMILs were mixed directly with poly(3-sulfopropyl acrylate) lithium salt or poly(2-acrylamido-2-methylpropanesulfonic acid) lithium salt to form polymer gels. The ionic conductivity of these gels decreased with increasing polymer fraction, as in general ionic liquid/polymer mixed systems. At low polymer concentrations, these gels displayed excellent ionic conductivity of 10 -4 to 10 -3 S cm -1 at room temperature. Gelation was found to cause little change in the 7 Li diffusion coefficient of the ionic liquid, as measured by pulse-field-gradient NMR. These data strongly suggest that the lithium cation migrates in successive pathways provided by the ionic liquids

The Stress and Stiffness Analysis of Diaphragm

Directory of Open Access Journals (Sweden)

Qu Dongyue

2017-01-01

Full Text Available Diaphragm coupling with its simple structure, small size, high reliability, which can compensate for its input and output displacement deviation by its elastic deformation, is widely used in aerospace, marine, and chemical etc. This paper uses the ANSYS software and its APDL language to analysis the stress distribution when the diaphragm under the load of torque, axial deviation, centrifugal force, angular deviation and multiple loads. We find that the value of maximum stress usually appears in the outer or inner transition region and the axial deviation has a greater influence to the distribution of the stress. Based on above, we got three kinds of stiffness for axial, angular and torque, which the stiffness of diaphragm is nearly invariable. The results can be regard as an important reference for design and optimization of diaphragm coupling.

Photocatalytic activity of PANI loaded coordination polymer composite materials: Photoresponse region extension and quantum yields enhancement via the loading of PANI nanofibers on surface of coordination polymer

International Nuclear Information System (INIS)

Cui, Zhongping; Qi, Ji; Xu, Xinxin; Liu, Lu; Wang, Yi

2013-01-01

To enhance photocatalytic property of coordination polymer in visible light region, polyaniline (PANI) loaded coordination polymer photocatalyst was synthesized through in-situ chemical oxidation of aniline on the surface of coordination polymer. The photocatalytic activity of PANI loaded coordination polymer composite material for degradation of Rhodamine B (RhB) was investigated. Compared with pure coordination polymer photocatalyst, which can decompose RhB merely under UV light irradiation, PANI loaded coordination polymer photocatalyst displays more excellent photocatalytic activity in visible light region. Furthermore, PANI loaded coordination polymer photocatalyst exhibits outstanding stability during the degradation of RhB. - Graphical abstract: PANI loaded coordination polymer composite material, which displays excellent photocatalytic activity under visible light was firstly synthesized through in-situ chemical oxidation of aniline on surface of coordination polymer. Display Omitted - Highlights: • This PANI loaded coordination polymer composite material represents the first conductive polymer loaded coordination polymer composite material. • PANI/coordination polymer composite material displays more excellent photocatalytic activity for the degradation of MO in visible light region. • The “combination” of coordination polymer and PANI will enable us to design high-activity, high-stability and visible light driven photocatalyst in the future

Removal and recovery of toxic metal ions from aqueous waste sites using polymer pendant ligands

International Nuclear Information System (INIS)

Fish, D.

1996-01-01

The purpose of this project is to investigate the use of polymer pendant ligand technology to remove and recover toxic metal ions from DOE aqueous waste sites. Polymer pendant lgiands are organic ligands, anchored to crosslinked, modified divinylbenzene-polystyrene beads, that can selectively complex metal ions. The metal ion removal step usually occurs through a complexation or ion exchange phenomena, thus recovery of the metal ions and reuse of the beads is readily accomplished

A novel approach in preparing polymer/nano-CaCO3 composites

Institute of Scientific and Technical Information of China (English)

Zhengying LIU; Runze YU; Mingbo YANG; Jianmin FENG; Wei YANG; Bo YIN

2008-01-01

An novel compounding process using nano-CaCO3 aqueous suspension for preparing polymer/ nano-CaCO3 composites with nanoparticles dispersed at the nanoscale is reported. The process is called the mild mixing method. In this method, the pre-dispersed nano-particle suspensions are blended with melting polymers in a weak shearing field using an extruder, followed by removing the water from the vent. The four typical poly-meric nanocomposites were prepared by mild mixing method. The dispersion of nano-CaCO3 in the matrix of the polymer at the nanoscale was confirmed by scanning electron microscopy (SEM). The molecular weights of polycarbonate (PC) and its nanocomposite showed that the degradation had not occurred during the mild mixing processing. The mechanical properties of the composite with 1.5 wt-% nano-CaCO3 improve slightly. It proved that this approach is suitable for the preparation of nano-composites based on both polar and non-polar polymers.

Solid polymer composite electrolytes for PEMFC

Energy Technology Data Exchange (ETDEWEB)

Zaidi, S M.J.; Mikhailenko, S D; Kaliaguine, S

1998-07-01

Composite electrolyte membranes for fuel cell technology were prepared from solid state proton conductors and polymer binders. The polymers were partially sulfonated and non-sulfonated polysulfone (PS), porous polyetherimide (PEI) and polymethylmethacrylate (PMMA). As proton conductors H-chabazite, tungstophosphoric acid and its Na-salt and non-stoichiometric boron phosphate were employed. All membranes prepared using sulfonated PS as a binder with sulfonation degree higher than 50% were found to be mechanically unstable. They possess however reasonably high conductivity up to 6{times}10{sup {minus}3} S/cm. Introducing the tungstophosphoric acid (TPA) into the nonsulfonated porous PS makes possible to obtain strong and flexible membranes with s=4{times}10{sup {minus}3} S/cm, while use of boron phosphate in that case results in the conductivity of about 10{sup {minus}5} S/cm. Porous PEI impregnated with aqueous solution of TPA retains its original tensile strength and exhibited the conductivity s=2{times}10{sup {minus}4} S/cm. It however fell to 3{times}10{sup {minus}5} S/cm when the binder was modified with 2% of propionic acid, which caused a decrease in polymer pore size. Incorporation of the sodium acid salt of TPA into PEI allows one to obtain a composite with reasonably good mechanical properties and a conductivity of ca 10{sup {minus}5} S/cm for membranes prepared by the cast method. Using the phase inversion technique for preparation of the membranes of the same composition makes possible to increase their conductivity up to 10{sup {minus}4} S/cm. When boron phosphate was used in lieu of TPA salt the conductivity obtained is still higher reaching 3{times}10{sup {minus}5} and 3{times}10{sup {minus}4} S/cm for membranes prepared by cast and phase inversion techniques respectively. The PMMA based membranes were mechanically stable even when a solid content reached 55wt.%. Among PMMA membranes the highest conductivity of 10{sup {minus}3} S/cm was registered for

The use of polymer gel dosimetry to measure dose distribution around metallic implants

International Nuclear Information System (INIS)

Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

2014-01-01

A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances. (author)

[The use of polymer gel dosimetry to measure dose distribution around metallic implants].

Science.gov (United States)

Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

2014-10-01

A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances.

Effects of surface roughening on the mass transport and mechanical properties of ionic polymer-metal composite

Science.gov (United States)

Chang, Longfei; Asaka, Kinji; Zhu, Zicai; Wang, Yanjie; Chen, Hualing; Li, Dichen

2014-06-01

Ionic Polymer-Metal Composite (IPMC) has been well-documented of being a promising functional material in extensive applications. In its most popular and traditional manufacturing technique, roughening is a key process to ensure a satisfying performance. In this paper, based on a lately established multi-physical model, the effect of roughening process on the inner mass transportation and the electro-active output of IPMC were investigated. In the model, the electro-chemical field was monitored by Poisson equation and a properly simplified Nernst-Planck equation set, while the mechanical field was evaluated on the basis of volume strain effect. Furthermore, with Ramo-Shockley theorem, the out-circuit current and accumulated charge on the electrode were bridged with the inner cation distribution. Besides, nominal current and charge density as well as the curvature of the deformation were evaluated to characterize the performance of IPMC. The simulation was implemented by Finite Element Method with Comsol Multi-physics, based on two groups of geometrical models, those with various rough interface and those with different thickness. The results of how the roughening impact influences on the performance of IPMC were discussed progressively in three aspects, steady-state distribution of local potential and mass concentration, current response and charge accumulation, as well as the curvature of deformation. Detailed explanations for the performance improvement resulted from surface roughening were provided from the micro-distribution point of view, which can be further explored for the process optimization of IPMC.

Bio-mineralisation on the composites of silicon-based polymer and nanodiamond particles by a species of Serratia Bacteria

International Nuclear Information System (INIS)

Sammon, R.; Mitev, D.; Pramatarova, L.; Hikov, T.; Radeva, E.; Presker, R.

2014-01-01

Serratia sp. NCIMB 40259 is a non-pathogenic Gram-negative bacterium that is able to produce hydroxyapatite by a mechanism involving enzymic cleavage of organic phosphates. Serratia bacteria can attach and form a biofilm on glass, plastics, ceramics and metals and the method can be used to form three dimensional porous scaffolds and for coating 3D structures with hydroxyapatite. The production of calcium phosphate is driven by an acid phosphatase enzyme located in the bacterial cell wall, on fimbriae and within the bacterial extracellular polymeric matrix. Calcium phosphate ceramic may be obtained by two methods: In the first, crystals of calcium phosphate are formed extracellularly within the pre-formed bacterial biofilm grown on the substrata. In the second method, planktonic bacteria catalyse the formation of CaP in suspension and on solid substrata placed in the same container. Composite thin layer of silicon-based polymer and detonated nanodiamond (DND) particles was used as substrate for the process of biomineralization by a species of Serratia. The plasma polymerization (PP) method was chosen to obtain composites of silicon-based polymer, in which DND particles were incorporated. Over the past decades carbon-based nanostructures have been the focus of intense research due to their unique chemical and physical properties. Recently it was shown that the incorporation of the DND particles in a polymer matrix (an organosilicon polymer) changes their physico-chemical properties. The composite films are homogeneous, chemically resistant, thermally and mechanically stable, thus allowing a large amount of biological components to be loaded onto their surface and to be used in tissue engineering, regenerative medicine, implants, stents, biosensors and other medical and biological devices. The aim of this study was to investigate the process of biomineralisation by Serratia bacteria on various composites of silicon-based polymer and detonated nanodiamond particles

Metal removal from aqueous media by polymer-assisted ultrafiltration with chitosan

Directory of Open Access Journals (Sweden)

Grégorio Crini

2017-05-01

Full Text Available Polymer assisted ultrafiltration (PAUF is a relatively new process in water and wastewater treatment and the subject of an increasing number of papers in the field of membrane science. Among the commercial polymers used, poly(ethyleneimine and poly(acrylic acid are the most popular to complex numerous metal ions. Recently, there is an increasing interest in the use of chitosan, a natural linear polymer, as chelating agent for complexing metals. Chitosan has a high potential in wastewater treatment mainly due to its polyelectrolyte properties at acidic pH. The objectives of this review are to present the PAUF process and to highlight the advantages gained from the use of chitosan in the process of complexation–ultrafiltration. For this, a PAUF-based literature survey has been compiled and is discussed. From these data, chitosan, a biopolymer that is non-toxic to humans and the environment, is found to be effective in removing metal ions and exhibits high selectivity. It might be a promising polyelectrolyte for PAUF purposes.

Metal hydride compositions and lithium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Young, Kwo; Nei, Jean

2018-04-24

Heterogeneous metal hydride (MH) compositions comprising a main region comprising a first metal hydride and a secondary region comprising one or more additional components selected from the group consisting of second metal hydrides, metals, metal alloys and further metal compounds are suitable as anode materials for lithium ion cells. The first metal hydride is for example MgH.sub.2. Methods for preparing the composition include coating, mechanical grinding, sintering, heat treatment and quenching techniques.

Polymer-Nanoparticle Composites: From Synthesis to Modern Applications

Directory of Open Access Journals (Sweden)

Thomas Hanemann

2010-05-01

Full Text Available The addition of inorganic spherical nanoparticles to polymers allows the modification of the polymers physical properties as well as the implementation of new features in the polymer matrix. This review article covers considerations on special features of inorganic nanoparticles, the most important synthesis methods for ceramic nanoparticles and nanocomposites, nanoparticle surface modification, and composite formation, including drawbacks. Classical nanocomposite properties, as thermomechanical, dielectric, conductive, magnetic, as well as optical properties, will be summarized. Finally, typical existing and potential applications will be shown with the focus on new and innovative applications, like in energy storage systems.

Electrochromic artificial muscles based on nanoporous metal-polymer composites

NARCIS (Netherlands)

Detsi, E.; Onck, P. R.; De Hosson, J. T. M.

2013-01-01

This work shows that a nano-coating of electrochromic polymer grown onto the ligaments of nanoporous gold causes reversible dimensional and color changes during electrochemical actuation. This combination of electromechanical and optical properties opens additional avenues for the applications of

Salt-Driven Deposition of Thermoresponsive Polymer-Coated Metal Nanoparticles on Solid Substrates.

Science.gov (United States)

Zhang, Zhiyue; Maji, Samarendra; da Fonseca Antunes, André B; De Rycke, Riet; Hoogenboom, Richard; De Geest, Bruno G

2016-06-13

Here we report on a simple, generally applicable method for depositing metal nanoparticles on a wide variety of solid surfaces under all aqueous conditions. Noble-metal nanoparticles obtained by citrate reduction followed by coating with thermoresponsive polymers spontaneously form a monolayer-like structure on a wide variety of substrates in presence of sodium chloride whereas this phenomenon does not occur in salt-free medium. Interestingly, this phenomenon occurs below the cloud point temperature of the polymers and we hypothesize that salt ion-induced screening of electrostatic charges on the nanoparticle surface entropically favors hydrophobic association between the polymer-coated nanoparticles and a hydrophobic substrate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studies on the optimization of deformation processed metal metal matrix composites

Energy Technology Data Exchange (ETDEWEB)

Ellis, Tim W. [Iowa State Univ., Ames, IA (United States)

1994-01-04

A methodology for the production of deformation processed metal metal matrix composites from hyper-eutectic copper-chromium alloys was developed. This methodology was derived from a basic study of the precipitation phenomena in these alloys encompassing evaluation of microstructural, electrical, and mechanical properties. The methodology developed produces material with a superior combination of electrical and mechanical properties compared to those presently available in commercial alloys. New and novel alloying procedures were investigated to extend the range of production methods available for these material. These studies focused on the use of High Pressure Gas Atomization and the development of new containment technologies for the liquid alloy. This allowed the production of alloys with a much more refined starting microstructure and lower contamination than available by other methods. The knowledge gained in the previous studies was used to develop two completely new families of deformation processed metal metal matrix composites. These composites are based on immissible alloys with yttrium and magnesium matrices and refractory metal reinforcement. This work extends the physical property range available in deformation processed metal metal matrix composites. Additionally, it also represents new ways to apply these metals in engineering applications.

Magnetic polymer-silica composites as bioluminescent sensors for bilirubin detection

Energy Technology Data Exchange (ETDEWEB)

Timin, Alexander S., E-mail: a_timin@mail.ru [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation); RASA Center in Tomsk, Tomsk Polytechnic University, pros. Lenina, 30, Tomsk (Russian Federation); Solomonov, Alexey V. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation); Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 7610001 (Israel); Kumagai, Akiko; Miyawaki, Atsushi [Cell Function Dynamics, Brain Science Institute RIKEN, 2-1 Hirosawa, Wako-city, Saitama, 351-0198 (Japan); Khashirova, Svetlana Yu; Zhansitov, Azamat [Kabardino-Balkar State University, 173 Chernyshevskogo St., Nal' chik, 360004, Kabardino-Balkaria (Russian Federation); Rumyantsev, Evgeniy V. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation)

2016-11-01

The synthesis of multifunctional nano-sized materials is leading to the rapid development of key application, including improved drug delivery, bioimaging and protein separation. In this work, magnetic silica particles modified with novel guanidine containing co-polymers were manufactured via sol-gel method. To evaluate the chemical composition of our prepared samples, FT-IR spectroscopy and thermogravimetry were conducted. Scanning electron microscopy was used in order to investigate the morphology of final products after modification by guanidine containing co-polymers and iron nanoparticles. In addition, the surface of polymer-silica composites was functionalized by the novel bilirubin-inducible fluorescent protein UnaG. In an aqueous bilirubin solution, the silica particles decorated with the polymer-UnaG have showed bright fluorescence. Synthesis and characterization of these hybrid materials allow developing of new multifunctional nano-sized materials, which will be used for detection and separation of bilirubin, a lipophilic heme catabolite that is a clinical diagnostic for liver function. - Highlights: • Novel magnetic silicas grafted by guanidine containing co-polymers were prepared. • Unag protein was effectively loaded into polymer coated silicas. • The fluorescent properties depend on content of bilirubin.

Magnetic polymer-silica composites as bioluminescent sensors for bilirubin detection

International Nuclear Information System (INIS)

Timin, Alexander S.; Solomonov, Alexey V.; Kumagai, Akiko; Miyawaki, Atsushi; Khashirova, Svetlana Yu; Zhansitov, Azamat; Rumyantsev, Evgeniy V.

2016-01-01

The synthesis of multifunctional nano-sized materials is leading to the rapid development of key application, including improved drug delivery, bioimaging and protein separation. In this work, magnetic silica particles modified with novel guanidine containing co-polymers were manufactured via sol-gel method. To evaluate the chemical composition of our prepared samples, FT-IR spectroscopy and thermogravimetry were conducted. Scanning electron microscopy was used in order to investigate the morphology of final products after modification by guanidine containing co-polymers and iron nanoparticles. In addition, the surface of polymer-silica composites was functionalized by the novel bilirubin-inducible fluorescent protein UnaG. In an aqueous bilirubin solution, the silica particles decorated with the polymer-UnaG have showed bright fluorescence. Synthesis and characterization of these hybrid materials allow developing of new multifunctional nano-sized materials, which will be used for detection and separation of bilirubin, a lipophilic heme catabolite that is a clinical diagnostic for liver function. - Highlights: • Novel magnetic silicas grafted by guanidine containing co-polymers were prepared. • Unag protein was effectively loaded into polymer coated silicas. • The fluorescent properties depend on content of bilirubin.

Influence of composition of functional additives and deformation modes on flow behavior of polymer composite materials

Science.gov (United States)

Onoprienko, N. N.; Rahimbaev, Sh M.

2018-03-01

The paper presents the results of the influence of composition of functional water-soluble polymers and viscosity of domestic and foreign one-percent water solution polymer on flow parameters of cement and polymer test. It also gives the results of rheogoniometry of Eunice Granit tile adhesive used for large-size plates from natural stone and ceramic granite.

Glass transition temperature of polymer nano-composites with polymer and filler interactions

Science.gov (United States)

Hagita, Katsumi; Takano, Hiroshi; Doi, Masao; Morita, Hiroshi

2012-02-01

We systematically studied versatile coarse-grained model (bead spring model) to describe filled polymer nano-composites for coarse-grained (Kremer-Grest model) molecular dynamics simulations. This model consists of long polymers, crosslink, and fillers. We used the hollow structure as the filler to describe rigid spherical fillers with small computing costs. Our filler model consists of surface particles of icosahedra fullerene structure C320 and a repulsive force from the center of the filler is applied to the surface particles in order to make a sphere and rigid. The filler's diameter is 12 times of beads of the polymers. As the first test of our model, we study temperature dependence of volumes of periodic boundary conditions under constant pressures through NPT constant Andersen algorithm. It is found that Glass transition temperature (Tg) decrease with increasing filler's volume fraction for the case of repulsive interaction between polymer and fillers and Tg weakly increase for attractive interaction.

Water-soluble metal-binding polymers with ultrafiltration: A technology for the removal, concentration, and recovery of metal ions from aqueous streams

International Nuclear Information System (INIS)

Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

1997-01-01

The use of water-soluble metal-binding polymers coupled with ultrafiltration (UF) is a technology under development to selectively concentrate and recover valuable or regulated metal-ions from dilute process or waste waters. The polymers have a sufficiently large molecular size that they can be separated and concentrated using commercially available UF technology. The polymers can then be reused by changing the solution conditions to release the metal-ions, which are recovered in a concentrated form for recycle or disposal. Pilot-scale demonstrations have been completed for a variety of waste streams containing low concentrations of metal ions including electroplating wastes (zinc and nickel) and nuclear waste streams (plutonium and americium). Many other potential commercial applications exist including remediation of contaminated solids. An overview of both the pilot-scale demonstrated applications and small scale testing of this technology are presented

Water-soluble metal-binding polymers with ultrafiltration: A technology for the removal, concentration, and recovery of metal ions from aqueous streams

Energy Technology Data Exchange (ETDEWEB)

Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

1997-12-31

The use of water-soluble metal-binding polymers coupled with ultrafiltration (UF) is a technology under development to selectively concentrate and recover valuable or regulated metal-ions from dilute process or waste waters. The polymers have a sufficiently large molecular size that they can be separated and concentrated using commercially available UF technology. The polymers can then be reused by changing the solution conditions to release the metal-ions, which are recovered in a concentrated form for recycle or disposal. Pilot-scale demonstrations have been completed for a variety of waste streams containing low concentrations of metal ions including electroplating wastes (zinc and nickel) and nuclear waste streams (plutonium and americium). Many other potential commercial applications exist including remediation of contaminated solids. An overview of both the pilot-scale demonstrated applications and small scale testing of this technology are presented.

Fluid structure interaction in piston diaphragm pumps

NARCIS (Netherlands)

van Rijswick, R.J.A.

2017-01-01

Piston diaphragm pumps are used world-wide to transport abrasive and/or aggressive slurries against high discharge pressures in the mining, mineral processing and power industries. Limitation of excessive deformation of the diaphragm is of utmost importance for eliminating fatigue failures of the

Synthesis, Characterization and Some Properties of Chelating Polymers for Metal Ion Sorption

International Nuclear Information System (INIS)

Mohamed, A.S.A.