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Sample records for hybrid organic-siloxane polymer

  1. 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

  2. Hybrid Silicon Nanocone–Polymer Solar Cells

    KAUST Repository

    Jeong, Sangmoo

    2012-06-13

    Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm 2, which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution. © 2012 American Chemical Society.

  3. Hybrid Photonic Integration on a Polymer Platform

    Directory of Open Access Journals (Sweden)

    Ziyang Zhang

    2015-09-01

    Full Text Available To fulfill the functionality demands from the fast developing optical networks, a hybrid integration approach allows for combining the advantages of various material platforms. We have established a polymer-based hybrid integration platform (polyboard, which provides flexible optical input/ouptut interfaces (I/Os that allow robust coupling of indium phosphide (InP-based active components, passive insertion of thin-film-based optical elements, and on-chip attachment of optical fibers. This work reviews the recent progress of our polyboard platform. On the fundamental level, multi-core waveguides and polymer/silicon nitride heterogeneous waveguides have been fabricated, broadening device design possibilities and enabling 3D photonic integration. Furthermore, 40-channel optical line terminals and compact, bi-directional optical network units have been developed as highly functional, low-cost devices for the wavelength division multiplexed passive optical network. On a larger scale, thermo-optic elements, thin-film elements and an InP gain chip have been integrated on the polyboard to realize a colorless, dual-polarization optical 90° hybrid as the frontend of a coherent receiver. For high-end applications, a wavelength tunable 100Gbaud transmitter module has been demonstrated, manifesting the joint contribution from the polyboard technology, high speed polymer electro-optic modulator, InP driver electronics and ceramic electronic interconnects.

  4. Hybrid Silicon Nanocone–Polymer Solar Cells

    KAUST Repository

    Jeong, Sangmoo; Garnett, Erik C.; Wang, Shuang; Yu, Zongfu; Fan, Shanhui; Brongersma, Mark L.; McGehee, Michael D.; Cui, Yi

    2012-01-01

    Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm 2, which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution. © 2012 American Chemical Society.

  5. Carbon Redox-Polymer-Gel Hybrid Supercapacitors

    Science.gov (United States)

    Vlad, A.; Singh, N.; Melinte, S.; Gohy, J.-F.; Ajayan, P.M.

    2016-01-01

    Energy storage devices that provide high specific power without compromising on specific energy are highly desirable for many electric-powered applications. Here, we demonstrate that polymer organic radical gel materials support fast bulk-redox charge storage, commensurate to surface double layer ion exchange at carbon electrodes. When integrated with a carbon-based electrical double layer capacitor, nearly ideal electrode properties such as high electrical and ionic conductivity, fast bulk redox and surface charge storage as well as excellent cycling stability are attained. Such hybrid carbon redox-polymer-gel electrodes support unprecedented discharge rate of 1,000C with 50% of the nominal capacity delivered in less than 2 seconds. Devices made with such electrodes hold the potential for battery-scale energy storage while attaining supercapacitor-like power performances. PMID:26917470

  6. Polymer and polymer-hybrid nanoparticles from synthesis to biomedical applications

    CERN Document Server

    Rangelov, Stanislav

    2013-01-01

    Polymeric and hybrid nanoparticles have received increased scientific interest in terms of basic research as well as commercial applications, promising a variety of uses for nanostructures in fields including bionanotechnology and medicine. Condensing the relevant research into a comprehensive reference, Polymer and Polymer-Hybrid Nanoparticles: From Synthesis to Biomedical Applications covers an array of topics from synthetic procedures and macromolecular design to possible biomedical applications of nanoparticles and materials based on original and unique polymers. The book presents a well-r

  7. Hybrid Polymer-Network Hydrogels with Tunable Mechanical Response

    Directory of Open Access Journals (Sweden)

    Sebastian Czarnecki

    2016-03-01

    Full Text Available Hybrid polymer-network gels built by both physical and covalent polymer crosslinking combine the advantages of both these crosslinking types: they exhibit high mechanical strength along with excellent fracture toughness and extensibility. If these materials are extensively deformed, their physical crosslinks can break such that strain energy is dissipated and irreversible fracturing is restricted to high strain only. This mechanism of energy dissipation is determined by the kinetics and thermodynamics of the physical crosslinking contribution. In this paper, we present a poly(ethylene glycol (PEG based material toolkit to control these contributions in a rational and custom fashion. We form well-defined covalent polymer-network gels with regularly distributed additional supramolecular mechanical fuse links, whose strength of connectivity can be tuned without affecting the primary polymer-network composition. This is possible because the supramolecular fuse links are based on terpyridine–metal complexation, such that the mere choice of the fuse-linking metal ion adjusts their kinetics and thermodynamics of complexation–decomplexation, which directly affects the mechanical properties of the hybrid gels. We use oscillatory shear rheology to demonstrate this rational control and enhancement of the mechanical properties of the hybrid gels. In addition, static light scattering reveals their highly regular and well-defined polymer-network structures. As a result of both, the present approach provides an easy and reliable concept for preparing hybrid polymer-network gels with rationally designed properties.

  8. 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.

  9. Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    S. N. F. Mohd-Nasir

    2014-01-01

    Full Text Available The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells.

  10. 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%.

  11. Enzymatic synthesis of lignin-siloxane hybrid functional polymers.

    Science.gov (United States)

    Prasetyo, Endry Nugroho; Kudanga, Tukayi; Fischer, Roman; Eichinger, Reinhard; Nyanhongo, Gibson S; Guebitz, Georg M

    2012-02-01

    This study combines the properties of siloxanes and lignin polymers to produce hybrid functional polymers that can be used as adhesives, coating materials, and/or multifunctionalized thin-coating films. Lignin-silica hybrid copolymers were synthesized by using a sol-gel process. Laccases from Trametes hirsuta were used to oxidize lignosulphonates to enhance their reactivity towards siloxanes and then were incorporated into siloxane precursors undergoing a sol-gel process. In vitro copolymerization studies using pure lignin monomers with aminosilanes or ethoxytrimethylsilane and analysis by ²⁹Si NMR spectroscopy revealed hybrid products. Except for kraft lignin, an increase in lignin concentration positively affected the tensile strength in all samples. Similarly, the viscosity generally increased in all samples with increasing lignin concentration and also affected the curing time. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Hybrid protein-synthetic polymer nanoparticles for drug delivery.

    Science.gov (United States)

    Koseva, Neli S; Rydz, Joanna; Stoyanova, Ekaterina V; Mitova, Violeta A

    2015-01-01

    Among the most common nanoparticulate systems, the polymeric nanocarriers have a number of key benefits, which give a great choice of delivery platforms. Nevertheless, polymeric nanoparticles possess some limitations that include use of toxic solvents in the production process, polymer degradation, drug leakage outside the diseased tissue, and polymer cytotoxicity. The combination of polymers of biological and synthetic origin is an appealing modern strategy for the production of novel nanocarriers with unprecedented properties. Proteins' interface can play an important role in determining bioactivity and toxicity and gives perspective for future development of the polymer-based nanoparticles. The design of hybrid constructs composed of synthetic polymer and biological molecules such as proteins can be considered as a straightforward tool to integrate a broad spectrum of properties and biofunctions into a single device. This review discusses hybrid protein-synthetic polymer nanoparticles with different structures and levels in complexity and functionality, in view of their applications as drug delivery systems. © 2015 Elsevier Inc. All rights reserved.

  13. Polymer degradation rate control of hybrid rocket combustion

    Science.gov (United States)

    Stickler, D. B.; Ramohalli, K. N. R.

    1970-01-01

    Polymer degradation to small fragments is treated as a rate controlling step in hybrid rocket combustion. Both numerical and approximate analytical solutions of the complete energy and polymer chain bond conservation equations for the condensed phase are obtained. Comparison with inert atmosphere data is very good. It is found that the intersect of curves of pyrolysis rate versus interface temperature for hybrid combustors, with the thermal degradation theory, falls at a pyrolysis rate very close to that for which a pressure dependence begins to be observable. Since simple thermal degradation cannot give sufficient depolymerization at higher pyrolysis rates, it is suggested that oxidative catalysis of the process occurs at the surface, giving a first order dependence on reactive species concentration at the wall. Estimates of the ratio of this activation energy and interface temperature are in agreement with best fit procedures for hybrid combustion data. Requisite active species concentrations and flux are shown to be compatible with turbulent transport. Pressure dependence of hybrid rocket fuel regression rate is thus shown to be describable in a consistent manner in terms of reactive species catalysis of polymer degradation.

  14. Thermal Properties of Hybrid Carbon Nanotube/Carbon Fiber Polymer

    Science.gov (United States)

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

    2016-01-01

    Carbon fiber reinforced polymer (CFRP) composites possess many advantages for aircraft structures over conventional aluminum alloys: light weight, higher strength- and stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low thermal and electrical conductivities of CFRP composites are deficient in providing structural safety under certain operational conditions such as lightning strikes. One possible solution to these issues is to interleave carbon nanotube (CNT) sheets between conventional carbon fiber (CF) composite layers. However, the thermal and electrical properties of the orthotropic hybrid CNT/CF composites have not been fully understood. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel (Registered Trademark) IM7/8852 prepreg. The CNT sheets were infused with a 5% solution of a compatible epoxy resin prior to composite fabrication. Orthotropic thermal and electrical conductivities of the hybrid polymer composites were evaluated. The interleaved CNT sheets improved the in-plane thermal conductivity of the hybrid composite laminates by about 400% and the electrical conductivity by about 3 orders of magnitude.

  15. Functionalised hybrid materials of conducting polymers with individual wool fibers.

    Science.gov (United States)

    Kelly, Fern M; Johnston, James H; Borrmann, Thomas; Richardson, Michael J

    2008-04-01

    Composites of natural protein materials, such as merino wool, with the conducting polymers polypyrrole (PPy) and polyaniline (PAn) have been successfully synthesised. In doing so, hybrid materials have been produced in which the mechanical strength and flexibility of the fibers is retained whilst also incorporating the desired chemical and electrical properties of the polymer. Scanning electron microscopy shows PPy coatings to comprise individual polymer spheres, approximately 100 to 150 nm in diameter. The average size of the polymer spheres of PAn was observed to be approximately 50 to 100 nm in diameter. These spheres fuse together in a continuous sheet to coat the fibers in their entirety. The reduction of silver ions to silver metal nanoparticles onto the redox active polymer surface has also been successful and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterisation of such products has been undertaken through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electrical conductivity, cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and the testing of their anti-microbial activity.

  16. Hybrid polymer photonic crystal fiber with integrated chalcogenide glass nanofilms

    DEFF Research Database (Denmark)

    Markos, Christos; Kubat, Irnis; Bang, Ole

    2014-01-01

    The combination of chalcogenide glasses with polymer photonic crystal fibers (PCFs) is a difficult and challenging task due to their different thermo-mechanical material properties. Here we report the first experimental realization of a hybrid polymer-chalcogenide PCF with integrated As2S3 glass...... nanofilms at the inner surface of the air-channels of a poly-methyl-methacrylate (PMMA) PCF. The integrated high refractive index glass films introduce distinct antiresonant transmission bands in the 480-900 nm wavelength region. We demonstrate that the ultra-high Kerr nonlinearity of the chalcogenide glass...

  17. Nanostructured hybrid materials from aqueous polymer dispersions.

    Science.gov (United States)

    Castelvetro, Valter; De Vita, Cinzia

    2004-05-20

    Organic-inorganic (O-I) hybrids with well-defined morphology and structure controlled at the nanometric scale represent a very interesting class of materials both for their use as biomimetic composites and because of their potential use in a wide range of technologically advanced as well as more conventional application fields. Their unique features can be exploited or their role envisaged as components of electronic and optoelectronic devices, in controlled release and bioencapsulation, as active substrates for chromatographic separation and catalysis, as nanofillers for composite films in packaging and coating, in nanowriting and nanolithography, etc. A synergistic combination or totally new properties with respect to the two components of the hybrid can arise from nanostructuration, achieved by surface modification of nanostructures, self-assembling or simply heterophase dispersion. In fact, owing to the extremely large total surface area associated with the resulting morphologies, the interfacial interactions can deeply modify the bulk properties of each component. A wide range of starting materials and of production processes have been studied in recent years for the controlled synthesis and characterization of hybrid nanostructures, from nanoparticle or lamellar dispersions to mesoporous materials obtained from templating nanoparticle dispersions in a continuous, e.g. ceramic precursor, matrix. This review is aimed at giving some basic definitions of what is intended as a hybrid (O-I) material and what are the main synthetic routes available. The various methods for preparing hybrid nanostructures and, among them, inorganic-organic or O-I core-shell nanoparticles, are critically analyzed and classified based on the reaction medium (aqueous, non-aqueous), and on the role it plays in directing the final morphology. Particular attention is devoted to aqueous systems and water-borne dispersions which, in addition to being environmentally more acceptable or even a

  18. Hybrid energy harvesting systems, using piezoelectric elements and dielectric polymers

    Science.gov (United States)

    Cornogolub, Alexandru; Cottinet, Pierre-Jean; Petit, Lionel

    2016-09-01

    Interest in energy harvesting applications has increased a lot during recent years. This is especially true for systems using electroactive materials like dielectric polymers or piezoelectric materials. Unfortunately, these materials despite multiple advantages, present some important drawbacks. For example, many dielectric polymers demonstrated high energy densities; they are cheap, easy to process and can be easily integrated in many different structures. But at the same time, dielectric polymer generators require an external energy supply which could greatly compromise their autonomy. Piezoelectric systems, on the other hand, are completely autonomous and can be easily miniaturized. However, most common piezoelectric materials present a high rigidity and are brittle by nature and therefore their integration could be difficult. This paper investigates the possibility of using hybrid systems combining piezoelectric elements and dielectric polymers for mechanical energy harvesting applications and it is focused mainly on the problem of electrical energy transfer. Our objective is to show that such systems can be interesting and that it is possible to benefit from the advantages of both materials. For this, different configurations were considered and the problem of their optimization was addressed. The experimental work enabled us to prove the concept and identify the main practical limitations.

  19. Impact Energy Absorbing Capability of Metal/Polymer Hybrid Sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Kyungil; Kwon, O Bum; Park, Hyung Wook [Ulsan Nat’l Institute of Science and Technology, Ulsan (Korea, Republic of)

    2017-02-15

    Recently, the reduction of vehicle weight has been increasingly studied, in order to enhance the fuel efficiency of passenger cars. In particular, the seat frame is being studied actively, owing to considerations of driver safety from external impact damage. Therefore, this study focuses on high strength steel sheet (SPFC980)/polymer heterojunction hybrid materials, and their performance in regards to impact energy absorption. The ratio of impact energy absorption was observed to be relatively higher in the SPFC980/polymer hybrid materials under the impact load. This was found by calculating the equivalent flexural rigidity, which is the bending effect, according to the Castigliano theorem. An efficient wire-web structure was investigated through the simulation of different wire-web designs such as triangular, rectangular, octagonal, and hexagonal structures. The hexagonal wire-web structure was shown to have the least impact damage, according to the simulations. This study can be utilized for seat frame design for passengers’ safety, owing to efficient impact absorption.

  20. Hybrid solar cells composed of perovskite and polymer photovoltaic structures

    Science.gov (United States)

    Phaometvarithorn, Apatsanan; Chuangchote, Surawut; Kumnorkaew, Pisist; Wootthikanokkhan, Jatuphorn

    2018-06-01

    Organic/inorganic lead halide perovskite solar cells have recently attracted much attention in photovoltaic research, due to the devices show promising ways to achieve high efficiencies. The perovskite devices with high efficiencies, however, are typically fabricated in tandem solar cell which is complicated. In this research work, we introduce a solar cell device with the combination of CH3NH3PbI3-xClx perovskite and bulk heterojunction PCDTBT:PC70BM polymer without any tandem structure. The new integrated perovskite/polymer hybrid structure of ITO/PEDOT:PSS/perovskite/PCDTBT:PC70BM/PC70BM/TiOx/Al provides higher power conversion efficiency (PCE) of devices compared with conventional perovskite cell structure. With the optimized PCDTBT:PC70BM thickness of ∼70 nm, the highest PCE of 11.67% is achieved. Variation of conducting donor polymers in this new structure is also preliminary demonstrated. This study provides an attractively innovative structure and a promising design for further development of the new-generation solar cells.

  1. Photoresponsive lipid-polymer hybrid nanoparticles for controlled doxorubicin release

    Science.gov (United States)

    Yao, Cuiping; Wu, Ming; Zhang, Cecheng; Lin, Xinyi; Wei, Zuwu; Zheng, Youshi; Zhang, Da; Zhang, Zhenxi; Liu, Xiaolong

    2017-06-01

    Currently, photoresponsive nanomaterials are particularly attractive due to their spatial and temporal controlled drug release abilities. In this work, we report a photoresponsive lipid-polymer hybrid nanoparticle for remote controlled delivery of anticancer drugs. This hybrid nanoparticle comprises three distinct functional components: (i) a poly(D,L-lactide-co-glycolide) (PLGA) core to encapsulate doxorubicin; (ii) a soybean lecithin monolayer at the interface of the core and shell to act as a molecular fence to prevent drug leakage; (iii) a photoresponsive polymeric shell with anti-biofouling properties to enhance nanoparticle stability, which could be detached from the nanoparticle to trigger the drug release via a decrease in the nanoparticle’s stability under light irradiation. In vitro results revealed that this core-shell nanoparticle had excellent light-controlled drug release behavior (76% release with light irradiation versus 10% release without light irradiation). The confocal microscopy and flow cytometry results also further demonstrated the light-controlled drug release behavior inside the cancer cells. Furthermore, a CCK8 assay demonstrated that light irradiation could significantly improve the efficiency of killing cancer cells. Meanwhile, whole-animal fluorescence imaging of a tumor-bearing mouse also confirmed that light irradiation could trigger drug release in vivo. Taken together, our data suggested that a hybrid nanoparticle could be a novel light controlled drug delivery system for cancer therapy.

  2. Electrochemical DNA Hybridization Sensors Based on Conducting Polymers

    Science.gov (United States)

    Rahman, Md. Mahbubur; Li, Xiao-Bo; Lopa, Nasrin Siraj; Ahn, Sang Jung; Lee, Jae-Joon

    2015-01-01

    Conducting polymers (CPs) are a group of polymeric materials that have attracted considerable attention because of their unique electronic, chemical, and biochemical properties. This is reflected in their use in a wide range of potential applications, including light-emitting diodes, anti-static coating, electrochromic materials, solar cells, chemical sensors, biosensors, and drug-release systems. Electrochemical DNA sensors based on CPs can be used in numerous areas related to human health. This review summarizes the recent progress made in the development and use of CP-based electrochemical DNA hybridization sensors. We discuss the distinct properties of CPs with respect to their use in the immobilization of probe DNA on electrode surfaces, and we describe the immobilization techniques used for developing DNA hybridization sensors together with the various transduction methods employed. In the concluding part of this review, we present some of the challenges faced in the use of CP-based DNA hybridization sensors, as well as a future perspective. PMID:25664436

  3. Electrochemical DNA Hybridization Sensors Based on Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Md. Mahbubur Rahman

    2015-02-01

    Full Text Available Conducting polymers (CPs are a group of polymeric materials that have attracted considerable attention because of their unique electronic, chemical, and biochemical properties. This is reflected in their use in a wide range of potential applications, including light-emitting diodes, anti-static coating, electrochromic materials, solar cells, chemical sensors, biosensors, and drug-release systems. Electrochemical DNA sensors based on CPs can be used in numerous areas related to human health. This review summarizes the recent progress made in the development and use of CP-based electrochemical DNA hybridization sensors. We discuss the distinct properties of CPs with respect to their use in the immobilization of probe DNA on electrode surfaces, and we describe the immobilization techniques used for developing DNA hybridization sensors together with the various transduction methods employed. In the concluding part of this review, we present some of the challenges faced in the use of CP-based DNA hybridization sensors, as well as a future perspective.

  4. Silicon nanowires in polymer nanocomposites for photovoltaic hybrid thin films

    International Nuclear Information System (INIS)

    Ben Dkhil, S.; Bourguiga, R.; Davenas, J.; Cornu, D.

    2012-01-01

    Highlights: ► Hybrid solar cells based on blends of poly(N-vinylcarbazole) and silicon nanowires have been fabricated. ► We have investigated the charge transfer between PVK and SiNWs by the way of the quenching of the PVK photoluminescence. ► The relation between the morphology of the composite thin films and the charge transfer between SiNWs and PVK has been examined. ► We have investigated the effects of SiNWs concentration on the photovoltaic characteristics leading to the optimization of a critical SiNWs concentration. - Abstract: Hybrid thin films combining the high optical absorption of a semiconducting polymer film and the electronic properties of silicon fillers have been investigated in the perspective of the development of low cost solar cells. Bulk heterojunction photovoltaic materials based on blends of a semiconductor polymer poly(N-vinylcarbazole) (PVK) as electron donor and silicon nanowires (SiNWs) as electron acceptor have been studied. Composite PVK/SiNWs films were cast from a common solvent mixture. UV–visible spectrometry and photoluminescence of the composites have been studied as a function of the SiNWs concentration. Photoluminescence spectroscopy (PL) shows the existence of a critical SiNWs concentration of about 10 wt % for PL quenching corresponding to the most efficient charge pair separation. The photovoltaic (PV) effect has been studied under illumination. The optimum open-circuit voltage V oc and short-circuit current density J sc are obtained for 10 wt % SiNWs whereas a degradation of these parameters is observed at higher SiNWs concentrations. These results are correlated to the formation of aggregates in the composite leading to recombination of the photogenerated charge pairs competing with the dissociation mechanism.

  5. Synthesis of hybrid polymers of beta-Cd and siloxanes

    International Nuclear Information System (INIS)

    Abbehausen, Camilla; Yoshida, Inez V.P.

    2009-01-01

    Hybrid polymers derived from siloxane and β-cyclodextrin (β-CD) were obtained from gamma-isocyanate-propyl-triethoxy-silane (IPTS) and β-CD. The resulting alkoxysilane was hydrolyzed generating glassy β-CD modified polysilsesquioxane. The alkoxysilane was also submitted to condensation with poly(dimethylsiloxane) with - Si(CH 3 -) 2 -OH end groups, giving rise to a polymeric network with β-CD at crosslinking nodes. These materials were characterized by infrared spectrum, 13 C and 29 Si nuclear magnetic resonance and X ray diffraction. The thermal behavior was analyzed by thermogravimetry. The capability of β-CD grafted in the siloxane polymers to form inclusion complexes was evaluated by the formation of β-CD-phenolphthalein complex, by UV-vis spectrum. The ability of water diffusion into β-CD-PSS film was evaluated by swollen measurement. β-CD-modified siloxanes were able to form films and their morphologies were evaluated by scanning electron microscopy. (author)

  6. Polymer-lipid hybrid nanoparticles as enhanced indomethacin delivery systems.

    Science.gov (United States)

    Dalmoro, Annalisa; Bochicchio, Sabrina; Nasibullin, Shamil F; Bertoncin, Paolo; Lamberti, Gaetano; Barba, Anna Angela; Moustafine, Rouslan I

    2018-05-17

    Non-steroidal anti-inflammatory drugs (NSAIDs), i.e. indomethacin used for rheumatoid arthritis and non-rheumatoid inflammatory diseases, are known for their injurious actions on the gastrointestinal (GI) tract. Mucosal damage can be avoided by using nanoscale systems composed by a combination of liposomes and biodegradable natural polymer, i.e. chitosan, for enhancing drug activity. Aim of this study was to prepare chitosan-lipid hybrid delivery systems for indomethacin dosage through a novel continuous method based on microfluidic principles. The drop-wise conventional method was also applied in order to investigate the effect of the two polymeric coverage processes on the nanostructures features and their interactions with indomethacin. Thermal-physical properties, mucoadhesiveness, drug entrapment efficiency, in vitro release behavior in simulated GI fluids and stability in stocking conditions were assayed and compared, respectively, for the uncoated and chitosan-coated nanoliposomes prepared by the two introduced methods. The prepared chitosan-lipid hybrid structures, with nanometric size, have shown high indomethacin loading (about 10%) and drug encapsulation efficiency up to 99%. TEM investigation has highlighted that the developed novel simil-microfluidic method is able to put a polymeric layer, surrounding indomethacin loaded nanoliposomes, thicker and smoother than that achievable by the drop-wise method, improving their storage stability. Finally, double pH tests have confirmed that the chitosan-lipid hybrid nanostructures have a gastro retentive behavior in simulated gastric and intestinal fluids thus can be used as delivery systems for the oral-controlled release of indomethacin. Based on the present results, the simil-microfluidic method, working with large volumes, in a rapid manner, without the use of drastic conditions and with a precise control over the covering process, seems to be the most promising method for the production of suitable

  7. Active metal oxides and polymer hybrids as biomaterials

    Science.gov (United States)

    Jarrell, John D.

    show that silver doping improved the photoactivity of oxide coatings, but hindered activity of a specific hybrid. Doped titanium oxide and polymer hybrid coatings have potential for improving soft tissue integration of medical implants and wound healing by modulating cell proliferation, attachment, inflammation and providing controlled delivery of bioactive and antimicrobial compounds and photon induced electro-chemical activity.

  8. Biocompatible Polymer/Quantum Dots Hybrid Materials: Current Status and Future Developments

    Directory of Open Access Journals (Sweden)

    Lei Shen

    2011-12-01

    Full Text Available Quantum dots (QDs are nanometer-sized semiconductor particles with tunable fluorescent optical property that can be adjusted by their chemical composition, size, or shape. In the past 10 years, they have been demonstrated as a powerful fluorescence tool for biological and biomedical applications, such as diagnostics, biosensing and biolabeling. QDs with high fluorescence quantum yield and optical stability are usually synthesized in organic solvents. In aqueous solution, however, their metallic toxicity, non-dissolubility and photo-luminescence instability prevent the direct utility of QDs in biological media. Polymers are widely used to cover and coat QDs for fabricating biocompatible QDs. Such hybrid materials can provide solubility and robust colloidal and optical stability in water. At the same time, polymers can carry ionic or reactive functional groups for incorporation into the end-use application of QDs, such as receptor targeting and cell attachment. This review provides an overview of the recent development of methods for generating biocompatible polymer/QDs hybrid materials with desirable properties. Polymers with different architectures, such as homo- and co-polymer, hyperbranched polymer, and polymeric nanogel, have been used to anchor and protect QDs. The resulted biocompatible polymer/QDs hybrid materials show successful applications in the fields of bioimaging and biosensing. While considerable progress has been made in the design of biocompatible polymer/QDs materials, the research challenges and future developments in this area should affect the technologies of biomaterials and biosensors and result in even better biocompatible polymer/QDs hybrid materials.

  9. Hybrid polymer composite membrane for an electromagnetic (EM) valveless micropump

    Science.gov (United States)

    Said, Muzalifah Mohd; Yunas, Jumril; Bais, Badariah; Azlan Hamzah, Azrul; Yeop Majlis, Burhanuddin

    2017-07-01

    In this paper, we report on a hybrid membrane used as an actuator in an electromagnetically driven valveless micropump developed using MEMS processes. The membrane structure consists of the combination of a magnetic polymer composite membrane and an attached bulk permanent magnet which is expected to have a compact structure and a strong magnetic force with maintained membrane flexibility. A soft polymeric material made of polydimethylsiloxane (PDMS) is initially mixed with neodymium magnetic particles (NdFeB) to form a magnetic polymer composite membrane. The membrane is then bonded with the PDMS based microfluidic part, developed using soft lithography process. The developed micropump was tested in terms of the actuator membrane deflection capability and the fluidic flow of the injected fluid sample through the microfluidic channel. The experimental results show that the magnetic composite actuator membrane with an attached bulk permanent magnet is capable of producing a maximum membrane deflection of up to 106 µm. The functionality test of the electromagnetic (EM) actuator for fluid pumping purposes was done by supplying an AC voltage with various amplitudes, signal waves and frequencies. A wide range of sample injection rates from a few µl min-1 to tens of nl min-1 was achieved with a maximum flow rate of 6.6 µl min-1. The injection flow rate of the EM micropump can be controlled by adjusting the voltage amplitude and frequency supplied to the EM coil, to control the membrane deflection in the pump chamber. The designed valveless EM micropump has a very high potential to enhance the drug delivery system capability in biomedical applications.

  10. 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

  11. Perspective: Hybrid solar cells: How to get the polymer to cooperate?

    Directory of Open Access Journals (Sweden)

    Jonas Weickert

    2013-08-01

    Full Text Available Lately, a lot of attention has been paid to metal oxide-organic hybrid solar cells. In these devices, conjugated polymers replace the typically transparent hole transporter as usually used in solid-state dye-sensitized solar cells in order to maximize the photon absorption efficiency. However, to unleash the full potential of hybrid solar cells it is imperative to push the photocurrent contribution of the absorbing polymer.

  12. Hybrid ZnO:polymer bulk heterojunction solar cells from a ZnO precursor

    NARCIS (Netherlands)

    Beek, W.J.E.; Slooff, L.H.; Wienk, M.M.; Kroon, J.M.; Janssen, R.A.J.; Kafafi, Z.H.

    2005-01-01

    We describe a simple and new method to create hybrid bulk heterojunction solar cells consisting of ZnO and conjugated polymers. A gel-forming ZnO precursor, blended with conjugated polymers, is converted into crystalline ZnO at temperatures as low as 110 °C. In-situ formation of ZnO in MDMO-PPV

  13. THz waveguides, devices and hybrid polymer-chalcogenide photonic crystal fibers

    DEFF Research Database (Denmark)

    Bao, Hualong; Markos, Christos; Nielsen, Kristian

    2014-01-01

    In this contribution, we review our recent activities in the design, fabrication and characterization of polymer THz waveguides. Besides the THz waveguides, we finally will also briefly show some of our initial results on a novel hybrid polymer photonic crystal fiber with integrated chalcogenide...

  14. Hybrid TiO2: polymer photovoltaic cells made from a titanium oxide precursor

    NARCIS (Netherlands)

    Slooff, L.H.; Wienk, M.M.; Kroon, J.M.

    2004-01-01

    Hybrid TiO2:polymer photovoltaic cells were made from mixtures of titanium(IV) isopropoxide and poly[2-methoxy-5-(3',7'-dimethyloctyl)-p-phenylene vinylene] (MDMO-PPV) or poly(3-octyl thiophene) (P3OT) via hydrolysis in air. Cells were made with varying titanium(IV) isopropoxide:polymer ratios.

  15. Porous-Hybrid Polymers as Platforms for Heterogeneous Photochemical Catalysis

    KAUST Repository

    Haikal, Rana R.

    2016-07-18

    A number of permanently porous polymers containing Ru(bpy)n photosensitizer or a cobaloxime complex, as a proton-reduction catalyst, were constructed via one-pot Sonogashira-Hagihara (SH) cross-coupling reactions. This process required minimal workup to access porous platforms with control over the apparent surface area, pore volume, and chemical functionality from suitable molecular building blocks (MBBs) containing the Ru or Co complexes, as rigid and multi-topic nodes. The cobaloxime molecular building block, generated through in situ metalation, afforded a microporous solid that demonstrated noticeable catalytic activity towards hydrogen-evolution reaction (HER) with remarkable recyclability. We further demonstrated, in two cases, the ability to affect the excited state lifetime of the covalently-immobilized Ru(bpy)3 complex attained through deliberate utilization of the organic linkers of variable dimensions. Overall, this approach facilitates construction of tunable porous solids, with hybrid composition and pronounced chemical and physical stability, based on the well-known Ru(bpy)nor the cobaloxime complexes.

  16. Porous-Hybrid Polymers as Platforms for Heterogeneous Photochemical Catalysis

    KAUST Repository

    Haikal, Rana R.; Wang, Xia; Hassan, Youssef S.; Parida, Manas R.; Banavoth, Murali; Mohammed, Omar F.; Pellechia, Perry J.; Fontecave, Marc; Alkordi, Mohamed H.

    2016-01-01

    A number of permanently porous polymers containing Ru(bpy)n photosensitizer or a cobaloxime complex, as a proton-reduction catalyst, were constructed via one-pot Sonogashira-Hagihara (SH) cross-coupling reactions. This process required minimal workup to access porous platforms with control over the apparent surface area, pore volume, and chemical functionality from suitable molecular building blocks (MBBs) containing the Ru or Co complexes, as rigid and multi-topic nodes. The cobaloxime molecular building block, generated through in situ metalation, afforded a microporous solid that demonstrated noticeable catalytic activity towards hydrogen-evolution reaction (HER) with remarkable recyclability. We further demonstrated, in two cases, the ability to affect the excited state lifetime of the covalently-immobilized Ru(bpy)3 complex attained through deliberate utilization of the organic linkers of variable dimensions. Overall, this approach facilitates construction of tunable porous solids, with hybrid composition and pronounced chemical and physical stability, based on the well-known Ru(bpy)nor the cobaloxime complexes.

  17. Synthèse d'hybrides polymère-polymère par la polymérisation en miniémulsion et la caractérisation des latex hybrides

    OpenAIRE

    Udagama , Ravindra

    2009-01-01

    The objectives of work presented in this thesis are to understand droplet and particle formulation processes in order to make useful polymer-polymer hybrids in aqueous dispersions and use our fundamental understanding of these processes to: 1. Improve monomer conversion as much as possible. 2. Understand impact of these processes on hybrid film properties. Specific case studies of interest under commercially feasible conditions (i.e. solids content of 50wt %) were done based on two systems na...

  18. Exploration of a Doxorubicin-Polymer Conjugate in Lipid-Polymer Hybrid Nanoparticle Drug Delivery

    Science.gov (United States)

    Lough, Emily

    Nanoparticle (NP) drug delivery is a major focus in the research community because of its potential to use existing drugs in safer and more effective ways. Chemotherapy encapsulation in NPs shields the drug from the rest of the body while it is within the NP, with less systemic exposure leading to fewer off-target effects of the drug. However, passive loading of drugs into NPs is a suboptimal method, often leading to burst release upon administration. This work explores the impact of incorporating the drug-polymer conjugate doxorubicin-poly (lactic-co-glycolic) acid (Dox-PLGA) into a lipid-polymer hybrid nanoparticle (LPN). The primary difference in using a drug-polymer conjugate for NP drug delivery is the drug's release kinetics. Dox-PLGA LPNs showed a more sustained and prolonged release profile over 28 days compared to LPNs with passively loaded, unconjugated doxorubicin. This sustained release translates to cytotoxicity; when systemic circulation was simulated using dialysis, Dox-PLGA LPNs retained their cytotoxicity at a higher level than the passively loaded LPNs. The in vivo implication of preserving cytotoxic potency through a slower release profile is that the majority of Dox delivered via Dox-PLGA LPNs will be kept within the LPN until it reaches the tumor. This will result in fewer systemic side effects and more effective treatments given the higher drug concentration at the tumor site. An intriguing clinical application of this drug delivery approach lies in using Dox-PLGA LPNs to cross the blood-brain barrier (BBB). The incorporation of Dox-PLGA is hypothesized to have a protective effect on the BBB as its slow release profile will prevent drug from harming the BBB. Using induced pluripotent stem cells differentiated to human brain microvascular endothelial cells that comprise the BBB, the Dox-PLGA LPNs were shown to be less destructive to the BBB than their passively loaded counterparts. Dox-PLGA LPNs showed superior cytotoxicity against plated tumor

  19. Lipid-polymer hybrid nanoparticles: Development & statistical optimization of norfloxacin for topical drug delivery system

    Directory of Open Access Journals (Sweden)

    Vivek Dave

    2017-12-01

    Full Text Available Poly lactic acid is a biodegradable, biocompatible, and non-toxic polymer, widely used in many pharmaceutical preparations such as controlled release formulations, parenteral preparations, surgical treatment applications, and tissue engineering. In this study, we prepared lipid-polymer hybrid nanoparticles for topical and site targeting delivery of Norfloxacin by emulsification solvent evaporation method (ESE. The design of experiment (DOE was done by using software to optimize the result, and then a surface plot was generated to compare with the practical results. The surface morphology, particle size, zeta potential and composition of the lipid-polymer hybrid nanoparticles were characterized by SEM, TEM, AFM, and FTIR. The thermal behavior of the lipid-polymer hybrid nanoparticles was characterized by DSC and TGA. The prepared lipid-polymer hybrid nanoparticles of Norfloxacin exhibited an average particle size from 178.6 ± 3.7 nm to 220.8 ± 2.3 nm, and showed very narrow distribution with polydispersity index ranging from 0.206 ± 0.36 to 0.383 ± 0.66. The surface charge on the lipid-polymer hybrid nanoparticles were confirmed by zeta potential, showed the value from +23.4 ± 1.5 mV to +41.5 ± 3.4 mV. An Antimicrobial study was done against Staphylococcus aureus and Pseudomonas aeruginosa, and the lipid-polymer hybrid nanoparticles showed potential activity against these two. Lipid-polymer hybrid nanoparticles of Norfloxacin showed the %cumulative drug release of 89.72% in 24 h. A stability study of the optimized formulation showed the suitable condition for the storage of lipid-polymer hybrid nanoparticles was at 4 ± 2 °C/60 ± 5% RH. These results illustrated high potential of lipid-polymer hybrid nanoparticles Norfloxacin for usage as a topical antibiotic drug carriers.

  20. Synthesis, characterization and flocculation activity of novel Fe(OH){sub 3}-polyacrylamide hybrid polymer

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huilong; Cui Jinyan [Department of Chemistry, Dalian University of Technology, Dalian 116023 (China); Jiang Wenfeng, E-mail: dlutjiangwf@yahoo.com.cn [Department of Chemistry, Dalian University of Technology, Dalian 116023 (China)

    2011-11-01

    Highlights: {yields} The preparation of a novel Fe(OH){sub 3}-PAM hybrid polymer flocculant is achieved via free radical solution polymerization. {yields} Flocculation of kaolin suspensions using this novel Fe(OH){sub 3}-PAM hybrid polymer flocculant is revealed in this study. {yields} The statistical model was first applied for calculating the thermodynamic parameters for the kaolin flocculating process. - Abstract: A novel Fe(OH){sub 3}-polyacrylamide inorganic-organic hybrid polymer (FHPAM) was synthesized via free radical solution polymerization initiated by a redox initiation system ((NH{sub 4}){sub 2}S{sub 2}O{sub 8}-NaHSO{sub 3}) in an aqueous medium. Reaction parameters influencing the intrinsic viscosity and the yield of the hybrid polymer, such as initiator concentration, monomer mass fraction, temperature and reaction time were investigated and optimized. The results show that the maximum intrinsic viscosity and up to 94% yields of the hybrid polymer can be achieved using initiator concentration of 0.3% with acrylamide monomer mass fraction of 20% under solution polymerization at 40 deg. C for 7 h. The physicochemical properties of this hybrid flocculant were characterized with TEM, FTIR spectra, TGA, and conductivity. It was found that a chemical bond exists between Fe(OH){sub 3} colloid and polyacrylamide chains in the FHPAM. The application of the hybrid polymer for the treatment of 2.5 g L{sup -1} kaolin suspension indicates that it had an excellent flocculation capacity and its flocculation efficiency was much better than that of commercial available polyacrylamide (PAM) and polymeric ferric sulfate (PFS). The optimal conditions for the flocculation treatment of kaolin suspension were the FHPAM dosage of 40 mg L{sup -1} at pH 7.0. The thermodynamic parameters for the flocculation process were calculated based on a statistical model. Interpretation of the results was given.

  1. Synthesis, characterization and flocculation activity of novel Fe(OH)3-polyacrylamide hybrid polymer

    International Nuclear Information System (INIS)

    Wang Huilong; Cui Jinyan; Jiang Wenfeng

    2011-01-01

    Highlights: → The preparation of a novel Fe(OH) 3 -PAM hybrid polymer flocculant is achieved via free radical solution polymerization. → Flocculation of kaolin suspensions using this novel Fe(OH) 3 -PAM hybrid polymer flocculant is revealed in this study. → The statistical model was first applied for calculating the thermodynamic parameters for the kaolin flocculating process. - Abstract: A novel Fe(OH) 3 -polyacrylamide inorganic-organic hybrid polymer (FHPAM) was synthesized via free radical solution polymerization initiated by a redox initiation system ((NH 4 ) 2 S 2 O 8 -NaHSO 3 ) in an aqueous medium. Reaction parameters influencing the intrinsic viscosity and the yield of the hybrid polymer, such as initiator concentration, monomer mass fraction, temperature and reaction time were investigated and optimized. The results show that the maximum intrinsic viscosity and up to 94% yields of the hybrid polymer can be achieved using initiator concentration of 0.3% with acrylamide monomer mass fraction of 20% under solution polymerization at 40 deg. C for 7 h. The physicochemical properties of this hybrid flocculant were characterized with TEM, FTIR spectra, TGA, and conductivity. It was found that a chemical bond exists between Fe(OH) 3 colloid and polyacrylamide chains in the FHPAM. The application of the hybrid polymer for the treatment of 2.5 g L -1 kaolin suspension indicates that it had an excellent flocculation capacity and its flocculation efficiency was much better than that of commercial available polyacrylamide (PAM) and polymeric ferric sulfate (PFS). The optimal conditions for the flocculation treatment of kaolin suspension were the FHPAM dosage of 40 mg L -1 at pH 7.0. The thermodynamic parameters for the flocculation process were calculated based on a statistical model. Interpretation of the results was given.

  2. Polymer and small molecule based hybrid light source

    Science.gov (United States)

    Choong, Vi-En; Choulis, Stelios; Krummacher, Benjamin Claus; Mathai, Mathew; So, Franky

    2010-03-16

    An organic electroluminescent device, includes: a substrate; a hole-injecting electrode (anode) coated over the substrate; a hole injection layer coated over the anode; a hole transporting layer coated over the hole injection layer; a polymer based light emitting layer, coated over the hole transporting layer; a small molecule based light emitting layer, thermally evaporated over the polymer based light emitting layer; and an electron-injecting electrode (cathode) deposited over the electroluminescent polymer layer.

  3. Continuous cellularization of calcium phosphate hybrid scaffolds induced by plasma polymer activation

    International Nuclear Information System (INIS)

    Bergemann, Claudia; Cornelsen, Matthias; Quade, Antje; Laube, Thorsten; Schnabelrauch, Matthias; Rebl, Henrike; Weißmann, Volker; Seitz, Hermann; Nebe, Barbara

    2016-01-01

    The generation of hybrid materials based on β-tricalcium phosphate (TCP) and various biodegradable polymers like poly(L-lactide-co-D,L-lactide) (PLA) represents a common approach to overcoming the disadvantages of pure TCP devices. These disadvantages lie in TCP's mechanical properties, such as brittleness. The positive characteristic of PLA — improvement of compressive strength of calcium phosphate scaffolds – is diametrically opposed to its cell attractiveness. Therefore, the objective of this work was to optimize osteoblast migration and cellularization inside a three-dimensionally (3D) printed, PLA polymer stabilized TCP hybrid scaffold by a plasma polymer process depositing amino groups via allylamine. MG-63 osteoblastic cells inside the 10 mm hybrid scaffold were dynamically cultivated for 14 days in a 3D model system integrated in a perfusion reactor. The whole TCP/PLA hybrid scaffold was continuously colonized due to plasma polymerized allylamine activation inducing the migration potential of osteoblasts. - Highlights: • Mechanical stabilization of β-tricalcium phosphate scaffolds by PLA infiltration • Hybrid scaffolds with higher cell attraction due to plasma polymerized allylamine • 3D perfusion in vitro model for observation of cell migration inside scaffolds • Enhanced cell migration within plasma polymer coated TCP hybrid scaffolds

  4. Continuous cellularization of calcium phosphate hybrid scaffolds induced by plasma polymer activation

    Energy Technology Data Exchange (ETDEWEB)

    Bergemann, Claudia [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany); Cornelsen, Matthias [University of Rostock, Fluid Technology and Microfluidics, Justus-von-Liebig Weg 6, D-18059 Rostock (Germany); Quade, Antje [Leibniz-Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany); Laube, Thorsten; Schnabelrauch, Matthias [INNOVENT e.V., Biomaterials Department, Pruessingstrasse 27B, D-07745 Jena (Germany); Rebl, Henrike [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany); Weißmann, Volker [Institute for Polymer Technologies (IPT) e.V., Alter Holzhafen 19, D-23966 Wismar (Germany); Seitz, Hermann [University of Rostock, Fluid Technology and Microfluidics, Justus-von-Liebig Weg 6, D-18059 Rostock (Germany); Nebe, Barbara, E-mail: barbara.nebe@med.uni-rostock.de [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany)

    2016-02-01

    The generation of hybrid materials based on β-tricalcium phosphate (TCP) and various biodegradable polymers like poly(L-lactide-co-D,L-lactide) (PLA) represents a common approach to overcoming the disadvantages of pure TCP devices. These disadvantages lie in TCP's mechanical properties, such as brittleness. The positive characteristic of PLA — improvement of compressive strength of calcium phosphate scaffolds – is diametrically opposed to its cell attractiveness. Therefore, the objective of this work was to optimize osteoblast migration and cellularization inside a three-dimensionally (3D) printed, PLA polymer stabilized TCP hybrid scaffold by a plasma polymer process depositing amino groups via allylamine. MG-63 osteoblastic cells inside the 10 mm hybrid scaffold were dynamically cultivated for 14 days in a 3D model system integrated in a perfusion reactor. The whole TCP/PLA hybrid scaffold was continuously colonized due to plasma polymerized allylamine activation inducing the migration potential of osteoblasts. - Highlights: • Mechanical stabilization of β-tricalcium phosphate scaffolds by PLA infiltration • Hybrid scaffolds with higher cell attraction due to plasma polymerized allylamine • 3D perfusion in vitro model for observation of cell migration inside scaffolds • Enhanced cell migration within plasma polymer coated TCP hybrid scaffolds.

  5. Magnetic silica hybrids modified with guanidine containing co-polymers for drug delivery applications

    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, 30, Lenin Avenue, 634500 Tomsk (Russian Federation); Khashirova, Svetlana Yu. [Kabardino-Balkar State University, ul. Chernyshevskogo 173, Nal' chik, 360004 Kabardino-Balkaria (Russian Federation); Rumyantsev, Evgeniy V.; Goncharenko, Alexander A. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000 Ivanovo (Russian Federation)

    2016-07-01

    Guanidine containing co-polymers grafted onto silica nanoparticles to form core-shell structure were prepared by sol-gel method in the presence of γ-Fe{sub 2}O{sub 3} nanoparticles. The morphological features for uncoated and coated silica particles have been characterized with scanning electron microscopy. The results show that the polymer coated silicas exhibit spherical morphology with rough polymeric surface covered by γ-Fe{sub 2}O{sub 3} nanoparticles. The grafting amount of guanidine containing co-polymers evaluated by thermogravimetric analysis was in the range from 17 to 30%. Then, the drug loading properties and cumulative release of silica hybrids modified with guanidine containing co-polymers were evaluated using molsidomine as a model drug. It was shown that after polymer grafting the loading content of molsidomine could reach up to 3.42 ± 0.21 and 2.34 ± 0.14 mg/g respectively. The maximum drug release of molsidomine is achieved at pH 1.6 (approximately 71–75% release at 37 °C), whereas at pH 7.4 drug release is lower (50.4–59.6% release at 37 °C). These results have an important implication that our magneto-controlled silica hybrids modified with guanidine containing co-polymers are promising as drug carriers with controlled behaviour under influence of magnetic field. - Highlights: • Polymer coated silica hybrids containing γ-Fe{sub 2}O{sub 3} were prepared via sol–gel method. • Polymer grafting influences pH-response and surface properties of final products. • Molsidomine as a model drug was effectively loaded into polymer coated silicas. • The drug loading depends on the nature of grafted polymer and its content.

  6. Synthetic Strategies in the Preparation of Polymer/Inorganic Hybrid Nanoparticles

    Science.gov (United States)

    Hood, Matthew A.; Mari, Margherita; Muñoz-Espí, Rafael

    2014-01-01

    This article reviews the recent advances and challenges in the preparation of polymer/inorganic hybrid nanoparticles. We mainly focus on synthetic strategies, basing our classification on whether the inorganic and the polymer components have been formed in situ or ex situ, of the hybrid material. Accordingly, four types of strategies are identified and described, referring to recent examples: (i) ex situ formation of the components and subsequent attachment or integration, either by covalent or noncovalent bonding; (ii) in situ polymerization in the presence of ex situ formed inorganic nanoparticles; (iii) in situ precipitation of the inorganic components on or in polymer structures; and (iv) strategies in which both polymer and inorganic component are simultaneously formed in situ. PMID:28788665

  7. Radiation stable, hybrid, chemical vapor infiltration/preceramic polymer joining of silicon carbide components

    Energy Technology Data Exchange (ETDEWEB)

    Khalifa, Hesham E., E-mail: hesham.khalifa@ga.com [General Atomics, 3550 General Atomics Ct., San Diego 92121, CA (United States); Koyanagi, Takaaki [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge 37831, TN (United States); Jacobsen, George M.; Deck, Christian P.; Back, Christina A. [General Atomics, 3550 General Atomics Ct., San Diego 92121, CA (United States)

    2017-04-15

    This paper reports on a nuclear-grade joining material for bonding of silicon carbide-based components. The joint material is fabricated via a hybrid preceramic polymer, chemical vapor infiltration process. The joint is comprised entirely of β-SiC and results in excellent mechanical and permeability performance. The joint strength, composition, and microstructure have been characterized before and after irradiation to 4.5 dpa at 730 °C in the High Flux Isotope Reactor. The hybrid preceramic polymer-chemical vapor infiltrated joint exhibited complete retention of shear strength and no evidence of microstructural evolution or damage was detected following irradiation.

  8. Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline antimonic acid

    Directory of Open Access Journals (Sweden)

    Beleze Fábio A.

    2001-01-01

    Full Text Available In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline antimonic acid (CAA and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion.

  9. Radiation sterilization of enzyme hybrids with biodegradable polymers

    International Nuclear Information System (INIS)

    Furuta, Masakazu; Oka, Masahito; Hayashi, Toshio

    2002-01-01

    Ionizing radiations, which have already been utilized for the sterilization of medical supplies as well as gas fumigation, should be the final candidate to decontaminate 'hybrid' biomaterials containing bio-active materials including enzymes because irradiation induces neither heat nor substances affecting the quality of the materials and our health. In order to check the feasibility of 60 Co-gamma rays on these materials, we selected commercial proteases including papain and bromelain hybridized with commercial activated chitosan beads and demonstrated that these enzyme-hybrids suspended in water showed the significant radiation durability of more than twice as much as free enzyme solution at 25-kGy irradiation. Enhanced thermal and storage stability of the enzyme hybrids were not affected by the same dose level of irradiation, either, indicating that commercial irradiation sterilization method is applicable to enzyme hybrids without modification

  10. Polymer-Block-Polypeptides and Polymer-Conjugated Hybrid Materials as Stimuli-Responsive Nanocarriers for Biomedical Applications.

    Science.gov (United States)

    John, Johnson V; Johnson, Renjith P; Heo, Min Seon; Moon, Byeong Kyu; Byeon, Seong Jin; Kim, Il

    2015-01-01

    Stimuli-responsive nanocarriers are a class of soft materials that includes natural polymers, synthetic polymers, and polypeptides. Recently, modern synthesis tools such as atom transfer radical polymerization, reversible addition-fragmentation chain transfer polymerization, nitroxide-mediated radical polymerization, ring-opening polymerization of α-amino acid N-carboxyanhydrides, and various "click" chemistry strategies were simultaneously employed for the design and synthesis of nanosized drug delivery vehicles. Importantly, the research focused on the improvement of the nanocarrier targetability and the site-specific, triggered release of therapeutics with high drug loading efficiency and minimal drug leakage during the delivery to specific targets. In this context, nanocarriers responsive to common stimuli such as pH, temperature, redox potential, light, etc. have been widely used for the controlled delivery of therapeutics to pathological sites. Currently, different synthesis and self-assembly strategies improved the drug loading efficacy and targeted delivery of therapeutic agents to the desired site. In particular, polypeptide-containing hybrid materials have been developed for the controlled delivery of therapeutic agents. Therefore, stimuli-sensitive synthetic polypeptide-based materials have been extensively investigated in recent years. This review focuses on recent advances in the development of polymer-block-polypeptides and polymer-conjugated hybrid materials that have been designed and evaluated for various stimuli-responsive drug and gene delivery applications.

  11. Hybrid waste filler filled bio-polymer foam composites for sound absorbent materials

    Science.gov (United States)

    Rus, Anika Zafiah M.; Azahari, M. Shafiq M.; Kormin, Shaharuddin; Soon, Leong Bong; Zaliran, M. Taufiq; Ahraz Sadrina M. F., L.

    2017-09-01

    Sound absorption materials are one of the major requirements in many industries with regards to the sound insulation developed should be efficient to reduce sound. This is also important to contribute in economically ways of producing sound absorbing materials which is cheaper and user friendly. Thus, in this research, the sound absorbent properties of bio-polymer foam filled with hybrid fillers of wood dust and waste tire rubber has been investigated. Waste cooking oil from crisp industries was converted into bio-monomer, filled with different proportion ratio of fillers and fabricated into bio-polymer foam composite. Two fabrication methods is applied which is the Close Mold Method (CMM) and Open Mold Method (OMM). A total of four bio-polymer foam composite samples were produce for each method used. The percentage of hybrid fillers; mixture of wood dust and waste tire rubber of 2.5 %, 5.0%, 7.5% and 10% weight to weight ration with bio-monomer. The sound absorption of the bio-polymer foam composites samples were tested by using the impedance tube test according to the ASTM E-1050 and Scanning Electron Microscope to determine the morphology and porosity of the samples. The sound absorption coefficient (α) at different frequency range revealed that the polymer foam of 10.0 % hybrid fillers shows highest α of 0.963. The highest hybrid filler loading contributing to smallest pore sizes but highest interconnected pores. This also revealed that when highly porous material is exposed to incident sound waves, the air molecules at the surface of the material and within the pores of the material are forced to vibrate and loses some of their original energy. This is concluded that the suitability of bio-polymer foam filled with hybrid fillers to be used in acoustic application of automotive components such as dashboards, door panels, cushion and etc.

  12. Influence of the polymer concentration on the electroluminescence of ZnO nanorod/polymer hybrid light emitting diodes

    Science.gov (United States)

    Zaman, Saima; Zainelabdin, Ahmed; Amin, Gul; Nur, Omer; Willander, Magnus

    2012-09-01

    The effects of the polymer concentration on the performance of hybrid light emitting diodes (LEDs) based on zinc oxide nanorods (ZnO NRs) and poly(9,9-dioctylfluorene) (PFO) were investigated. Various characterization techniques were applied to study the performance of the PFO/ZnO NR hybrid LEDs fabricated with various PFO concentrations. The fabricated hybrid LEDs demonstrated stable rectifying diode behavior, and it was observed that the turn-on voltage of the LEDs is concentration dependent. The measured room temperature electroluminescence (EL) showed that the PFO concentration plays a critical role in the emission spectra of the hybrid LEDs. At lower PFO concentrations of 2-6 mg/ml, the EL spectra are dominated by blue emission. However, by increasing the concentration to more than 8 mg/ml, the blue emission was completely suppressed while the green emission was dominant. This EL behavior was explained by a double trap system of excitons that were trapped in the β-phase and/or in the fluorenone defects in the PFO side. The effects of current injection on the hybrid LEDs and on the EL emission were also investigated. Under a high injection current, a new blue peak was observed in the EL spectrum, which was correlated to the creation of a new chemical species on the PFO chain. The green emission peak was also enhanced with increasing injection current because of the fluorenone defects. These results indicate that the emission spectra of the hybrid LEDs can be tuned by using different polymer concentrations and by varying the current injected into the device.

  13. Near infrared photodetector based on polymer and indium nitride nanorod organic/inorganic hybrids

    International Nuclear Information System (INIS)

    Lai, Wei-Jung; Li, Shao-Sian; Lin, Chih-Cheng; Kuo, Chun-Chiang; Chen, Chun-Wei; Chen, Kuei-Hsien; Chen, Li-Chyong

    2010-01-01

    We propose a nanostructured near infrared photodetector based on indium nitride (InN) nanorod/poly(3-hexylthiophene) hybrids. The current-voltage characteristic of the hybrid device demonstrates the typical p-n heterojunction diode behavior, consisting of p-type polymer and n-type InN nanorods. The device shows a photoresponse range of 900-1260 nm under various reverse biases. An external quantum efficiency of 3.4% at 900 nm operated at -10 V reverse bias was obtained, which is comparable with devices based on lead sulfide and lead selenide hybrid systems.

  14. An analysis of calcium carbonate/polymer hybrid crystals applying contrast variation SANS

    International Nuclear Information System (INIS)

    Endo, Hitoshi; Schwahn, Dietmar; Coelfen, Helmut

    2004-01-01

    The geometry of calcium carbonate (CaCO 3 )/polymer hybrid crystals was investigated by means of the contrast variation small angle neutron scattering. Our sophisticated contrast variation method led to decomposition of the measured scattering intensities into partial scattering functions of each component. These decomposed partial scattering functions gave detailed information on each component in the hybrid particle. Especially, on the basis of the Babinet principle (or incompressibility hypothesis), the comparison of the cross terms led to the relationships of each scattering amplitude. In this way, we could determine the geometry of the hybrid crystals in detail

  15. An analysis of calcium carbonate/polymer hybrid crystals applying contrast variation SANS

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Hitoshi; Schwahn, Dietmar; Coelfen, Helmut

    2004-07-15

    The geometry of calcium carbonate (CaCO{sub 3})/polymer hybrid crystals was investigated by means of the contrast variation small angle neutron scattering. Our sophisticated contrast variation method led to decomposition of the measured scattering intensities into partial scattering functions of each component. These decomposed partial scattering functions gave detailed information on each component in the hybrid particle. Especially, on the basis of the Babinet principle (or incompressibility hypothesis), the comparison of the cross terms led to the relationships of each scattering amplitude. In this way, we could determine the geometry of the hybrid crystals in detail.

  16. Assembling a Lasing Hybrid Material With Supramolecular Polymers and Nanocrystals

    National Research Council Canada - National Science Library

    Li, Leiming

    2003-01-01

    .... In the system containing ZnO nanocrystals as the inorganic component, both phases are oriented in the hybrid material forming an ultraviolet lasing medium with a lower threshold relative to pure ZnO nanocrystals.

  17. Inorganic-organic hybrid polymers for food packaging

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2015-09-01

    Full Text Available packaging application. Numerous hybrid inorganic-organic materials have been developed using low temperature sol-gel chemistry, which enables the tailoring of the nanostructure and the resulting material is often multifunctional, offering a wide range...

  18. Morphology of protein polymer hybrid films studied by AFM and scanning confocal fluorescence microscopy

    NARCIS (Netherlands)

    Foubert, P.; Hannink, J.M.; Köhn, F.; Gronheid, R.; Sommerdijk, N.A.J.M.; Nolte, R.J.M.; Feyter, de S.; Schryver, de F.C.

    2003-01-01

    Protein–polymer hybrids can act as giant monolayer-forming amphiphiles at the air–water interface. Using biotinylated polystyrene (PSb) as the hydrophobic part and streptavidin (SAv) as a hydrophilic end of the giant amphiphile, monolayer formation and subsequent deposition leads to a well defined

  19. Some fundamental and applicative properties of [polymer/nano-SiC] hybrid nanocomposites

    International Nuclear Information System (INIS)

    Kassiba, A; Boucle, J; Makowska-Janusik, M; Errien, N

    2007-01-01

    Hybrid nanocomposites which combine polymer as host matrix and nanocrystals as active elements are promising functional materials for electronics, optics or photonics. In these systems, the physical response is governed by the nanocrystal features (size, surface and defect states), the polymer properties and the polymer-nanocrystal interface. This work reviews some selective nanostructured architectures based on active elements such as silicon carbide (SiC) nanocrystals and polymer host matrices. Beyond an overview of some key properties of the nanocrystals, a main part will be devoted to the electro-optical (EO) properties of SiC based hybrid systems where SiC nanocrystals are embedded in polymer matrices of different chemical nature such as poly-(methylmethacrylate) (PMMA), poly-vinylcarbazole (PVK) or polycarbonate. Using this approach, the organic-inorganic interface effects are emphasised with regard to the dielectric or hole transporting behaviour of PMMA and PVK respectively. These effects are illustrated through different EO responses associated with hybrid composites based on PMMA or PVK

  20. Ultra-thin silicon/electro-optic polymer hybrid waveguide modulators

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Feng; Spring, Andrew M. [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Sato, Hiromu [Department of Molecular and Material Sciences, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Maeda, Daisuke; Ozawa, Masa-aki; Odoi, Keisuke [Nissan Chemical Industries, Ltd., 2-10-1 Tuboi Nishi, Funabashi, Chiba 274-8507 (Japan); Aoki, Isao; Otomo, Akira [National Institute of Information and Communications Technology, 588-2 Iwaoka, Nishi-ku, Kobe 651-2492 (Japan); Yokoyama, Shiyoshi, E-mail: s-yokoyama@cm.kyushu-u.ac.jp [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Department of Molecular and Material Sciences, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan)

    2015-09-21

    Ultra-thin silicon and electro-optic (EO) polymer hybrid waveguide modulators have been designed and fabricated. The waveguide consists of a silicon core with a thickness of 30 nm and a width of 2 μm. The cladding is an EO polymer. Optical mode calculation reveals that 55% of the optical field around the silicon extends into the EO polymer in the TE mode. A Mach-Zehnder interferometer (MZI) modulator was prepared using common coplanar electrodes. The measured half-wave voltage of the MZI with 7 μm spacing and 1.3 cm long electrodes is 4.6 V at 1550 nm. The evaluated EO coefficient is 70 pm/V, which is comparable to that of the bulk EO polymer film. Using ultra-thin silicon is beneficial in order to reduce the side-wall scattering loss, yielding a propagation loss of 4.0 dB/cm. We also investigated a mode converter which couples light from the hybrid EO waveguide into a strip silicon waveguide. The calculation indicates that the coupling loss between these two devices is small enough to exploit the potential fusion of a hybrid EO polymer modulator together with a silicon micro-photonics device.

  1. Some fundamental and applicative properties of [polymer/nano-SiC] hybrid nanocomposites

    Science.gov (United States)

    Kassiba, A.; Bouclé, J.; Makowska-Janusik, M.; Errien, N.

    2007-08-01

    Hybrid nanocomposites which combine polymer as host matrix and nanocrystals as active elements are promising functional materials for electronics, optics or photonics. In these systems, the physical response is governed by the nanocrystal features (size, surface and defect states), the polymer properties and the polymer-nanocrystal interface. This work reviews some selective nanostructured architectures based on active elements such as silicon carbide (SiC) nanocrystals and polymer host matrices. Beyond an overview of some key properties of the nanocrystals, a main part will be devoted to the electro-optical (EO) properties of SiC based hybrid systems where SiC nanocrystals are embedded in polymer matrices of different chemical nature such as poly-(methylmethacrylate) (PMMA), poly-vinylcarbazole (PVK) or polycarbonate. Using this approach, the organic-inorganic interface effects are emphasised with regard to the dielectric or hole transporting behaviour of PMMA and PVK respectively. These effects are illustrated through different EO responses associated with hybrid composites based on PMMA or PVK.

  2. One-pot in situ redox synthesis of hexacyanoferrate/conductive polymer hybrids as lithium-ion battery cathodes.

    Science.gov (United States)

    Wong, Min Hao; Zhang, Zixuan; Yang, Xianfeng; Chen, Xiaojun; Ying, Jackie Y

    2015-09-14

    An efficient and adaptable method is demonstrated for the synthesis of lithium hexacyanoferrate/conductive polymer hybrids for Li-ion battery cathodes. The hybrids were synthesized via a one-pot method, involving a redox-coupled reaction between pyrrole monomers and the Li3Fe(CN)6 precursor. The hybrids showed much better cyclability relative to reported Prussian Blue (PB) analogs.

  3. Conductivity and properties of polysiloxane-polyether cluster-LiTFSI networks as hybrid polymer electrolytes

    Science.gov (United States)

    Boaretto, Nicola; Joost, Christine; Seyfried, Mona; Vezzù, Keti; Di Noto, Vito

    2016-09-01

    This report describes the synthesis and the properties of a series of polymer electrolytes, composed of a hybrid inorganic-organic matrix doped with LiTFSI. The matrix is based on ring-like oligo-siloxane clusters, bearing pendant, partially cross-linked, polyether chains. The dependency of the thermo-mechanic and of the transport properties on several structural parameters, such as polyether chains' length, cross-linkers' concentration, and salt concentration is studied. Altogether, the materials show good thermo-mechanical and electrochemical stabilities, with conductivities reaching, at best, 8·10-5 S cm-1 at 30 °C. In conclusion, the cell performances of one representative sample are shown. The scope of this report is to analyze the correlations between structure and properties in networked and hybrid polymer electrolytes. This could help the design of optimized polymer electrolytes for application in lithium metal batteries.

  4. Hybrid tandem solar cells with depleted-heterojunction quantum dot and polymer bulk heterojunction subcells

    KAUST Repository

    Kim, Taesoo

    2015-10-01

    We investigate hybrid tandem solar cells that rely on the combination of solution-processed depleted-heterojunction colloidal quantum dot (CQD) and bulk heterojunction polymer:fullerene subcells. The hybrid tandem solar cell is monolithically integrated and electrically connected in series with a suitable p-n recombination layer that includes metal oxides and a conjugated polyelectrolyte. We discuss the monolithic integration of the subcells, taking into account solvent interactions with underlayers and associated constraints on the tandem architecture, and show that an adequate device configuration consists of a low bandgap CQD bottom cell and a high bandgap polymer:fullerene top cell. Once we optimize the recombination layer and individual subcells, the hybrid tandem device reaches a VOC of 1.3V, approaching the sum of the individual subcell voltages. An impressive fill factor of 70% is achieved, further confirming that the subcells are efficiently connected via an appropriate recombination layer. © 2015.

  5. Gas-Transport-Property Performance of Hybrid Carbon Molecular Sieve−Polymer Materials

    KAUST Repository

    Das, Mita

    2010-10-06

    High-performance hybrid materials using carbon molecular sieve materials and 6FDA-6FpDA were produced. A detailed analysis of the effects of casting processes and the annealing temperature is reported. Two existing major obstacles, sieve agglomeration and residual stress, were addressed in this work, and subsequently a new membrane formation technique was developed to produce high-performing membranes. The successfully improved interfacial region of the hybrid membranes allows the sieves to increase the selectivity of the membranes above the neat polymer properties. Furthermore, an additional performance enhancement was seen with increased sieve loading in the hybrid membranes, leading to an actual performance above the upper bound for pure polymer membranes. The membranes were also tested under a mixed-gas environment, which further demonstrated promising results. © 2010 American Chemical Society.

  6. Hybrid zinc oxide conjugated polymer bulk heterojunction solar cells

    NARCIS (Netherlands)

    Beek, W.J.E.; Wienk, M.M.; Kemerink, M.; Yang, X.N.; Janssen, R.A.J.

    2005-01-01

    Bulk heterojunction photovoltaic devices based on blends of a conjugated polymer poly[2-methoxy-5-(3‘,7‘-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as electron donor and crystalline ZnO nanoparticles (nc-ZnO) as electron acceptor have been studied. Composite nc-ZnO:MDMO-PPV films were cast

  7. Graphene-polymer-enzyme hybrid nanomaterials for biosensors

    DEFF Research Database (Denmark)

    2016-01-01

    The invention relates to a general chemical method for the synthesis of biocompatible hybrid nanomaterials which can be used in the development of new- type enzyme based biosensors. A one-step facile method is presented, in which polyethylenimine (PEI) serves as both a reducing agent for the redu......The invention relates to a general chemical method for the synthesis of biocompatible hybrid nanomaterials which can be used in the development of new- type enzyme based biosensors. A one-step facile method is presented, in which polyethylenimine (PEI) serves as both a reducing agent...

  8. Self-Assembled CNT-Polymer Hybrids in Single-Walled Carbon Nanotubes Dispersed Aqueous Triblock Copolymer Solutions

    Science.gov (United States)

    Vijayaraghavan, D.; Manjunatha, A. S.; Poojitha, C. G.

    2018-04-01

    We have carried out scanning electron microscopy (SEM), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), electrical conductivity, and 1H NMR studies as a function of temperature on single-walled carbon nanotubes (SWCNTs) dispersed aqueous triblock copolymer (P123) solutions. The single-walled carbon nanotubes in this system aggregate to form bundles, and the bundles aggregate to form net-like structures. Depending on the temperature and phases of the polymer, this system exhibits three different self-assembled CNT-polymer hybrids. We find CNT-unimer hybrid at low temperatures, CNT-micelle hybrid at intermediate temperatures wherein the polymer micelles are adsorbed in the pores of the CNT nets, and another type of CNT-micelle hybrid at high temperatures wherein the polymer micelles are adsorbed on the surface of the CNT bundles. Our DSC thermogram showed two peaks related to these structural changes in the CNT-polymer hybrids. Temperature dependence of the 1H NMR chemical shifts of the molecular groups of the polymer and the AC electrical conductivity of the composite also showed discontinuous changes at the temperatures at which the CNT-polymer hybrid's structural changes are seen. Interestingly, for a higher CNT concentration (0.5 wt.%) in the system, the aggregated polymer micelles adsorbed on the CNTs exhibit cone-like and cube-like morphologies at the intermediate and at high temperatures respectively.

  9. Boosting the ambipolar performance of solution-processable polymer semiconductors via hybrid side-chain engineering.

    Science.gov (United States)

    Lee, Junghoon; Han, A-Reum; Yu, Hojeong; Shin, Tae Joo; Yang, Changduk; Oh, Joon Hak

    2013-06-26

    Ambipolar polymer semiconductors are highly suited for use in flexible, printable, and large-area electronics as they exhibit both n-type (electron-transporting) and p-type (hole-transporting) operations within a single layer. This allows for cost-effective fabrication of complementary circuits with high noise immunity and operational stability. Currently, the performance of ambipolar polymer semiconductors lags behind that of their unipolar counterparts. Here, we report on the side-chain engineering of conjugated, alternating electron donor-acceptor (D-A) polymers using diketopyrrolopyrrole-selenophene copolymers with hybrid siloxane-solubilizing groups (PTDPPSe-Si) to enhance ambipolar performance. The alkyl spacer length of the hybrid side chains was systematically tuned to boost ambipolar performance. The optimized three-dimensional (3-D) charge transport of PTDPPSe-Si with pentyl spacers yielded unprecedentedly high hole and electron mobilities of 8.84 and 4.34 cm(2) V(-1) s(-1), respectively. These results provide guidelines for the molecular design of semiconducting polymers with hybrid side chains.

  10. Linear electro-optical behavior of hybrid nanocomposites based on silicon carbide nanocrystals and polymer matrices

    Science.gov (United States)

    Bouclé, J.; Kassiba, A.; Makowska-Janusik, M.; Herlin-Boime, N.; Reynaud, C.; Desert, A.; Emery, J.; Bulou, A.; Sanetra, J.; Pud, A. A.; Kodjikian, S.

    2006-11-01

    An electro-optical activity has been recently reported for hybrid nanocomposite thin films where inorganic silicon carbide nanocrystals (ncSiC) are incorporated into polymer matrices. The role of the interface SiC polymer is suggested as the origin of the observed second order nonlinear optical susceptibility in the hybrid materials based on poly-(methylmethacrylate) (PMMA) or poly-( N -vinylcarbazole) matrices. In this work, we report an analysis of the electro-optical response of this hybrid system as a function of the ncSiC content and surface state in order to precise the interface effect in the observed phenomenon. Two specific ncSiC samples with similar morphology and different surface states are incorporated in the PMMA matrix. The effective Pockels parameters of the corresponding hybrid nanocomposites have been estimated up to 7.59±0.74pm/V ( 1wt.% of ncSiC in the matrix). The interfacial region ncSiC polymer is found to play the main role in the observed effect. Particularly, the electronic defects on the ncSiC nanocrystal surface modify the interfacial electrical interactions between the two components. The results are interpreted and discussed on the basis of the strong influence of these active centers in the interfacial region at the nanoscale, which are found to monitor the local hyperpolarizabilities and the macroscopic nonlinear optical susceptibilities. This approach allows us to complete the description and understanding of the electro-optical response in the hybrid SiC /polymer systems.

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

    Directory of Open Access Journals (Sweden)

    Susanna Fafenrot

    2017-10-01

    Full Text Available 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.

  12. 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.

  13. Biocompatible multi-walled carbon nanotube–CdTe quantum dot–polymer hybrids for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Baslak, Canan, E-mail: cananbaslak@gmail.com [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Department of Chemistry, Faculty of Science, Selcuk University, 42075 Konya (Turkey); Demirel Kars, Meltem, E-mail: dmeltem@yahoo.com [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Sarayonu Vocational High School, Selcuk University, 42430 Konya (Turkey); Karaman, Mustafa; Kus, Mahmut [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Department of Chemical Engineering, Faculty of Engineering, Selcuk University, 42075 Konya (Turkey); Cengeloglu, Yunus; Ersoz, Mustafa [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Department of Chemistry, Faculty of Science, Selcuk University, 42075 Konya (Turkey)

    2015-04-15

    Herein we report the synthesis of polymer coated quantum dots (QDs)–carbon nanotube composite material with high biocompatibility and low cellular toxicity. The synthesized multi-walled carbon nanotube (MWCNT)–QD-(-poly(glycidyl methacrylate)) (pGMA) hybrids were characterized using X-ray photoelectron spectroscopy, laser scanning confocal microscopy, transmission electron microscopy and scanning electron microscopy. The results showed that quantum dots were well-distributed on nanotube surfaces in high density. The toxicological assessments of QDs and MWCNT–QD–polymer hybrids in human mammary carcinoma cells and their fluorescence imaging in living cell system were carried out. MWCNT–QD–polymer hybrids possess intense red fluorescence signal under confocal microscopy and good fluorescence stability over 6-h exposure in living cell system. The toxicity comparison of QDs and MWCNT–QD–polymer hybrids has shown that the existence of PGMA thin coating on MWCNT–QD hybrid surface decreased the cellular toxicity and increased biocompatibility. - Highlights: • We report that polymer coating of QDs on CNTs increased their biocompatibility by decreasing cellular toxicity. • QD–CNT polymer hybrid material may be proposed as a good diagnostic agent to visualize cancer cells which may be improved as a therapeutic carrier in future. • Coating QDs with polymer seems to be a right choice to be used in medicinal applications both for diagnosis and for therapy.

  14. Biocompatible multi-walled carbon nanotube–CdTe quantum dot–polymer hybrids for medical applications

    International Nuclear Information System (INIS)

    Baslak, Canan; Demirel Kars, Meltem; Karaman, Mustafa; Kus, Mahmut; Cengeloglu, Yunus; Ersoz, Mustafa

    2015-01-01

    Herein we report the synthesis of polymer coated quantum dots (QDs)–carbon nanotube composite material with high biocompatibility and low cellular toxicity. The synthesized multi-walled carbon nanotube (MWCNT)–QD-(-poly(glycidyl methacrylate)) (pGMA) hybrids were characterized using X-ray photoelectron spectroscopy, laser scanning confocal microscopy, transmission electron microscopy and scanning electron microscopy. The results showed that quantum dots were well-distributed on nanotube surfaces in high density. The toxicological assessments of QDs and MWCNT–QD–polymer hybrids in human mammary carcinoma cells and their fluorescence imaging in living cell system were carried out. MWCNT–QD–polymer hybrids possess intense red fluorescence signal under confocal microscopy and good fluorescence stability over 6-h exposure in living cell system. The toxicity comparison of QDs and MWCNT–QD–polymer hybrids has shown that the existence of PGMA thin coating on MWCNT–QD hybrid surface decreased the cellular toxicity and increased biocompatibility. - Highlights: • We report that polymer coating of QDs on CNTs increased their biocompatibility by decreasing cellular toxicity. • QD–CNT polymer hybrid material may be proposed as a good diagnostic agent to visualize cancer cells which may be improved as a therapeutic carrier in future. • Coating QDs with polymer seems to be a right choice to be used in medicinal applications both for diagnosis and for therapy

  15. Investigation of over-moulded hybrid metal/polymer devices

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Tang, Peter Torben

    2006-01-01

    principles, in-process manufacturing technologies, as well as testing methodologies have to be established in order to be able to develop such integrated devices. In this paper an investigation of the bonding between miniaturized metal insert and a polymer matrix is presented. A special demonstrator...... was designed and manufactured by over-moulding and hot-embossing. The bonding strength between the insert and the plastic part was tested by means of a tensile test. A variety of parameters was studied in order to investigate their influence on the bonding: different polymeric and metallic materials, insert...

  16. Nanoporous polymer--clay hybrid membranes for gas separation.

    Science.gov (United States)

    Defontaine, Guillaume; Barichard, Anne; Letaief, Sadok; Feng, Chaoyang; Matsuura, Takeshi; Detellier, Christian

    2010-03-15

    Nanohybrid organo-inorgano clay mineral-polydimethylsiloxane (PDMS) membranes were prepared by the reaction of pure and/or modified natural clay minerals (Sepiolite and montmorillonite) with PDMS in hexane, followed by evaporation of the solvent at 70 degrees C. The membranes were characterized by means of XRD, SEM, ATD-TG and solid state (29)Si magic angle spinning (MAS) and cross-polarization (CP) CP/MAS NMR. The morphology of the membranes depends on the content loading of clay mineral. For low content, the membrane composition is homogeneous, with well dispersed nanoparticles of clay into the polymer matrix, whereas for higher clay content, the membranes are constituted also of a mixture of well dispersed nanoparticles into the polymer, but in the presence of agglomerations of small clay particles. Quantitative (29)Si MAS NMR demonstrated a strong correlation between the clay content of the membrane and the average length of the PDMS chain, indicating that the nanohybrid material is made of clay particles covalently linked to the PDMS structure. This is particularly the case for Sepiolite with has a high density of Q(2) silanol sites. The separation performances of the prepared membranes were tested for CO(2)/CH(4) and O(2)/N(2) mixtures. The observed separation factors showed an increase of the selectivity in the case of CO(2)/CH(4) in comparison with membranes made from PDMS alone under the same conditions. 2009 Elsevier Inc. All rights reserved.

  17. Inorganic-organic hybrid polymer for preparation of affiliating material using electron beam irradiation

    International Nuclear Information System (INIS)

    Chung, Jaeseung; Kim, Seongeun; Kim, Byounggak; Lee, Jongchan; Park, Jihyun; Lee, Byeongcheol

    2011-01-01

    Recently, silver nano materials have gained a lot of attentions in a variety of applications due to the unique biological, optical, and electrical properties. Especially, the antifouling property of these material is considered to be an important character for biomedical field, marine coatings industry, biosensor, and drug delivery. In this study, we design and synthesize the inorganic-organic hybrid polymer for preparation of affiliating materials. Silver nano materials having antifouling property with different shapes are prepared by control the electron beam irradiation conditions. Inorganic-organic hybrid polymer was synthesized and characterized. → Morphology and size controlled nano materials are prepared using electron beam irradiation. → Silver nano materials having various shapes can be used for antifouling material

  18. Chitosan-Based Hyaluronic Acid Hybrid Polymer Fibers as a Scaffold Biomaterial for Cartilage Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Shintarou Yamane

    2010-12-01

    Full Text Available An ideal scaffold material is one that closely mimics the natural environment in the tissue-specific extracellular matrix (ECM. Therefore, we have applied hyaluronic acid (HA, which is a main component of the cartilage ECM, to chitosan as a fundamental material for cartilage regeneration. To mimic the structural environment of cartilage ECM, the fundamental structure of a scaffold should be a three-dimensional (3D system with adequate mechanical strength. We structurally developed novel polymer chitosan-based HA hybrid fibers as a biomaterial to easily fabricate 3D scaffolds. This review presents the potential of a 3D fabricated scaffold based on these novel hybrid polymer fibers for cartilage tissue engineering.

  19. Radiolytic Syntheses of Nanoparticles and Inorganic-Polymer Hybrid Microgels

    International Nuclear Information System (INIS)

    Chen, Q.; Shi, J.; Zhao, R.; Shen, X.

    2010-01-01

    In the second year of the project, we have gotten progress mainly in two directions. Firstly, for the first time, Prussian blue (PB) nanoparticles (NPs) were successfully synthesized by the partly radiolytic reduction of Fe3+ and Fe(CN)63 in the presence of poly(N-vinyl pyrrolidine) (PVP) under N2 atmospheres at room temperature. With the increase of the concentration of PVP, the size and the size distribution of the synthesized quasi-spherical PB NPs decreased obviously, leading to a hypsochromic shift on their peak position of the characteristic absorption. In the experiment, we further found that the smaller ones have a larger capacity to Cs+, suggesting that the application of PB NPs in curing thallotoxicosis may decrease the usage of PB for the patient to great extent. Secondly, through a series of preliminary experiments, we got a clear picture about the one-step radiolytic preparation of inorganic-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by surfactant-free emulsion polymerization. Besides, unpurified N-carbamothioylmethacrylamide was synthesized via the methacrylation of thiourea. These created favorable conditions for the one-step synthesis of metal sulfide-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by -irradiation and surfactant-free emulsion polymerization. (author)

  20. Radiolytic Syntheses of Nanoparticles and Inorganic-Polymer Hybrid Microgels

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.; Shi, J.; Zhao, R.; Shen, X., E-mail: qdchen@pku.edu.cn [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, No. 5, Yiheyuan Load, Haidian District Beijing 100871 (China)

    2010-07-01

    In the second year of the project, we have gotten progress mainly in two directions. Firstly, for the first time, Prussian blue (PB) nanoparticles (NPs) were successfully synthesized by the partly radiolytic reduction of Fe3+ and Fe(CN)63 in the presence of poly(N-vinyl pyrrolidine) (PVP) under N2 atmospheres at room temperature. With the increase of the concentration of PVP, the size and the size distribution of the synthesized quasi-spherical PB NPs decreased obviously, leading to a hypsochromic shift on their peak position of the characteristic absorption. In the experiment, we further found that the smaller ones have a larger capacity to Cs+, suggesting that the application of PB NPs in curing thallotoxicosis may decrease the usage of PB for the patient to great extent. Secondly, through a series of preliminary experiments, we got a clear picture about the one-step radiolytic preparation of inorganic-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by surfactant-free emulsion polymerization. Besides, unpurified N-carbamothioylmethacrylamide was synthesized via the methacrylation of thiourea. These created favorable conditions for the one-step synthesis of metal sulfide-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by -irradiation and surfactant-free emulsion polymerization. (author)

  1. Factors affecting drug encapsulation and stability of lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Cheow, Wean Sin; Hadinoto, Kunn

    2011-07-01

    Lipid-polymer hybrid nanoparticles are polymeric nanoparticles enveloped by lipid layers that combine the highly biocompatible nature of lipids with the structural integrity afforded by polymeric nanoparticles. Recognizing them as attractive drug delivery vehicles, antibiotics are encapsulated in the present work into hybrid nanoparticles intended for lung biofilm infection therapy. Modified emulsification-solvent-evaporation methods using lipid as surfactant are employed to prepare the hybrid nanoparticles. Biodegradable poly (lactic-co-glycolic acid) and phosphatidylcholine are used as the polymer and lipid models, respectively. Three fluoroquinolone antibiotics (i.e. levofloxacin, ciprofloxacin, and ofloxacin), which vary in their ionicity, lipophilicity, and aqueous solubility, are used. The hybrid nanoparticles are examined in terms of their drug encapsulation efficiency, drug loading, stability, and in vitro drug release profile. Compared to polymeric nanoparticles prepared using non-lipid surfactants, hybrid nanoparticles in general are larger and exhibit higher drug loading, except for the ciprofloxacin-encapsulated nanoparticles. Hybrid nanoparticles, however, are unstable in salt solutions, but the stability can be conferred by adding TPGS into the formulation. Drug-lipid ionic interactions and drug lipophilicity play important roles in the hybrid nanoparticle preparation. First, interactions between oppositely charged lipid and antibiotic (i.e. ciprofloxacin) during preparation cause failed nanoparticle formation. Charge reversal of the lipid facilitated by adding counterionic surfactants (e.g. stearylamine) must be performed before drug encapsulation can take place. Second, drug loading and the release profile are strongly influenced by drug lipophilicity, where more lipophilic drug (i.e. levofloxacin) exhibit a higher drug loading and a sustained release profile attributed to the interaction with the lipid coat. Copyright © 2011 Elsevier B.V. All

  2. Hybrid and hierarchical nanoreinforced polymer composites: Computational modelling of structure–properties relationships

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Dai, Gaoming

    2014-01-01

    by using computational micromechanical models. It is shown that while glass/carbon fibers hybrid composites clearly demonstrate higher stiffness and lower weight with increasing the carbon content, they can have lower strength as compared with usual glass fiber polymer composites. Secondary...... nanoreinforcement can drastically increase the fatigue lifetime of composites. Especially, composites with the nanoplatelets localized in the fiber/matrix interface layer (fiber sizing) ensure much higher fatigue lifetime than those with the nanoplatelets in the matrix....

  3. Electronic structure of hybrid interfaces for polymer-based electronics

    International Nuclear Information System (INIS)

    Fahlman, M; Crispin, A; Crispin, X; Henze, S K M; Jong, M P de; Osikowicz, W; Tengstedt, C; Salaneck, W R

    2007-01-01

    The fundamentals of the energy level alignment at anode and cathode electrodes in organic electronics are described. We focus on two different models that treat weakly interacting organic/metal (and organic/organic) interfaces: the induced density of interfacial states model and the so-called integer charge transfer model. The two models are compared and evaluated, mainly using photoelectron spectroscopy data of the energy level alignment of conjugated polymers and molecules at various organic/metal and organic/organic interfaces. We show that two different alignment regimes are generally observed: (i) vacuum level alignment, which corresponds to the lack of vacuum level offsets (Schottky-Mott limit) and hence the lack of charge transfer across the interface, and (ii) Fermi level pinning where the resulting work function of an organic/metal and organic/organic bilayer is independent of the substrate work function and an interface dipole is formed due to charge transfer across the interface. We argue that the experimental results are best described by the integer charge transfer model which predicts the vacuum level alignment when the substrate work function is above the positive charge transfer level and below the negative charge transfer level of the conjugated material. The model further predicts Fermi level pinning to the positive (negative) charge transfer level when the substrate work function is below (above) the positive (negative) charge transfer level. The nature of the integer charge transfer levels depend on the materials system: for conjugated large molecules and polymers, the integer charge transfer states are polarons or bipolarons; for small molecules' highest occupied and lowest unoccupied molecular orbitals and for crystalline systems, the relevant levels are the valence and conduction band edges. Finally, limits and further improvements to the integer charge transfer model are discussed as well as the impact on device design. (topical review)

  4. Thermo-optic characteristics of hybrid polymer/silica microstructured optical fiber: An analytical approach

    Science.gov (United States)

    Sharma, Dinesh Kumar; Sharma, Anurag; Tripathi, Saurabh Mani

    2018-04-01

    Microstructured optical fibers (MOFs) allow a variety of advanced materials to be infiltrated in their air-voids for obtaining the increased fiber functionality, and offering a new versatile platform for developing the compact sensors devices. We aim to investigate the thermal characteristics of high-index core triangular hybrid polymer/silica MOFs with circular air-voids infused with polymer by using the analytical field model [1]. We demonstrate that infiltration of air-voids with polymer, e.g., polydimethylsiloxane (PDMS) can facilitate to tune the fundamental modal properties of MOF such as effective index of the mode, near and the far-field profiles, effective mode area and the numerical aperture over the temperature ranging from 0 °C to 100 °C, for different values of relative air-void ratios. The evolution of the mode shape for a given temperature has been investigated in transition from near-field to far-field regime. We have studied the thermal dependence of splice losses between hybrid MOF and the standard step-index single-mode optical fiber in combination with Fresnel losses. For enhancing the evanescent field interactions, we have evaluated fraction of power associated with fundamental mode of hybrid MOF. We have compared the accuracy of our results with those based on full-vector finite-difference (FD) method, as available in the literature.

  5. Polymer-inorganic hybrid proton conductive membranes: Effect of the interfacial transfer pathways

    International Nuclear Information System (INIS)

    Chen, Pingping; Hao, Lie; Wu, Wenjia; Li, Yifan; Wang, Jingtao

    2016-01-01

    Highlights: • A series of hybrid membranes are prepared using fillers with different structures. • The fillers (0-D, 1-D, and 2-D) are sulfonated to ensure close surface component. • The effect of filler’s structure on microstructure of hydrid membrane is explored. • For single-kind filler series, 2-D filler has the strongest conduction promotion. • The synergy effect of different kinds of fillers is systematacially investigated. - Abstract: For hybrid membrane, the polymer-inorganic interface along filler surface can be facilely created to be distinctive and controllable pathway for mass transfer. Herein, three kinds of fillers are used as inorganic additives including zero-dimensional silica (0-D, SiO_2), one-dimensional halloysite nanotube (1-D, HNT), and two-dimensional graphene oxide (2-D, GO), which are functionalized by sulfonated polymer layer to ensure close surface component. Then the fillers are incorporated into two types of polymer matrixes (phase-separated sulfonated poly(ether ether ketone) and non-phase-separated chitosan) to prepare three series of hybrid membranes with single-kind filler, double-kinds fillers, or triple-kinds fillers, respectively. The microstructures, physicochemical properties, and proton conduction properties (under hydrated and anhydrous conditions) of the membranes are extensively investigated. It is found that (i) for the single-kind filler-filled membranes, 2-D filler has the strongest promotion ability for proton conductivity of membrane due to the constructed wide and long-range pathways for proton transfer; (ii) while for the hybrid membranes with double-kinds fillers, instead of synergistic promotion effect, the fillers cause more tortuous transfer pathways within membranes and then decrease proton conductivity; (iii) the hybrid membranes with triple-kinds fillers exhibit similar behavior but a little higher conductivity than the membranes with double-kinds fillers.

  6. Effect of reduced graphene oxide-carbon nanotubes hybrid nanofillers in mechanical properties of polymer nanocomposites

    Science.gov (United States)

    Sa, Kadambinee; Mahakul, Prakash C.; Subramanyam, B. V. R. S.; Raiguru, Jagatpati; Das, Sonali; Alam, Injamul; Mahanandia, Pitamber

    2018-03-01

    Graphene and carbon nanotubes (CNTs) have tremendous interest as reinforcing fillers due to their excellent physical properties. However, their reinforcing effect in polymer matrix is limited due to agglomeration of graphene and CNTs within the polymer matrix. Mechanical properties by the admixture of reduced graphene oxide (rGO) and CNTs in Poly (methyl methacrylate) (PMMA) prepared by solution mixing method has been investigated. The prepared samples are characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscopy. The hybrid composite shows improvement in the mechanical properties compared to rGO/PMMA and MWCNTs/PMMA composites due to better interaction between rGO-MWCNTs and polymer matrix.

  7. A low cost and hybrid technology for integrating silicon sensors or actuators in polymer microfluidic systems

    International Nuclear Information System (INIS)

    Charlot, Samuel; Gué, Anne-Marie; Tasselli, Josiane; Marty, Antoine; Abgrall, Patrick; Estève, Daniel

    2008-01-01

    This paper describes a new technology permitting a hybrid integration of silicon chips in polymer (PDMS and SU8) microfluidic structures. This two-step technology starts with transferring the silicon device onto a rigid substrate (typically PCB) and planarizing it, and then it proceeds with stacking of the polymer-made fluidic network onto the device. The technology is low cost, based on screen printing and lamination, can be applied to treat large surface areas, and is compatible with standard photolithography and vacuum based approaches. We show, as an example, the integration of a thermal sensor inside channels made of PDMS or SU8. The developed structures had no fluid leaks at the Si/polymer interfaces and the electrical circuit was perfectly tightproof. (note)

  8. Electrochemical sensor for catechol and dopamine based on a catalytic molecularly imprinted polymer-conducting polymer hybrid recognition element.

    Science.gov (United States)

    Lakshmi, Dhana; Bossi, Alessandra; Whitcombe, Michael J; Chianella, Iva; Fowler, Steven A; Subrahmanyam, Sreenath; Piletska, Elena V; Piletsky, Sergey A

    2009-05-01

    One of the difficulties with using molecularly imprinted polymers (MIPs) and other electrically insulating materials as the recognition element in electrochemical sensors is the lack of a direct path for the conduction of electrons from the active sites to the electrode. We have sought to address this problem through the preparation and characterization of novel hybrid materials combining a catalytic MIP, capable of oxidizing the template, catechol, with an electrically conducting polymer. In this way a network of "molecular wires" assists in the conduction of electrons from the active sites within the MIP to the electrode surface. This was made possible by the design of a new monomer that combines orthogonal polymerizable functionality; comprising an aniline group and a methacrylamide. Conducting films were prepared on the surface of electrodes (Au on glass) by electropolymerization of the aniline moiety. A layer of MIP was photochemically grafted over the polyaniline, via N,N'-diethyldithiocarbamic acid benzyl ester (iniferter) activation of the methacrylamide groups. Detection of catechol by the hybrid-MIP sensor was found to be specific, and catechol oxidation was detected by cyclic voltammetry at the optimized operating conditions: potential range -0.6 V to +0.8 V (vs Ag/AgCl), scan rate 50 mV/s, PBS pH 7.4. The calibration curve for catechol was found to be linear to 144 microM, with a limit of detection of 228 nM. Catechol and dopamine were detected by the sensor, whereas analogues and potentially interfering compounds, including phenol, resorcinol, hydroquinone, serotonin, and ascorbic acid, had minimal effect (< or = 3%) on the detection of either analyte. Non-imprinted hybrid electrodes and bare gold electrodes failed to give any response to catechol at concentrations below 0.5 mM. Finally, the catalytic properties of the sensor were characterized by chronoamperometry and were found to be consistent with Michaelis-Menten kinetics.

  9. White light generation tuned by dual hybridization of nanocrystals and conjugated polymers

    International Nuclear Information System (INIS)

    Demir, Hilmi Volkan; Nizamoglu, Sedat; Ozel, Tuncay; Mutlugun, Evren; Huyal, Ilkem Ozge; Sari, Emre; Holder, Elisabeth; Tian Nan

    2007-01-01

    Dual hybridization of highly fluorescent conjugated polymers and highly luminescent nanocrystals (NCs) is developed and demonstrated in multiple combinations for controlled white light generation with high color rendering index (CRI) (> 80) for the first time. The generated white light is tuned using layer-by-layer assembly of CdSe/ZnS core-shell NCs closely packed on polyfluorene, hybridized on near-UV emitting nitride-based light emitting diodes (LEDs). The design, synthesis, growth, fabrication and characterization of these hybrid inorganic-organic white LEDs are presented. The following experimental realizations are reported: (i) layer-by-layer hybridization of yellow NCs (λ PL =580 nm) and blue polyfluorene (λ PL =439 nm) with tristimulus coordinates of (x, y)=(0.31, 0.27), correlated color temperature of T c =6962 K and CRI of R a =53.4; (ii) layer-by-layer assembly of yellow and green NCs (λ PL =580 and 540 nm) and blue polyfluorene (λ PL =439 nm) with (x, y)=(0.23, 0.30), T c =14395 K and R a =65.7; and (iii) layer-by-layer deposition of yellow, green and red NCs (λ PL =580, 540 and 620 nm) and blue polyfluorene (λ PL =439 nm) with (x, y)=(0.38, 0.39), T c =4052 K and R a = 83.0. The CRI is demonstrated to be well controlled and significantly improved by increasing multi-chromaticity of the NC and polymer emitters

  10. Hybrid device based on GaN nanoneedles and MEH-PPV/PEDOT:PSS polymer

    International Nuclear Information System (INIS)

    Shin, Min Jeong; Gwon, Dong-Oh; Lee, Chan-Mi; Lee, Gang Seok; Jeon, In-Jun; Ahn, Hyung Soo; Yi, Sam Nyung; Ha, Dong Han

    2015-01-01

    Highlights: • A hybrid device was demonstrated by using MEH-PPV, PEDOT:PSS, and GaN nanoneedles. • I–V curve of the hybrid device showed its rectification behaviour, similar to a diode. • EL peak originated by the different potential barriers at MEH-PPV and GaN interface. - Abstract: A hybrid device that combines the properties of organic and inorganic semiconductors was fabricated and studied. It incorporated poly[2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as organic polymers and GaN nanoneedles as an inorganic semiconductor. Layers of the two polymers were spin coated on to the GaN nanoneedles. The one peak in the electroluminescence spectrum originated from the MEH-PPV layer owing to the different potential barriers of electrons and holes at its interface with the GaN nanoneedles. However, the photoluminescence spectrum showed peaks due to both GaN nanoneedles and MEH-PPV. Such hybrid structures, suitably developed, might be able to improve the efficiency of optoelectronic devices

  11. Hybrid device based on GaN nanoneedles and MEH-PPV/PEDOT:PSS polymer

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Min Jeong; Gwon, Dong-Oh; Lee, Chan-Mi; Lee, Gang Seok [Department of Applied Science, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Jeon, In-Jun [Department of Nano-semiconductor Engineering, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Ahn, Hyung Soo [Department of Applied Science, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Department of Nano-semiconductor Engineering, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Yi, Sam Nyung, E-mail: snyi@kmou.ac.kr [Department of Applied Science, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Department of Nano-semiconductor Engineering, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Ha, Dong Han [Division of Convergence Technology, Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of)

    2015-08-15

    Highlights: • A hybrid device was demonstrated by using MEH-PPV, PEDOT:PSS, and GaN nanoneedles. • I–V curve of the hybrid device showed its rectification behaviour, similar to a diode. • EL peak originated by the different potential barriers at MEH-PPV and GaN interface. - Abstract: A hybrid device that combines the properties of organic and inorganic semiconductors was fabricated and studied. It incorporated poly[2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as organic polymers and GaN nanoneedles as an inorganic semiconductor. Layers of the two polymers were spin coated on to the GaN nanoneedles. The one peak in the electroluminescence spectrum originated from the MEH-PPV layer owing to the different potential barriers of electrons and holes at its interface with the GaN nanoneedles. However, the photoluminescence spectrum showed peaks due to both GaN nanoneedles and MEH-PPV. Such hybrid structures, suitably developed, might be able to improve the efficiency of optoelectronic devices.

  12. Bioinspired Smart Actuator Based on Graphene Oxide-Polymer Hybrid Hydrogels.

    Science.gov (United States)

    Wang, Tao; Huang, Jiahe; Yang, Yiqing; Zhang, Enzhong; Sun, Weixiang; Tong, Zhen

    2015-10-28

    Rapid response and strong mechanical properties are desired for smart materials used in soft actuators. A bioinspired hybrid hydrogel actuator was designed and prepared by series combination of three trunks of tough polymer-clay hydrogels to accomplish the comprehensive actuation of "extension-grasp-retraction" like a fishing rod. The hydrogels with thermo-creep and thermo-shrinking features were successively irradiated by near-infrared (NIR) to execute extension and retraction, respectively. The GO in the hydrogels absorbed the NIR energy and transformed it into thermo-energy rapidly and effectively. The hydrogel with adhesion or magnetic force was adopted as the "hook" of the hybrid hydrogel actuator for grasping object. The hook of the hybrid hydrogel actuator was replaceable according to applications, even with functional materials other than hydrogels. This study provides an innovative concept to explore new soft actuators through combining response hydrogels and programming the same stimulus.

  13. Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing

    2013-04-01

    Lipid-polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid-polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid-polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification.

  14. Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid–polymer hybrid nanoparticles

    International Nuclear Information System (INIS)

    Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing

    2013-01-01

    Lipid–polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid–polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid–polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification. (paper)

  15. Photovoltaic Performance of Inverted Polymer Solar Cells Using Hybrid Carbon Quantum Dots and Absorption Polymer Materials

    Science.gov (United States)

    Lim, Hwain; Lee, Kyu Seung; Liu, Yang; Kim, Hak Yong; Son, Dong Ick

    2018-05-01

    We report the synthesis and characterization of the carbon quantum dots (C-dots) easily obtained from citric acid and ethanediamine, and also investigated structural, optical and electrical properties. The C-dots have extraordinary optical and electrical features such as absorption of ultraviolet range and effective interface for charge separation and transport in active layer, which make them attractive materials for applications in photovoltaic devices (PV). The C-dots play important roles in charge extraction in the PV structures, they can be synthesized by a simple method and used to insert in active layer of polymer solar cells. In this study, we demonstrate that improve charge transport properties of inverted polymer solar cells (iPSCs) with C-dots and structural, optical and electrical properties of C-dots. As a result, iPSCs with C-dots showed enhancement of more than 30% compared with that of the contrast device in power conversion efficiency.

  16. Fabrication and evaluation of hybrid silica/polymer optical fiber sensors for large strain measurement

    Science.gov (United States)

    Huang, Haiying

    2007-04-01

    Silica-based optical fiber sensors are widely used in structural health monitoring systems for strain and deflection measurement. One drawback of silica-based optical fiber sensors is their low strain toughness. In general, silica-based optical fiber sensors can only reliably measure strains up to 2%. Recently, polymer optical fiber sensors have been employed to measure large strain and deflection. Due to their high optical losses, the length of the polymer optical fibers is limited to 100 meters. In this paper, we present a novel economical technique to fabricate hybrid silica/polymer optical fiber strain sensors for large strain measurement. First, stress analysis of a surface-mounted optical fiber sensor is performed to understand the load distribution between the host structure and the optical fiber in relation to their mechanical properties. Next, the procedure of fabricating a polymer sensing element between two optical fibers is explained. The experimental set-up and the components used in the fabrication process are described in details. Mechanical testing results of the fabricated silica/polymer optical fiber strain sensor are presented.

  17. Zinc oxide nanorods/polymer hybrid heterojunctions for white light emitting diodes

    Science.gov (United States)

    Willander, M.; Nur, O.; Zaman, S.; Zainelabdin, A.; Bano, N.; Hussain, I.

    2011-06-01

    Zinc oxide (ZnO) with its deep level defect emission covering the whole visible spectrum holds promise for the development of intrinsic white lighting sources with no need of using phosphors for light conversion. ZnO nanorods (NRs) grown on flexible plastic as substrate using a low temperature approach (down to 50 °C) were combined with different organic semiconductors to form hybrid junction. White electroluminescence (EL) was observed from these hybrid junctions. The configuration used for the hybrid white light emitting diodes (LEDs) consists of two-layers of polymers on the flexible plastic with ZnO NRs on the top. The inorganic/organic hybrid heterojunction has been fabricated by spin coating the p-type polymer poly (3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT : PSS) for hole injection with an ionization potential of 5.1 eV and poly(9, 9-dioctylfluorene) (PFO) is used as blue emitting material with a bandgap of 3.3 eV. ZnO NRs are grown on top of the organic layers. Two other configurations were also fabricated; these are using a single MEH PPV (red-emitting polymer) instead of the PFO and the third configuration was obtained from a blend of the PFO and the MEH PPV. The white LEDs were characterized by scanning electron microscope, x-ray diffraction (XRD), current-voltage (I-V) characteristics, room temperature photoluminescence (PL) and EL. The EL spectrum reveals a broad emission band covering the range from 420 to 800 nm, and the emissions causing this white luminescence were identified.

  18. Zinc oxide nanorods/polymer hybrid heterojunctions for white light emitting diodes

    International Nuclear Information System (INIS)

    Willander, M; Nur, O; Zaman, S; Zainelabdin, A; Bano, N; Hussain, I

    2011-01-01

    Zinc oxide (ZnO) with its deep level defect emission covering the whole visible spectrum holds promise for the development of intrinsic white lighting sources with no need of using phosphors for light conversion. ZnO nanorods (NRs) grown on flexible plastic as substrate using a low temperature approach (down to 50 0 C) were combined with different organic semiconductors to form hybrid junction. White electroluminescence (EL) was observed from these hybrid junctions. The configuration used for the hybrid white light emitting diodes (LEDs) consists of two-layers of polymers on the flexible plastic with ZnO NRs on the top. The inorganic/organic hybrid heterojunction has been fabricated by spin coating the p-type polymer poly (3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT : PSS) for hole injection with an ionization potential of 5.1 eV and poly(9, 9-dioctylfluorene) (PFO) is used as blue emitting material with a bandgap of 3.3 eV. ZnO NRs are grown on top of the organic layers. Two other configurations were also fabricated; these are using a single MEH PPV (red-emitting polymer) instead of the PFO and the third configuration was obtained from a blend of the PFO and the MEH PPV. The white LEDs were characterized by scanning electron microscope, x-ray diffraction (XRD), current-voltage (I-V) characteristics, room temperature photoluminescence (PL) and EL. The EL spectrum reveals a broad emission band covering the range from 420 to 800 nm, and the emissions causing this white luminescence were identified.

  19. Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications

    Science.gov (United States)

    Kádár, Roland; Abbasi, Mahdi; Figuli, Roxana; Rigdahl, Mikael; Wilhelm, Manfred

    2017-01-01

    The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate) (EBA) nanocomposite hybrids containing graphite nanoplatelets (GnP) and carbon black (CB). The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests. PMID:28336857

  20. Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

    Science.gov (United States)

    Ahmed, Marya

    2017-10-24

    Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

  1. RIR-MAPLE deposition of conjugated polymers and hybrid nanocomposites for application to optoelectronic devices

    International Nuclear Information System (INIS)

    Stiff-Roberts, Adrienne D.; Pate, Ryan; McCormick, Ryan; Lantz, Kevin R.

    2012-01-01

    Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a variation of pulsed laser deposition that is useful for organic-based thin films because it reduces material degradation by selective absorption of infrared radiation in the host matrix. A unique emulsion-based RIR-MAPLE approach has been developed that reduces substrate exposure to solvents and provides controlled and repeatable organic thin film deposition. In order to establish emulsion-based RIR-MAPLE as a preferred deposition technique for conjugated polymer or hybrid nanocomposite optoelectronic devices, studies have been conducted to demonstrate the value added by the approach in comparison to traditional solution-based deposition techniques, and this work will be reviewed. The control of hybrid nanocomposite thin film deposition, and the photoconductivity in such materials deposited using emulsion-based RIR-MAPLE, will also be reviewed. The overall result of these studies is the demonstration of emulsion-based RIR-MAPLE as a viable option for the fabrication of conjugated polymer and hybrid nanocomposite optoelectronic devices that could yield improved device performance.

  2. Studies on Effective Elastic Properties of CNT/Nano-Clay Reinforced Polymer Hybrid Composite

    Science.gov (United States)

    Thakur, Arvind Kumar; Kumar, Puneet; Srinivas, J.

    2016-02-01

    This paper presents a computational approach to predict elastic propertiesof hybrid nanocomposite material prepared by adding nano-clayplatelets to conventional CNT-reinforced epoxy system. In comparison to polymers alone/single-fiber reinforced polymers, if an additional fiber is added to the composite structure, it was found a drastic improvement in resultant properties. In this regard, effective elastic moduli of a hybrid nano composite are determined by using finite element (FE) model with square representative volume element (RVE). Continuum mechanics based homogenization of the nano-filler reinforced composite is considered for evaluating the volumetric average of the stresses and the strains under different periodic boundary conditions.A three phase Halpin-Tsai approach is selected to obtain the analytical result based on micromechanical modeling. The effect of the volume fractions of CNTs and nano-clay platelets on the mechanical behavior is studied. Two different RVEs of nano-clay platelets were used to investigate the influence of nano-filler geometry on composite properties. The combination of high aspect ratio of CNTs and larger surface area of clay platelets contribute to the stiffening effect of the hybrid samples. Results of analysis are validated with Halpin-Tsai empirical formulae.

  3. Semi-crystalline photovoltaic polymers with siloxane-terminated hybrid side-chains

    Institute of Scientific and Technical Information of China (English)

    Yuxiang Li; Seyeong Song; Song Yi Park; Jin Young Kim; Han Young Woo

    2017-01-01

    Three types of semi-cry stalline photovoltaic polymers were synthesized by incorporating a siloxane-terminated organic/inorganic hybrid side-chain and changing the number of fluorine substituents.A branch point away from a polymer main backbone in the siloxane-containing side-chains and the intra-and/or interchain noncovalent coulombic interactions enhance a chain planarity and facile interchain organization.The resulting polymers formed strongly agglomerated films with high roughness,suggesting strong intermolecular interactions.The optical band gap of ca.1.7 eV was measured for all polymers with a pronounced shoulder peak due to tight π-π stacking.With increasing the fluorine substituents,the frontier energy levels decreased and preferential face-on orientation was observed.The siloxane-terminated side-chains and fluorine substitution promoted the intermolecular packing,showing well resolved lamellar scatterings up to(300) for this series of polymers in the grazing incidence wide angle X-ray scattering measurements.The PPsiDTBT,PPsiDTFBT and PPsiDT2 FBT devices showed a power conversion efficiency of 3.16%,4.40%and 5.65%,respectively,by blending with PC71BM.Langevin-type bimolecular charge recombination was similar for three polymeric solar cells.The main loss in the photocurrent generation for PPsiDTBT:PC71BM was interpreted to originate from the trap assisted charge recombination by measuring light-intensity dependent short-circuit current density(JSC) and open-circuit voltage(VOc).Our results provide a new insight into the rational selection of solubilizing substituents for optimizing crystalline interchain packing with appropriate miscibility with PC71 BM for further optimizing polymer solar cells.

  4. Semi-crystalline photovoltaic polymers with siloxane-terminated hybrid side-chains

    Institute of Scientific and Technical Information of China (English)

    Yuxiang Li; Seyeong Song; Song Yi Park; Jin Young Kim; Han Young Woo

    2017-01-01

    Three types of semi-crystalline photovoltaic polymers were synthesized by incorporating a siloxane-terminated organic/inorganic hybrid side-chain and changing the number of fluorine substituents.A branch point away from a polymer main backbone in the siloxane-containing side-chains and the intra-and/or interchain noncovalent coulombic interactions enhance a chain planarity and facile interchain organization.The resulting polymers formed strongly agglomerated films with high roughness,suggesting strong intermolecular interactions.The optical band gap of ca.1.7 eV was measured for all polymers with a pronounced shoulder peak due to tight π-π stacking.With increasing the fluorine substituents,the frontier energy levels decreased and preferential face-on orientation was observed.The siloxane-terminated side-chains and fluorine substitution promoted the intermolecular packing,showing well resolved lamellar scatterings up to (300) for this series of polymers in the grazing incidence wide angle X-ray scattering measurements.The PPsiDTBT,PPsiDTFBT and PPsiDT2FBT devices showed a power conversion efficiency of 3.16%,4.40% and 5.65%,respectively,by blending with PC71BM.Langevin-type bimolecular charge recombination was similar for three polymeric solar cells.The main loss in the photocurrent generation for PPsiDTBT:PC71BM was interpreted to originate from the trap assisted charge recombination by measuring light-intensity dependent short-circuit current density (Jsc) and open-circuit voltage (Voc).Our results provide a new insight into the rational selection of solubilizing substituents for optimizing crystalline interchain packing with appropriate miscibility with PC71BM for further optimizing polymer solar cells.

  5. Functional Hybrid Biomaterials based on Peptide-Polymer Conjugates for Nanomedicine

    Science.gov (United States)

    Shu, Jessica Yo

    The focus of this dissertation is the design, synthesis and characterization of hybrid functional biomaterials based on peptide-polymer conjugates for nanomedicine. Generating synthetic materials with properties comparable to or superior than those found in nature has been a "holy grail" for the materials community. Man-made materials are still rather simplistic when compared to the chemical and structural complexity of a cell. Peptide-polymer conjugates have the potential to combine the advantages of the biological and synthetic worlds---that is they can combine the precise chemical structure and diverse functionality of biomolecules with the stability and processibility of synthetic polymers. As a new family of soft matter, they may lead to materials with novel properties that have yet to be realized with either of the components alone. In order for peptide-polymer conjugates to reach their full potential as useful materials, the structure and function of the peptide should be maintained upon polymer conjugation. The success in achieving desirable, functional assemblies relies on fundamentally understanding the interactions between each building block and delicately balancing and manipulating these interactions to achieve targeted assemblies without interfering with designed structures and functionalities. Such fundamental studies of peptide-polymer interactions were investigated as the nature of the polymer (hydrophilic vs. hydrophobic) and the site of its conjugation (end-conjugation vs. side-conjugation) were varied. The fundamental knowledge gained was then applied to the design of amphiphiles that self-assemble to form stable functional micelles. The micelles exhibited exceptional monodispersity and long-term stability, which is atypical of self-assembled systems. Thus such micelles based on amphiphilic peptide-polymer conjugates may meet many current demands in nanomedicine, in particular for drug delivery of hydrophobic anti-cancer therapeutics. Lastly

  6. Hybrid capacitor with activated carbon electrode, Ni(OH){sub 2} electrode and polymer hydrogel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Nohara, Shinji; Asahina, Toshihide; Wada, Hajime; Furukawa, Naoji; Inoue, Hiroshi; Iwakura, Chiaki [Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); Sugoh, Nozomu; Iwasaki, Hideharu [Kurashiki Research Laboratory, Kuraray Co., Ltd., 2045-1 Sakazu, Kurashiki, Okayama 710-8691 (Japan)

    2006-06-19

    A new hybrid capacitor (HC) cell was assembled using an activated carbon (AC) negative electrode, an Ni(OH){sub 2} positive electrode and a polymer hydrogel electrolyte prepared from crosslinked potassium poly(acrylate) (PAAK) and KOH aqueous solution. The HC cell was characterized compared with an electric double layer capacitor (EDLC) using two AC electrodes and the polymer hydrogel electrolyte. It was found that the HC cell successfully worked in the larger voltage range and exhibited ca. 2.4 times higher capacitance than the EDLC cell. High-rate dischargeability of the HC cell was also superior to that of the EDLC cell. These improved characteristics strongly suggest that the HC cell can be a promising system of capacitors with high energy and power densities. (author)

  7. Hybrid capacitor with activated carbon electrode, Ni(OH) 2 electrode and polymer hydrogel electrolyte

    Science.gov (United States)

    Nohara, Shinji; Asahina, Toshihide; Wada, Hajime; Furukawa, Naoji; Inoue, Hiroshi; Sugoh, Nozomu; Iwasaki, Hideharu; Iwakura, Chiaki

    A new hybrid capacitor (HC) cell was assembled using an activated carbon (AC) negative electrode, an Ni(OH) 2 positive electrode and a polymer hydrogel electrolyte prepared from crosslinked potassium poly(acrylate) (PAAK) and KOH aqueous solution. The HC cell was characterized compared with an electric double layer capacitor (EDLC) using two AC electrodes and the polymer hydrogel electrolyte. It was found that the HC cell successfully worked in the larger voltage range and exhibited ca. 2.4 times higher capacitance than the EDLC cell. High-rate dischargeability of the HC cell was also superior to that of the EDLC cell. These improved characteristics strongly suggest that the HC cell can be a promising system of capacitors with high energy and power densities.

  8. High renewable content sandwich structures based on flax-basalt hybrids and biobased epoxy polymers

    Science.gov (United States)

    Colomina, S.; Boronat, T.; Fenollar, O.; Sánchez-Nacher, L.; Balart, R.

    2014-05-01

    In the last years, a growing interest in the development of high environmental efficiency materials has been detected and this situation is more accentuated in the field of polymers and polymer composites. In this work, green composite sandwich structures with high renewable content have been developed with core cork materials. The base resin for composites was a biobased epoxy resin derived from epoxidized vegetable oils. Hybrid basalt-flax fabrics have been used as reinforcements for composites and the influence of the stacking sequence has been evaluated in order to optimize the appropriate laminate structure for the sandwich bases. Core cork materials with different thickness have been used to evaluate performance of sandwich structures thus leading to high renewable content composite sandwich structures. Results show that position of basalt fabrics plays a key role in flexural fracture of sandwich structures due to differences in stiffness between flax and basalt fibers.

  9. Hybrid nanocomposites based on conducting polymer and silicon nanowires for photovoltaic application

    International Nuclear Information System (INIS)

    Chehata, Nadia; Ltaief, Adnen; Ilahi, Bouraoui; Salem, Bassem; Bouazizi, Abdelaziz; Maaref, Hassen; Baron, Thierry

    2014-01-01

    Hybrid nanocomposites based on a nanoscale combination of organic and inorganic semiconductors are a promising way to enhance the performance of solar cells through a higher aspect ratio of the interface and the good processability of polymers. Nanocomposites are based on a heterojunction network between poly (2-methoxy-5-(2-ethyhexyl-oxy)-p-phenylenevinylene) (MEH-PPV) as an organic electron donor and silicon nanowires (SiNWs) as an inorganic electron acceptor. Nanowires (NWs) seem to be a promising material for this purpose, as they provide a large surface area for contact with the polymer and a designated conducting pathway whilst their volume is low. In this paper, silicon nanowires are introduced by mixing them into the polymer matrix. Hybrid nanocomposites films were deposited onto ITO substrate by spin coating method. Optical properties and photocurrent response were investigated. Charge transfer between the polymer and SiNWs has been demonstrated through photoluminescence measurements. The photocurrent density of ITO/MEH-PPV:SiNWs/Al structures have been obtained by J–V characteristics. The J sc value is about 0.39 µA/cm 2 . - Highlights: • SiNWs synthesis by Vapor–Liquid–Solid (VLS) mechanism. • SiNWs contribution to absorption spectra enhancement of MEH-PPV:SiNWs nanocomposites. • Decrease of PL intensity of MEH-PPV by addition of SiNWs. • Charge transfer process was taken place. • ITO/MEH-PPV:SiNWs/Al structure shows a photovoltaic effect, with a FF of 0.32

  10. Infiltration and Selective Interactions at the Interface in Polymer-Oxide Hybrid Solar Cells

    Science.gov (United States)

    Ferragut, R.; Aghion, S.; Moia, F.; Binda, M.; Canesi, E. V.; Lanzani, G.; Petrozza, A.

    2013-06-01

    Positron annihilation spectroscopy was used to characterize polymer-based hybrid solar cells formed by poly(3-hexylthiophene) (P3HT) finely infiltrated in a porous TiO2 skeleton. A step-change improvement in the device performance is enabled by engineering the hybrid interface by the insertion of a proper molecular interlayer namely 4-mercaptopyridine (4-MP). In order to obtain depth-resolved data, positrons were implanted in the sample using a variable-energy positron beam. The characteristics of the partially filled nanoporous structures were evaluated in terms of the depth profile of the positronium yield and the S-parameter. A quantitative evaluation of the pore filling in the deep region is given from the analysis of Coincidence Doppler Broadening taken at fixed implantation energy. We note a remarkable difference in terms of the positronium yield when the 4-MP interlayer is introduced, which means a better covering of P3HT on the porous surface.

  11. Micro tooling technologies for polymer micro replication: direct, indirect and hybrid process chains

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard

    2009-01-01

    The increasing employment of micro products, of products containing micro parts and of products with micro-structured surfaces calls for mass fabrication technologies based on replication processes. In many cases, a suitable solution is given by the use of polymer micro products, whose production...... and performance of the corresponding micro mould. Traditional methods of micro tooling, such as various machining processes (e.g. micro milling, micro electrical discharge machining) have already reached their limitations with decreasing dimensions of mould inserts and cavities. To this respect, tooling process...... chains based on combination of micro manufacturing processes (defined as hybrid tooling) have been established in order to obtain further features miniaturization and increased accuracy. In this paper, examples and performance of different hybrid tooling approaches as well as challenges, opportunities...

  12. Color optimization of conjugated-polymer/InGaN hybrid white light emitting diodes by incomplete energy transfer

    International Nuclear Information System (INIS)

    Chang, Chi-Jung; Lai, Chun-Feng; Madhusudhana Reddy, P.; Chen, Yung-Lin; Chiou, Wei-Yung; Chang, Shinn-Jen

    2015-01-01

    By using the wavelength conversion method, white light emitting diodes (WLEDs) were produced by applying mixtures of polysiloxane and fluorescent polymers on InGaN based light emitting diodes. UV curable organic–inorganic hybrid materials with high refractive index (1.561), compromised optical, thermal and mechanical properties was used as encapsulants. Red light emitting fluorescent FABD polymer (with 9,9-dioctylfluorene (F), anthracene (A) and 2,1,3-benzothiadiazole (B), and 4,7-bis(2-thienyl)-2,1,3-benzothiadiazole (D) repeating units) and green light emitting fluorescent FAB polymer were used as wavelength converters. The encapsulant/fluorescent polymer mixture and InGaN produce the white light by incomplete energy transfer mechanism. WLEDs with high color rendering index (CRI, about 93), and tunable correlated color temperature (CCT) properties can be produced by controlling the composition and chemical structures of encapsulating polymer and fluorescent polymer in hybrid materials, offering cool-white and neutral-white LEDs. - Highlights: • Highly efficient white light-emitting diodes (WLEDs) were produced. • Conjugated-polymer/InGaN hybrid WLEDs by incomplete energy transfer mechanism. • WLEDs with high color-rendering index and tunable correlated color temperature. • Polysiloxane encapsulant with superior optical, mechanical and thermal properties

  13. Engineering of a polymer layered bio-hybrid heart valve scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Jahnavi, S., E-mail: jani84@gmail.com [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India); Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Kumary, T.V., E-mail: tvkumary@yahoo.com [Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Bhuvaneshwar, G.S., E-mail: gs.bhuvnesh@gmail.com [Trivitron Innovation Centre, Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, TN (India); Natarajan, T.S., E-mail: tsniit@gmail.com [Conducting Polymer laboratory, Department of Physics, Indian Institute of Technology, Madras, Chennai 600036, TN (India); Verma, R.S., E-mail: vermars@iitm.ac.in [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India)

    2015-06-01

    Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients. With advances in tissue engineering, attempts have been made to fabricate valves with regenerative potential using various polymers, decellularized tissues and hybrid scaffolds. To engineer an ideal heart valve, decellularized bovine pericardium extracellular matrix (DBPECM) is an attractive biocompatible scaffold but has weak mechanical properties and rapid degradation. However, DBPECM can be modified with synthetic polymers to enhance its mechanical properties. In this study, we developed a Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties. Surface and functional studies demonstrated integration of PCL-CH to the DBPECM with enhanced bio and hemocompatibility. This engineered Bio-Hybrid scaffold exhibited most of the physical, biochemical and functional properties of the native valve that makes it an ideal scaffold for fabrication of cardiac valve with regenerative potential. - Highlights: • A Bio-Hybrid scaffold was fabricated with PCL-CH blend and DBPECM. • PCL-CH functionally interacted with decellularized matrix without cross linking. • Modified scaffold exhibited mechanical properties similar to native heart valve. • Supported better fibroblast and endothelial cell adhesion and proliferation. • The developed scaffold can be utilized for tissue engineering of heart valve.

  14. White light generation tuned by dual hybridization of nanocrystals and conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Demir, Hilmi Volkan [Devices and Sensors Group and Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Nizamoglu, Sedat [Devices and Sensors Group and Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Ozel, Tuncay [Devices and Sensors Group and Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Mutlugun, Evren [Devices and Sensors Group and Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Huyal, Ilkem Ozge [Devices and Sensors Group and Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Sari, Emre [Devices and Sensors Group and Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Holder, Elisabeth [Functional Polymers Group and Institute of Polymer Technology, University of Wuppertal, Gaussstrasse 20, D-42097 Wuppertal (Germany); Tian Nan [Functional Polymers Group and Institute of Polymer Technology, University of Wuppertal, Gaussstrasse 20, D-42097 Wuppertal (Germany)

    2007-10-15

    Dual hybridization of highly fluorescent conjugated polymers and highly luminescent nanocrystals (NCs) is developed and demonstrated in multiple combinations for controlled white light generation with high color rendering index (CRI) (> 80) for the first time. The generated white light is tuned using layer-by-layer assembly of CdSe/ZnS core-shell NCs closely packed on polyfluorene, hybridized on near-UV emitting nitride-based light emitting diodes (LEDs). The design, synthesis, growth, fabrication and characterization of these hybrid inorganic-organic white LEDs are presented. The following experimental realizations are reported: (i) layer-by-layer hybridization of yellow NCs ({lambda}{sub PL}=580 nm) and blue polyfluorene ({lambda}{sub PL}=439 nm) with tristimulus coordinates of (x, y)=(0.31, 0.27), correlated color temperature of T{sub c}=6962 K and CRI of R{sub a}=53.4; (ii) layer-by-layer assembly of yellow and green NCs ({lambda}{sub PL}=580 and 540 nm) and blue polyfluorene ({lambda}{sub PL}=439 nm) with (x, y)=(0.23, 0.30), T{sub c}=14395 K and R{sub a}=65.7; and (iii) layer-by-layer deposition of yellow, green and red NCs ({lambda}{sub PL}=580, 540 and 620 nm) and blue polyfluorene ({lambda}{sub PL}=439 nm) with (x, y)=(0.38, 0.39), T{sub c}=4052 K and R{sub a}= 83.0. The CRI is demonstrated to be well controlled and significantly improved by increasing multi-chromaticity of the NC and polymer emitters.

  15. Influence of cationic lipid concentration on properties of lipid–polymer hybrid nanospheres for gene delivery

    Directory of Open Access Journals (Sweden)

    Bose RJC

    2015-09-01

    Full Text Available Rajendran JC Bose,1,2 Yoshie Arai,1 Jong Chan Ahn,1 Hansoo Park,2 Soo-Hong Lee11Department of Biomedical Science, College of Life Science, CHA University, Seongnam, 2Department of Integrative Engineering, Chung-Ang University, Seoul, South Korea Abstract: Nanoparticles have been widely used for nonviral gene delivery. Recently, cationic hybrid nanoparticles consisting of two different materials were suggested as a promising delivery vehicle. In this study, nanospheres with a poly(D,l-lactic-co-glycolic acid (PLGA core and cationic lipid shell were prepared, and the effect of cationic lipid concentrations on the properties of lipid polymer hybrid nanocarriers investigated. Lipid–polymer hybrid nanospheres (LPHNSs were fabricated by the emulsion-solvent evaporation method using different concentrations of cationic lipids and characterized for size, surface charge, stability, plasmid DNA-binding capacity, cytotoxicity, and transfection efficiency. All LPHNSs had narrow size distribution with positive surface charges (ζ-potential 52–60 mV, and showed excellent plasmid DNA-binding capacity. In vitro cytotoxicity measurements with HEK293T, HeLa, HaCaT, and HepG2 cells also showed that LPHNSs exhibited less cytotoxicity than conventional transfection agents, such as Lipofectamine and polyethyleneimine–PLGA. As cationic lipid concentrations increased, the particle size of LPHNSs decreased while their ζ-potential increased. In addition, the in vitro transfection efficiency of LPHNSs increased as lipid concentration increased. Keywords: core–shell hybrid nanospheres, lipid concentration, surface modification, low cytotoxicity, transfection efficiency

  16. Mass optimization of a small pressure vessel using metal/FRP (fiber reinforced polymers) hybrid structures

    International Nuclear Information System (INIS)

    Nisar, J.A.; Abdullah, A.N.; Iqbal, N.

    2004-01-01

    In hybrid pressure vessels, composite (Fiber) is wound over a metallic liner (Steel/Aluminum) in hoop direction. In this concept of hybrid pressure vessel structure, metallic liner takes all the axial loads and fiber reinforced polymers (FRP/sub s/) takes load in circumferential (Hoop) direction. Hybrid structures combine the relatively high shear stiffness and ductility of metal alloy with high specific stiffness, strength and fatigue properties of FRP/sub s/. The relatively simple methods for producing hybrid structures circumvent the need for the complex and expensive equipment that is used for advanced composites processing. This paper presents an efficient way of designing a hybrid pressure vessel where prime concern is weight reduction over an equivalent aluminum structure and investigates various methodologies regarding combinations of metals and FRP/sub s/ for optimization of a given pressure vessel. For this purpose we adopted two different methods of simulation one is computer simulation using ANSYS and other is experimental verification by hydrostatic testing of manufactured pressure vessel. Two different pressure vessels one with aluminum liner and other with steel liner were fabricated. Kevlar 49/epoxy was wrapped around the liners in hoop direction. Both the pressure vessels were put into hydrostatic test. Strains were measured during the test and then converted into corresponding stresses. Results of hydrostatic test were quite in favor of the ANSYS results. In this way we have successfully designed, manufactured and tested the Hybrid pressure vessel saving almost 40% weight in case of aluminum liner and 43.6% in case of steel liner. (author)

  17. Ordered mesoporous polymer-silica hybrid nanoparticles as vehicles for the intracellular controlled release of macromolecules.

    Science.gov (United States)

    Kim, Tae-Wan; Slowing, Igor I; Chung, Po-Wen; Lin, Victor Shang-Yi

    2011-01-25

    A two-dimensional hexagonal ordered mesoporous polymer-silica hybrid nanoparticle (PSN) material was synthesized by polymerization of acrylate monomers on the surface of SBA-15 mesoporous silica nanoparticles. The structure of the PSN material was analyzed using a series of different techniques, including transmission electron microscopy, powder X-ray diffraction, and N(2) sorption analysis. These structurally ordered mesoporous polymer-silica hybrid nanoparticles were used for the controlled release of membrane-impermeable macromolecules inside eukaryotic cells. The cellular uptake efficiency and biocompatibility of PSN with human cervical cancer cells (HeLa) were investigated. Our results show that the inhibitory concentration (IC(50)) of PSN is very high (>100 μg/mL per million cells), while the median effective concentration for the uptake (EC(50)) of PSN is low (EC(50) = 4.4 μg/mL), indicating that PSNs are fairly biocompatible and easily up-taken in vitro. A membrane-impermeable macromolecule, 40 kDa FITC-Dextran, was loaded into the mesopores of PSNs at low pH. We demonstrated that the PSN material could indeed serve as a transmembrane carrier for the controlled release of FITC-Dextran at the pH level inside live HeLa cells. We believe that further developments of this PSN material will lead to a new generation of nanodevices for intracellular controlled delivery applications.

  18. Synthesis and properties of imidazole-grafted hybrid inorganic-organic polymer membranes

    International Nuclear Information System (INIS)

    Li Siwen; Zhou Zhen; Liu Meilin; Li Wen; Ukai, Junzo; Hase, Kohei; Nakanishi, Masatsugu

    2006-01-01

    Imidazole rings were grafted on alkoxysilane with a simple nucleophilic substitute reaction to form hybrid inorganic-organic polymers with imidazole rings. Proton exchange membranes (PEM) based on these hybrid inorganic-organic polymers and H 3 PO 4 exhibit high proton conductivity and high thermal stability in an atmosphere of low relative humidity. The grafted imidazole rings improved the proton conductivity of the membranes in the high temperature range. It is found that the proton conductivities increase with H 3 PO 4 content and temperature, reaching 3.2 x 10 -3 S/cm at 110 deg. C in a dry atmosphere for a membrane with 1 mole of imidazole ring and 7 moles of H 3 PO 4 . The proton conductivity increases with relative humidity (RH) as well, reaching 4.3 x 10 -2 S/cm at 110 deg. C when the RH is increased to about 20%. Thermogravimetric analysis (TGA) indicates that these membranes are thermally stable up to 250 deg. C in dry air, implying that they have a good potential to be used as the membranes for high-temperature PEM fuel cells

  19. Preparation and Properties of Polymer/Vermiculite Hybrid Superabsorbent Reinforced by Fiber for Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Fayang Jin

    2014-01-01

    Full Text Available A series of polymer/clay hybrid superabsorbent composites (SACFs comprising acrylamide, acrylic acid, sodium 2-acrylamido-tetradecyl sulfonate, fiber, and vermiculite by in situ intercalation and exfoliated method was successfully synthesized. The structure of SACFs was characterized by IR, SXRD, and SEM measurements. Much notable absorbency for SACF-2 was observed compared to that for SACF-1 in the absence of hydrophobic group in the high cationic solution due to the alkyl carbon chain and sulfonic acid group of hydrophobic moistures protecting the cations from attacking the carboxylate groups. What is more, high temperature fiber which acts as bridge connection for the polymeric network structure enhanced both toughness and strength for SACF-4 in the harsh conditions. At the total dissolved substance of 212000 mg/L for Tarim Basin injected water and the temperature of 120°C, desired absorbency as well as water retaining property for SACF-4 was observed during the long period of thermal ageing. Core flooding experiments demonstrated that SACFs could migrate as amoeba in the porous medium and accumulated in the narrow channel to adjust injection profile, promoting the subsequent water diverting into the unswept zones. Finally, characteristic parameters for SACFs calculated from flooding experiment further confirmed these polymer/clay hybrid composites reinforced by fiber would have robust application in the mature oilfield for profile control.

  20. Mechanistic profiling of the siRNA delivery dynamics of lipid-polymer hybrid nanoparticles

    DEFF Research Database (Denmark)

    Colombo, Stefano; Cun, Dongmei; Remaut, Katrien

    2015-01-01

    Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(dl-lactic-co-glycolic acid) (PLGA) nano...... of transfection-competent siRNA-DOTAP lipoplexes from the LPNs. Based on these results, we suggest a model for the nanostructural characteristics of the LPNs, in which the siRNA is organized in lamellar superficial assemblies and/or as complexes entrapped in the polymeric matrix.......Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(dl-lactic-co-glycolic acid) (PLGA......) nanocarriers modified with the cationic lipid dioleoyltrimethyl-ammoniumpropane (DOTAP). A library of siRNA-loaded LPNs was prepared by systematically varying the nitrogen-to-phosphate (N/P) ratio. Atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM) combined with small angle X...

  1. Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications

    Directory of Open Access Journals (Sweden)

    Roland Kádár

    2017-01-01

    Full Text Available The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate (EBA nanocomposite hybrids containing graphite nanoplatelets (GnP and carbon black (CB. The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests.

  2. Application of hybrid organic/inorganic polymers as coatings on metallic substrates

    Science.gov (United States)

    Augustinho, T. R.; Motz, G.; Ihlow, S.; Machado, R. A. F.

    2016-09-01

    Acrylic polymers, particularly poly (methyl methacrylate) (PMMA), have certain specific properties, such as good film formation, transparency, and good mechanical properties, which have been widely used in paints, coatings and adhesives. However, the limited chemical and physical stability of these pure polymers limits their applications when exposed to hostile conditions, as in ship hulls, for example. A suitable way to enhance PMMA properties is the addition of silicon polymers with very good protective characteristics. In this study, a PMMA and HTT 1800 (commercial silazane) copolymer were applied on metallic substrate and compared to pure PMMA and HTT 1800. All the materials were applied as coatings. They were applied on stainless steel via dip-coating to investigate the coating properties. Thermal cycling was employed to analyze coating durability at high temperatures (50 °C to 600 °C). Optical microscopy (OM) and scanning electron microscopy (SEM) were used to characterize the coated surfaces, and the adhesion of pure PMMA, pure HTT 1800 and PMMA/HTT 1800 coatings on metallic substrate was investigated by Cross-Cut-Test (ASTM D 3359). The sessile drop method was used to determine the contact angle. PMMA coatings presented complete degradation from 250 °C, while hybrid coatings of PMMA and HTT 1800 have good protection until 400 °C. The adherence of the coating on metallic substrate showed improvement in all synthesized materials when compared to pure PMMA, obtaining the best adherence possible. The contact angle test showed that the hydrophobicity of the hybrid coatings is higher than that of the pure coatings.

  3. Folate-modified lipid–polymer hybrid nanoparticles for targeted paclitaxel delivery

    Directory of Open Access Journals (Sweden)

    Zhang L

    2015-03-01

    Full Text Available Linhua Zhang,1 Dunwan Zhu,1 Xia Dong,1 Hongfan Sun,1 Cunxian Song,1 Chun Wang,2 Deling Kong1 1Tianjin Key Laboratory of Biomaterials, Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, People’s Republic of China; 2Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA Abstract: The purpose of this study was to develop a novel lipid–polymer hybrid drug carrier comprised of folate (FA modified lipid-shell and polymer-core nanoparticles (FLPNPs for sustained, controlled, and targeted delivery of paclitaxel (PTX. The core-shell NPs consist of 1 a poly(ε-caprolactone hydrophobic core based on self-assembly of poly(ε-caprolactone–poly(ethylene glycol–poly(ε-caprolactone (PCL-PEG-PCL amphiphilic copolymers, 2 a lipid monolayer formed with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol-2000] (DSPE-PEG2000, 3 a targeting ligand (FA on the surface, and were prepared using a thin-film hydration and ultrasonic dispersion method. Transmission electron microscopy and dynamic light scattering analysis confirmed the coating of the lipid monolayer on the hydrophobic polymer core. Physicochemical characterizations of PTX-loaded FLPNPs, such as particle size and size distribution, zeta potential, morphology, drug loading content, encapsulation efficiency, and in vitro drug release, were also evaluated. Fluorescent microscopy proved the internalization efficiency and targeting ability of the folate conjugated on the lipid monolayer for the EMT6 cancer cells which overexpress folate receptor. In vitro cytotoxicity assay demonstrated that the cytotoxic effect of PTX-loaded FLPNPs was lower than that of Taxol®, but higher than that of PTX-loaded LPNPs (without folate conjugation. In EMT6 breast tumor model, intratumoral administration of PTX-loaded FLPNPs showed similar antitumor efficacy but low toxicity compared to Taxol®. More

  4. Effect of hybrid carbon nanotubes-bimetallic composite particles on the performance of polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun-Young [Department of Material Processing, Korea Institute of Materials Science, Changwon 641-831 (Korea); Division of Applied Chemical Engineering, Department of Polymer Engineering, Pukyong National University, Busan 608-739 (Korea); Kim, Whi-Dong; Kim, Soo H. [Department of Nanosystem and Nanoprocess Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea); Kim, Do-Geun; Kim, Jong-Kuk; Jeong, Yong-Soo; Kang, Jae-Wook [Department of Material Processing, Korea Institute of Materials Science, Changwon 641-831 (Korea); Kim, Joo Hyun [Division of Applied Chemical Engineering, Department of Polymer Engineering, Pukyong National University, Busan 608-739 (Korea); Lee, Jae Keun [School of Mechanical Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea)

    2010-05-15

    Hybrid carbon nanotubes-bimetallic composite nanoparticles with sea urchin-like structures (SU-CNTs) were introduced to bulk heterojunction polymer-fullerene solar cells to improve their performance. The SU-CNTs were composed of multi-walled CNTs, which were grown radially over the entire surface of the bimetallic nanoparticles composed of Ni and Al. SU-CNTs with a precisely controlled length of {proportional_to}200{+-}40 nm were dispersed homogenously in a polymer active layer. Compared with a pristine device (i.e., without SU-CNTs), the SU-CNTs-doped organic photovoltaic (OPV) cells showed an improved short-circuit current density and power conversion efficiency from 7.5 to 9.5 mA/cm{sup 2} and 2.1{+-}0.1% to 2.2{+-}0.2% (max. 2.5%), respectively. The specially designed SU-CNTs have strong potential as an effective exciton dissociation medium in the polymer active layer to enhance the performance of organic solar cells. (author)

  5. Largely enhanced thermal and mechanical properties of polymer nanocomposites via incorporating C60@graphene nanocarbon hybrid

    International Nuclear Information System (INIS)

    Song, Ping’an; Liu, Lina; Yu, Youming; Huang, Guobo; Guo, Qipeng

    2013-01-01

    Although considerable progress has been achieved to create advanced polymer nanocomposites using nanocarbons including fullerene (C 60 ) and graphene, it remains a major challenge to effectively disperse them in a polymer matrix and to fully exert their extraordinary properties. Here we report a novel approach to fabricate the C 60 @graphene nanocarbon hybrid (C 60 : ∼47.9 wt%, graphene: ∼35.1%) via three-step reactions. The presence of C 60 on a graphene sheet surface can effectively prevent the aggregation of the latter which in turn helps the dispersion of the former in a polymer matrix during melt-processing. C 60 @graphene is found to be uniformly dispersed in a polypropylene (PP) matrix. Compared with pristine C 60 or graphene, C 60 @graphene further improves the thermal stability and mechanical properties of PP. The incorporation of 2.0 wt% C 60 @graphene (relative to PP) can remarkably increase the initial degradation temperature by around 59 ° C and simultaneously enhance the tensile strength and Young’s modulus by 67% and 76%, respectively, all of which are higher than those of corresponding PP/C 60 (graphene) nanocomposites. These significant performance improvements are mainly due to the free-radical-trapping effect of C 60 , and the thermal barrier and reinforcing effects of graphene nanosheets as well as the effective stress load transfer. This work provides a new methodology to design multifunctional nanohybrids for creating advanced materials. (paper)

  6. Optical studies of photoactive states in mixed organic-inorganic hybrid perovskites stabilized in polymers

    Science.gov (United States)

    Kardynal, Beata; Xi, Lifei; Salim, Teddy; Borghardt, Sven; Stoica, Toma; Lam, Yeng Ming

    2015-03-01

    Mixed organic-inorganic hybrid perovskites MAX-PbY2(X,Y =I, Br,Cl) have been demonstrated as very attractive materials for absorbers of solar cells and active layers of light emitting diodes and optically driven lasers. The bandgap of the perovskites can be tuned by mixing halogen atoms in different ratios. In this presentation we study mixed MAX-PbY2(X,Y =I, Br, Cl) particles synthesized directly in protective polymer matrices as light emitters. Both, time integrated and time resolved photoluminescence have been used to study the materials. So synthesized MAX-PbX2 are very stable when measured at room temperature and in air with radiative recombination of photogenerated carriers as the main decay path. In contrast, MAX-PbY2 with mixed halogen atoms display luminescence from sub-bandgap states which saturate at higher excitation levels. The density of these states depends on the used polymer matrix and increases upon illumination. We further compare the MAX-PbY2 synthesized in polymers and as films and show that these states are inherent to the material rather than its microstructure. This works has been supported by EU NWs4LIGHT grant.

  7. Color tunable hybrid light-emitting diodes based on perovskite quantum dot/conjugated polymer

    Science.gov (United States)

    Germino, José C.; Yassitepe, Emre; Freitas, Jilian N.; Santiago, Glauco M.; Bonato, Luiz Gustavo; de Morais, Andréia; Atvars, Teresa D. Z.; Nogueira, Ana F.

    2017-08-01

    Inorganic organic metal halide perovskite materials have been investigated for several technological applications, such as photovoltaic cells, lasers, photodetectors and light emitting diodes (LEDs), either in the bulk form or as colloidal nanoparticles. Recently, all inorganic Cesium Lead Halide (CsPbX3, X=Cl,Br, I) perovskite quantum dots (PQDs) were reported with high photoluminescence quantum yield with narrow emission lines in the visible wavelengths. Here, green-emitting perovskite quantum dots (PQDs) prepared by a synthetic method based on a mixture of oleylamine and oleic acid as surfactants were applied in the electroluminescent layer of hybrid LEDs in combination with two different conjugated polymers: polyvinylcarbazole (PVK) or poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO). The performance of the diodes and the emission color tuning upon dispersion of different concentrations of the PQDs in the polymer matrix is discussed. The presented approach aims at the combination of the optical properties of the PQDs and their interaction with wide bandgap conjugated polymers, associated with the solution processing ability of these materials.

  8. Lipid-polymer hybrid nanoparticles as a new generation therapeutic delivery platform: a review.

    Science.gov (United States)

    Hadinoto, Kunn; Sundaresan, Ajitha; Cheow, Wean Sin

    2013-11-01

    Lipid-polymer hybrid nanoparticles (LPNs) are core-shell nanoparticle structures comprising polymer cores and lipid/lipid-PEG shells, which exhibit complementary characteristics of both polymeric nanoparticles and liposomes, particularly in terms of their physical stability and biocompatibility. Significantly, the LPNs have recently been demonstrated to exhibit superior in vivo cellular delivery efficacy compared to that obtained from polymeric nanoparticles and liposomes. Since their inception, the LPNs have advanced significantly in terms of their preparation strategy and scope of applications. Their preparation strategy has undergone a shift from the conceptually simple two-step method, involving preformed polymeric nanoparticles and lipid vesicles, to the more principally complex, yet easier to perform, one-step method, relying on simultaneous self-assembly of the lipid and polymer, which has resulted in better products and higher production throughput. The scope of LPNs' applications has also been extended beyond single drug delivery for anticancer therapy, to include combinatorial and active targeted drug deliveries, and deliveries of genetic materials, vaccines, and diagnostic imaging agents. This review details the current state of development for the LPNs preparation and applications from which we identify future research works needed to bring the LPNs closer to its clinical realization. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Modeling and simulation of surfactant-polymer flooding using a new hybrid method

    Science.gov (United States)

    Daripa, Prabir; Dutta, Sourav

    2017-04-01

    Chemical enhanced oil recovery by surfactant-polymer (SP) flooding has been studied in two space dimensions. A new global pressure for incompressible, immiscible, multicomponent two-phase porous media flow has been derived in the context of SP flooding. This has been used to formulate a system of flow equations that incorporates the effect of capillary pressure and also the effect of polymer and surfactant on viscosity, interfacial tension and relative permeabilities of the two phases. The coupled system of equations for pressure, water saturation, polymer concentration and surfactant concentration has been solved using a new hybrid method in which the elliptic global pressure equation is solved using a discontinuous finite element method and the transport equations for water saturation and concentrations of the components are solved by a Modified Method Of Characteristics (MMOC) in the multicomponent setting. Numerical simulations have been performed to validate the method, both qualitatively and quantitatively, and to evaluate the relative performance of the various flooding schemes for several different heterogeneous reservoirs.

  10. Hybrid scaffold bearing polymer-siloxane Schiff base linkage for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Bindu P., E-mail: bindumelekkuttu@gmail.com; Gangadharan, Dhanya; Mohan, Neethu; Sumathi, Babitha; Nair, Prabha D., E-mail: pdnair49@gmail.com

    2015-07-01

    Scaffolds that can provide the requisite biological cues for the fast regeneration of bone are highly relevant to the advances in tissue engineering and regenerative medicine. In the present article, we report the fabrication of a chitosan–gelatin–siloxane scaffold bearing interpolymer-siloxane Schiff base linkage, through a single-step dialdehyde cross-linking and freeze-drying method using 3-aminopropyltriethoxysilane as the siloxane precursor. Swelling of the scaffolds in phosphate buffered saline indicates enhancement with increase in siloxane concentration, whereas compressive moduli of the wet scaffolds reveal inverse dependence, owing to the presence of siloxane, rich in silanol groups. It is suggested that through the strategy of dialdehyde cross-linking, a limiting siloxane loading of 20 wt.% into a chitosan-gelatin matrix should be considered ideal for bone tissue engineering, because the scaffold made with 30 wt.% siloxane loading degrades by 48 wt.%, in 21 days. The hybrid scaffolds bearing Schiff base linkage between the polymer and siloxane, unlike the stable linkages in earlier reports, are expected to give a faster release of siloxanes and enhancement in osteogenesis. This is verified by the in vitro evaluation of the hybrid scaffolds using rabbit adipose mesenchymal stem cells, which revealed osteogenic cell-clusters on a polymer-siloxane scaffold, enhanced alkaline phosphatase activity and the expression of bone-specific genes, whereas the control scaffold without siloxane supported more of cell-proliferation than differentiation. A siloxane concentration dependent enhancement in osteogenic differentiation is also observed. - Highlights: • A hybrid scaffold bearing interpolymer-siloxane Schiff base linkage • A limiting siloxane loading of 20 wt.% into chitosan–gelatin matrix • A siloxane concentration dependent enhancement in osteogenic differentiation.

  11. Generic Delivery of Payload of Nanoparticles Intracellularly via Hybrid Polymer Capsules for Bioimaging Applications

    Science.gov (United States)

    Sami, Haider; Maparu, Auhin K.; Kumar, Ashok; Sivakumar, Sri

    2012-01-01

    Towards the goal of development of a generic nanomaterial delivery system and delivery of the ‘as prepared’ nanoparticles without ‘further surface modification’ in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM) capsules has been reported, where polystyrene sulfonate (PSS)/polyallylamine hydrochloride (PAH) polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles) in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells), without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb3+ was observed after internalization of LaF3:Tb3+(5%) nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery) without the need of individual cargo design/modification. PMID:22649489

  12. Generic delivery of payload of nanoparticles intracellularly via hybrid polymer capsules for bioimaging applications.

    Directory of Open Access Journals (Sweden)

    Haider Sami

    Full Text Available Towards the goal of development of a generic nanomaterial delivery system and delivery of the 'as prepared' nanoparticles without 'further surface modification' in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM capsules has been reported, where polystyrene sulfonate (PSS/polyallylamine hydrochloride (PAH polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells, without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb(3+ was observed after internalization of LaF(3:Tb(3+(5% nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery without the need of individual cargo design/modification.

  13. A Review on Potentiality of Nano Filler/Natural Fiber Filled Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Naheed Saba

    2014-08-01

    Full Text Available The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment.

  14. Time-Domain Ab Initio Analysis of Excitation Dynamics in a Quantum Dot/Polymer Hybrid: Atomistic Description Rationalizes Experiment.

    Science.gov (United States)

    Long, Run; Prezhdo, Oleg V

    2015-07-08

    Hybrid organic/inorganic polymer/quantum dot (QD) solar cells are an attractive alternative to the traditional cells. The original, simple models postulate that one-dimensional polymers have continuous energy levels, while zero-dimensional QDs exhibit atom-like electronic structure. A realistic, atomistic viewpoint provides an alternative description. Electronic states in polymers are molecule-like: finite in size and discrete in energy. QDs are composed of many atoms and have high, bulk-like densities of states. We employ ab initio time-domain simulation to model the experimentally observed ultrafast photoinduced dynamics in a QD/polymer hybrid and show that an atomistic description is essential for understanding the time-resolved experimental data. Both electron and hole transfers across the interface exhibit subpicosecond time scales. The interfacial processes are fast due to strong electronic donor-acceptor, as evidenced by the densities of the photoexcited states which are delocalized between the donor and the acceptor. The nonadiabatic charge-phonon coupling is also strong, especially in the polymer, resulting in rapid energy losses. The electron transfer from the polymer is notably faster than the hole transfer from the QD, due to a significantly higher density of acceptor states. The stronger molecule-like electronic and charge-phonon coupling in the polymer rationalizes why the electron-hole recombination inside the polymer is several orders of magnitude faster than in the QD. As a result, experiments exhibit multiple transfer times for the long-lived hole inside the QD, ranging from subpicoseconds to nanoseconds. In contrast, transfer of the short-lived electron inside the polymer does not occur beyond the first picosecond. The energy lost by the hole on its transit into the polymer is accommodated by polymer's high-frequency vibrations. The energy lost by the electron injected into the QD is accommodated primarily by much lower-frequency collective and

  15. Increasing the operation temperature of polymer electrolyte membranes for fuel cells: From nanocomposites to hybrids

    Science.gov (United States)

    Licoccia, Silvia; Traversa, Enrico

    Among the possible systems investigated for energy production with low environmental impact, polymeric electrolyte membrane fuel cells (PEMFCs) are very promising as electrochemical power sources for application in portable technology and electric vehicles. For practical applications, operating FCs at temperatures above 100 °C is desired, both for hydrogen and methanol fuelled cells. When hydrogen is used as fuel, an increase of the cell temperature produces enhanced CO tolerance, faster reaction kinetics, easier water management and reduced heat exchanger requirement. The use of methanol instead of hydrogen as a fuel for vehicles has several practical benefits such as easy transport and storage, but the slow oxidation kinetics of methanol needs operating direct methanol fuel cells (DMFCs) at intermediate temperatures. For this reason, new membranes are required. Our strategy to achieve the goal of operating at temperatures above 120 °C is to develop organic/inorganic hybrid membranes. The first approach was the use of nanocomposite class I hybrids where nanocrystalline ceramic oxides were added to Nafion. Nanocomposite membranes showed enhanced characteristics, hence allowing their operation up to 130 °C when the cell was fuelled with hydrogen and up to 145 °C in DMFCs, reaching power densities of 350 mW cm -2. The second approach was to prepare Class II hybrids via the formation of covalent bonds between totally aromatic polymers and inorganic clusters. The properties of such covalent hybrids can be modulated by modifying the ratio between organic and inorganic groups and the nature of the chemical components allowing to reach high and stable conductivity values up to 6.4 × 10 -2 S cm -1 at 120 °C.

  16. In vitro adhesion of staphylococci to diamond-like carbon polymer hybrids under dynamic flow conditions.

    Science.gov (United States)

    Soininen, Antti; Levon, Jaakko; Katsikogianni, Maria; Myllymaa, Katja; Lappalainen, Reijo; Konttinen, Yrjö T; Kinnari, Teemu J; Tiainen, Veli-Matti; Missirlis, Yannis

    2011-03-01

    This study compares the ability of selected materials to inhibit adhesion of two bacterial strains commonly implicated in implant-related infections. These two strains are Staphylococcus aureus (S-15981) and Staphylococcus epidermidis (ATCC 35984). In experiments we tested six different materials, three conventional implant metals: titanium, tantalum and chromium, and three diamond-like carbon (DLC) coatings: DLC, DLC-polydimethylsiloxane hybrid (DLC-PDMS-h) and DLC-polytetrafluoroethylene hybrid (DLC-PTFE-h) coatings. DLC coating represents extremely hard material whereas DLC hybrids represent novel nanocomposite coatings. The two DLC polymer hybrid films were chosen for testing due to their hardness, corrosion resistance and extremely good non-stick (hydrophobic and oleophobic) properties. Bacterial adhesion assay tests were performed under dynamic flow conditions by using parallel plate flow chambers (PPFC). The results show that adhesion of S. aureus to DLC-PTFE-h and to tantalum was significantly (P DLC-PDMS-h (0.671 ± 0.001 × 10(7)/cm(2) and 0.751 ± 0.002 × 10(7)/cm(2) vs. 1.055 ± 0.002 × 10(7)/cm(2), respectively). No significant differences were detected between other tested materials. Hence DLC-PTFE-h coating showed as low susceptibility to S. aureus adhesion as all the tested conventional implant metals. The adherence of S. epidermidis to biomaterials was not significantly (P DLC-PTFE-h films could be used as a biomaterial coating without increasing the risk of implant-related infections.

  17. Spatial modeling of the 3D morphology of hybrid polymer-ZnO solar cells, based on electron tomography data

    NARCIS (Netherlands)

    Stenzel, O.; Hassfeld, H.; Thiedmann, R.; Koster, L. J. A.; Oosterhout, S. D.; van Bavel, S. S.; Wienk, M. M.; Loos, J.; Janssen, R. A. J.; Schmidt, V.

    A spatial stochastic model is developed which describes the 3D nanomorphology of composite materials, being blends of two different (organic and inorganic) solid phases. Such materials are used, for example, in photoactive layers of hybrid polymer zinc oxide solar cells. The model is based on ideas

  18. N-type polymers as electron extraction layers in hybrid perovskite solar cells with improved ambient stability

    NARCIS (Netherlands)

    Shao, S.; Chen, Z.; Fang, H. -H.; ten Brink, G. H.; Bartesaghi, D.; Adjokatse, S.; Koster, L. J. A.; Kooi, B. J.; Facchetti, A.; Loi, M. A.

    2016-01-01

    We studied three n-type polymers of the naphthalenediimide-bithiophene family as electron extraction layers (EELs) in hybrid perovskite solar cells. The recombination mechanism in these devices is found to be heavily influenced by the EEL transport properties. The maximum efficiency of the devices

  19. Evaluation of hybrid polymers for high-precision manufacturing of 3D optical interconnects by two-photon absorption lithography

    Science.gov (United States)

    Schleunitz, A.; Klein, J. J.; Krupp, A.; Stender, B.; Houbertz, R.; Gruetzner, G.

    2017-02-01

    The fabrication of optical interconnects has been widely investigated for the generation of optical circuit boards. Twophoton absorption (TPA) lithography (or high-precision 3D printing) as an innovative production method for direct manufacture of individual 3D photonic structures gains more and more attention when optical polymers are employed. In this regard, we have evaluated novel ORMOCER-based hybrid polymers tailored for the manufacture of optical waveguides by means of high-precision 3D printing. In order to facilitate future industrial implementation, the processability was evaluated and the optical performance of embedded waveguides was assessed. The results illustrate that hybrid polymers are not only viable consumables for industrial manufacture of polymeric micro-optics using generic processes such as UV molding. They also are potential candidates to fabricate optical waveguide systems down to the chip level where TPA-based emerging manufacturing techniques are engaged. Hence, it is shown that hybrid polymers continue to meet the increasing expectations of dynamically growing markets of micro-optics and optical interconnects due to the flexibility of the employed polymer material concept.

  20. Self-Assembled Core-Shell-Type Lipid-Polymer Hybrid Nanoparticles: Intracellular Trafficking and Relevance for Oral Absorption.

    Science.gov (United States)

    Li, Qiuxia; Xia, Dengning; Tao, Jinsong; Shen, Aijun; He, Yuan; Gan, Yong; Wang, Chi

    2017-10-01

    Lipid-polymer hybrid nanoparticles (NPs) are advantageous for drug delivery. However, their intracellular trafficking mechanism and relevance for oral drug absorption are poorly understood. In this study, self-assembled core-shell lipid-polymer hybrid NPs made of poly(lactic-co-glycolic acid) (PLGA) and various lipids were developed to study their differing intracellular trafficking in intestinal epithelial cells and their relevance for oral absorption of a model drug saquinavir (SQV). Our results demonstrated that the endocytosis and exocytosis of hybrid NPs could be changed by varying the kind of lipid. A glyceride mixture (hybrid NPs-1) decreased endocytosis but increased exocytosis in Caco-2 cells, whereas the phospholipid (E200) (hybrid NPs-2) decreased endocytosis but exocytosis was unaffected as compared with PLGA nanoparticles. The transport of hybrid NPs-1 in cells involved various pathways, including caveolae/lipid raft-dependent endocytosis, and clathrin-mediated endocytosis and macropinocytosis, which was different from the other groups of NPs that involved only caveolae/lipid raft-dependent endocytosis. Compared with that of the reference formulation (nanoemulsion), the oral absorption of SQV-loaded hybrid NPs in rats was poor, probably due to the limited drug release and transcytosis of NPs across the intestinal epithelium. In conclusion, the intracellular processing of hybrid NPs in intestinal epithelia can be altered by adding lipids to the NP. However, it appears unfavorable to use PLGA-based NPs to improve oral absorption of SQV compared with nanoemulsion. Our findings will be essential in the development of polymer-based NPs for the oral delivery of drugs with the purpose of improving their oral absorption. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  1. Polymer/silica hybrid waveguide temperature sensor based on asymmetric Mach-Zehnder interferometer

    Science.gov (United States)

    Niu, Donghai; Wang, Xibin; Sun, Shiqi; Jiang, Minghui; Xu, Qiang; Wang, Fei; Wu, Yuanda; Zhang, Daming

    2018-04-01

    A highly sensitive waveguide temperature sensor based on asymmetric Mach-Zehnder interferometer was designed and experimentally demonstrated. The interferometer is based on the polymer/silica hybrid waveguide structure, and Norland Optical Adhesive 73 (NOA 73) was employed as the waveguide core to enhance the temperature sensitivity. The influence of the different length differences between the two interferometer arms on the sensitivity of the sensor was systemically studied. It is shown that the maximum temperature sensitivity of -431 pm °C-1 can be obtained in the range of 25 °C-75 °C, while the length difference is 92 μm. Moreover, the temperature sensitivity contributions from different core materials were also investigated experimentally. It is shown that the waveguide material and microstructure of the device have significant influences on the sensitivity of the waveguide temperature sensor.

  2. Hybrid Organic/Inorganic Perovskite–Polymer Nanocomposites: Toward the Enhancement of Structural and Electrical Properties

    KAUST Repository

    Privitera, Alberto

    2017-11-30

    Hybrid organic/inorganic perovskite nanoparticles (NPs) have garnered remarkable research attention because of their promising photophysical properties. New and interesting properties emerge after combining perovskite NPs with semiconducting materials. Here, we report the synthesis and investigation of a composite material obtained by mixing CH3NH3PbBr3 nanocrystals with the semiconducting polymer poly(3-hexylthiophene) (P3HT). By the combination of structural techniques and optical and magnetic spectroscopies we observed multiple effects of the perovskite NPs on the P3HT: (i) an enlargement of P3HT crystalline domains, (ii) a strong p-doping of the P3HT, and (iii) an enhancement of interchain order typical of H-aggregates. These observations open a new avenue toward innovative perovskite NP-based applications.

  3. Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids.

    Science.gov (United States)

    Dubois, Christelle; Herzog, Nicole; Rüttiger, Christian; Geißler, Andreas; Grange, Eléonor; Kunz, Ulrike; Kleebe, Hans-Joachim; Biesalski, Markus; Meckel, Tobias; Gutmann, Torsten; Gallei, Markus; Andrieu-Brunsen, Annette

    2017-01-10

    In paper-based devices, capillary fluid flow is based on length-scale selective functional control within a hierarchical porous system. The fluid flow can be tuned by altering the paper preparation process, which controls parameters such as the paper grammage. Interestingly, the fiber morphology and nanoporosity are often neglected. In this work, porous voids are incorporated into paper by the combination of dense or mesoporous ceramic silica coatings with hierarchically porous cotton linter paper. Varying the silica coating leads to significant changes in the fluid flow characteristics, up to the complete water exclusion without any further fiber surface hydrophobization, providing new approaches to control fluid flow. Additionally, functionalization with redox-responsive polymers leads to reversible, dynamic gating of fluid flow in these hybrid paper materials, demonstrating the potential of length scale specific, dynamic, and external transport control.

  4. Hybrid Organic/Inorganic Perovskite–Polymer Nanocomposites: Toward the Enhancement of Structural and Electrical Properties

    KAUST Repository

    Privitera, Alberto; Righetto, Marcello; de Bastiani, Michele; Carraro, Francesco; Rancan, Marzio; Armelao, Lidia; Granozzi, Gaetano; Bozio, Renato; Franco, Lorenzo

    2017-01-01

    Hybrid organic/inorganic perovskite nanoparticles (NPs) have garnered remarkable research attention because of their promising photophysical properties. New and interesting properties emerge after combining perovskite NPs with semiconducting materials. Here, we report the synthesis and investigation of a composite material obtained by mixing CH3NH3PbBr3 nanocrystals with the semiconducting polymer poly(3-hexylthiophene) (P3HT). By the combination of structural techniques and optical and magnetic spectroscopies we observed multiple effects of the perovskite NPs on the P3HT: (i) an enlargement of P3HT crystalline domains, (ii) a strong p-doping of the P3HT, and (iii) an enhancement of interchain order typical of H-aggregates. These observations open a new avenue toward innovative perovskite NP-based applications.

  5. Natural-Synthetic Hybrid Polymers Developed via Electrospinning: The Effect of PET in Chitosan/Starch System

    Science.gov (United States)

    Espíndola-González, Adolfo; Martínez-Hernández, Ana Laura; Fernández-Escobar, Francisco; Castaño, Victor Manuel; Brostow, Witold; Datashvili, Tea; Velasco-Santos, Carlos

    2011-01-01

    Chitosan is an amino polysaccharide found in nature, which is biodegradable, nontoxic and biocompatible. It has versatile features and can be used in a variety of applications including films, packaging, and also in medical surgery. Recently a possibility to diversify chitosan properties has emerged by combining it with synthetic materials to produce novel natural-synthetic hybrid polymers. We have studied structural and thermophysical properties of chitosan + starch + poly(ethylene terephthalate) (Ch + S + PET) fibers developed via electrospinning. Properties of these hybrids polymers are compared with extant chitosan containing hybrids synthesized by electrospinning. Molecular interactions and orientation in the fibers are analyzed by infrared and Raman spectroscopies respectively, morphology by scanning electron microscopy and thermophysical properties by thermogravimetric analysis and differential scanning calorimetry. Addition of PET to Ch + S systems results in improved thermal stability at elevated temperatures. PMID:21673930

  6. Studies on as separation behaviour of polymer blending PI/PES hybrid mixed membrane: Effect of polymer concentration and zeolite loading

    Directory of Open Access Journals (Sweden)

    Ahmad Fauzi Ismail

    2014-04-01

    Full Text Available This study is performed primarily to investigate the effect of polymer concentration of polyimide/polyethersulfone (PI/PES blending on the gas separation performance of hybrid mixed matrix membrane. In this study, PI/ (PES–zeolite 4A mixed matrix membranes were casted using dry/wet phase inversion technique. The efefct of PI/PES concentrations and zeolite loading on the dope solution were investigated for gas separation performance. The results from the Field Emission Scanning Electron Microscopy (FESEM analysis confirmed that polymer concentration and zeolite loading was affected the morphology of membrane and gas separation performance. ‘Sieve-in-a-cage’ morphology observed the poor adhesion between polymer and zeolite at higher zeolite loading. The gas separation performance of the mixed matrix membranes were relatively higher compared to that of the neat polymeric membrane.

  7. Optimization of the transport and mechanical properties of polysiloxane/polyether hybrid polymer electrolytes

    International Nuclear Information System (INIS)

    Boaretto, Nicola; Horn, Theresa; Popall, Michael; Sextl, Gerhard

    2017-01-01

    In this study, the thermo-mechanical properties of networked, polysiloxane/polyether-based, hybrid polymer electrolytes are optimized with the aim of enabling room-temperature operation in lithium metal-polymer batteries. The structural parameters of the electrolytes (polyether chain length, cross-linking and salt concentration) are varied in order to get the best tradeoff between conductivity and mechanical stability. The optimized material has a conductivity close to 1.5·10 −4 S cm −1 at room temperature and a shear storage modulus of 50 kPa up to 100 °C. The effect of TiO 2 nano-particles is also studied with the results showing an overall ambiguous effect on the materials properties. Finally, one of the materials with the highest conductivity is used as electrolyte in a Li/LiFePO 4 cell. This cell has good rate capability and cyclability due to the high conductivity of the electrolyte. However, the high conductivity is reached at expense of the mechanical stability and the resulting electrolyte proves to be too weak to work as an efficient barrier against lithium dendrite growth.

  8. Carrier transport mechanisms of hybrid ZnO nanorod-polymer LEDs

    International Nuclear Information System (INIS)

    Cho, Sungjae; Lee, Kyuseung; Son, Dongick; Oh, Youngjei; Choi, Wonkook; Angadi, Basavaraj

    2014-01-01

    A hybrid polymer-nanorod (NR) light-emitting diode (LED), consisting of a hole-conducting polymer poly (9-vinyl carbazole) (PVK) and ZnO nanorod (NR) composite, with the device structure of glass/indium-tin-oxide (ITO)/PEDOT:PSS/(PVK + ZnO nanorods)/Al is fabricated through a simple spin coating technique. TEM images shows inhomogeneous deposition and the agglomeration of ZnO NRs, which is explained through their low probability of adsorption on PVK due to two-dimensional structural property. In the current-voltage characteristics, negative differential resistance (NDR) phenomenon is observed corresponding to device structure without ZnO NRs. The carrier transport behavior in the LED device is well described by both ohmic and space-charge-limited-current (SCLC) mechanisms. Broad blue electroluminescence (EL) consisting of two sub peaks, are centered at 441 nm and the other at 495 nm, is observed, which indicates that the ZnO nanorod play a role as a recombination center for excitons. The red shift in the position of the EL compared to that photoluminescence is well explained through band offsets at the heterojunction between the PVK and ZnO NRs.

  9. MRI-guided targeting delivery of doxorubicin with reduction-responsive lipid-polymer hybrid nanoparticles

    Directory of Open Access Journals (Sweden)

    Wu B

    2017-09-01

    Full Text Available Bo Wu,1,2 Shu-Ting Lu,1 Kai Deng,2 Hui Yu,2 Can Cui,2 Yang Zhang,2 Ming Wu,2 Ren-Xi Zhuo,2 Hai-Bo Xu,1 Shi-Wen Huang2 1Department of Radiology, Zhongnan Hospital of Wuhan University, 2Key Laboratory of Biomedical Polymers, Ministry of Education, Department of Chemistry, Wuhan University, Wuhan, People’s Republic of China Abstract: In recent years, there has been increasing interest in developing a multifunctional nanoscale platform for cancer monitoring and chemotherapy. However, there is still a big challenge for current clinic contrast agents to improve their poor tumor selectivity and response. Herein, we report a new kind of Gd complex and folate-coated redox-sensitive lipid-polymer hybrid nanoparticle (Gd-FLPNP for tumor-targeted magnetic resonance imaging and therapy. Gd-FLPNPs can simultaneously accomplish diagnostic imaging, and specific targeting and controlled release of doxorubicin (DOX. They exhibit good monodispersity, excellent size stability, and a well-defined core-shell structure. Paramagnetic nanoparticles based on gadolinium-diethylenetriaminepentaacetic acid-bis-cetylamine have paramagnetic properties with an approximately two-fold enhancement in the longitudinal relaxivity compared to clinical used Magnevist. For targeted and reduction-sensitive drug delivery, Gd-FLPNPs released DOX faster and enhanced cell uptake in vitro, and exhibited better antitumor effect both in vitro and in vivo. Keywords: redox-sensitive, tumor-targeted, gadolinium, contrast agents, PLGA

  10. Self-diagnosis of structures strengthened with hybrid carbon-fiber-reinforced polymer sheets

    Science.gov (United States)

    Wu, Z. S.; Yang, C. Q.; Harada, T.; Ye, L. P.

    2005-06-01

    The correlation of mechanical and electrical properties of concrete beams strengthened with hybrid carbon-fiber-reinforced polymer (HCFRP) sheets is studied in this paper. Two types of concrete beams, with and without reinforcing bars, are strengthened with externally bonded HCFRP sheets, which have a self-structural health monitoring function due to the electrical conduction and piezoresistivity of carbon fibers. Parameters investigated include the volume fractions and types of carbon fibers. According to the investigation, it is found that the hybridization of uniaxial HCFRP sheets with several different types of carbon fibers is a viable method for enhancing the mechanical properties and obtaining a built-in damage detection function for concrete structures. The changes in electrical resistance during low strain ranges before the rupture of carbon fibers are generally smaller than 1%. Nevertheless, after the gradual ruptures of carbon fibers, the electrical resistance increases remarkably with the strain in a step-wise manner. For the specimens without reinforcing bars, the electrical behaviors are not stable, especially during the low strain ranges. However, the electrical behaviors of the specimens with reinforcing bars are relatively stable, and the whole range of self-sensing function of the HCFRP-strengthened RC structures has realized the conceptual design of the HCFRP sensing models and is confirmed by the experimental investigations. The relationships between the strain/load and the change in electrical resistance show the potential self-monitoring capacity of HCFRP reinforcements used for strengthening concrete structures.

  11. Farnesylthiosalicylic acid-loaded lipid-polyethylene glycol-polymer hybrid nanoparticles for treatment of glioblastoma.

    Science.gov (United States)

    Kaffashi, Abbas; Lüle, Sevda; Bozdağ Pehlivan, Sibel; Sarısözen, Can; Vural, İmran; Koşucu, Hüsnü; Demir, Taner; Buğdaycı, Kadir Emre; Söylemezoğlu, Figen; Karlı Oğuz, Kader; Mut, Melike

    2017-08-01

    We aimed to develop lipid-polyethylene glycol (PEG)-polymer hybrid nanoparticles, which have high affinity to tumour tissue with active ingredient, a new generation antineoplastic drug, farnesylthiosalicylic acid (FTA) for treatment of glioblastoma. Farnesylthiosalicylic acid-loaded poly(lactic-co-glycolic acid)-1,2 distearoyl-glycerol-3-phospho-ethanolamine-N [methoxy (PEG)-2000] ammonium salt (PLGA-DSPE-PEG) with or without 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) hybrid nanoparticles has been prepared and evaluated for in-vitro characterization. Cytotoxicity of FTA-loaded nanoparticles along with its efficacy on rat glioma-2 (RG2) cells was also evaluated both in vitro (in comparison with non-malignant cell line, L929) and in vivo. Scanning electron microscopy studies showed that all formulations prepared had smooth surface and spherical in shape. FTA and FTA-loaded nanoparticles have cytotoxic activity against RG2 glioma cell lines in cell culture studies, which further increases with addition of DOTAP. Magnetic resonance imaging and histopathologic evaluation on RG2 tumour cells in rat glioma model (49 female Wistar rats, 250-300 g) comparing intravenous and intratumoral injections of the drug have been performed and FTA-loaded nanoparticles reduced tumour size significantly in in-vivo studies, with higher efficiency of intratumoral administration than intravenous route. Farnesylthiosalicylic acid-loaded PLGA-DSPE-PEG-DOTAP hybrid nanoparticles are proven to be effective against glioblastoma in both in-vitro and in-vivo experiments. © 2017 Royal Pharmaceutical Society.

  12. Magnetic properties of the magnetic hybrid membranes based on various polymer matrices and inorganic fillers

    International Nuclear Information System (INIS)

    Rybak, Aleksandra; Kaszuwara, Waldemar

    2015-01-01

    Magnetic hybrid membranes based on ethylcellulose (EC), poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and various magnetic praseodymium and neodymium powder microparticles as fillers were obtained. Permeability, diffusion and sorption coefficients of O 2 , N 2 and synthetic air components were estimated for homogeneous and heterogeneous membranes using the Time Lag method based on constant pressure permeation technique. The microstructure studies and the phase analysis of magnetic membranes were also performed using SEM and XRD. The influence of magnetic parameters, like coercivity, remanence and saturation magnetization of created membranes on the gas transport properties was studied. The results showed that their coercivity depended on composition and microstructure of the magnetic powder. On the other hand, remanence and saturation magnetization increased with the increase of the powder addition in the membrane. It was found that the magnetic membrane's gas transport properties were improved with the increase of membrane's remanence, saturation magnetization and magnetic particle filling. The decrease in powder particle size and associated increase of the membrane's coercivity also positively influenced the gas transport and separation properties of investigated membranes. It was observed that the magnetic ethylcellulose and poly(2,6-dimethyl-1,4-phenylene oxide) membranes had higher gas permeability, while their permselectivity and solubility coefficient values were rather maintained or slightly increased. The results also showed that the magnetic powder content enhanced significantly gas diffusivity in EC and PPO membranes. It was also analyzed the dependence of the drift coefficient w on the magnetic parameters of investigated membranes. The correlation between the membrane selectivity, permeability and magnetic properties with their XRD characteristics was stated. - Highlights: • Membrane's production consisting of EC or PPO polymers and

  13. Magnetic properties of the magnetic hybrid membranes based on various polymer matrices and inorganic fillers

    Energy Technology Data Exchange (ETDEWEB)

    Rybak, Aleksandra, E-mail: Aleksandra.Rybak@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Kaszuwara, Waldemar [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warszawa (Poland)

    2015-11-05

    polymers and various magnetic powders. • Polymer hybrid membranes with the magnetic powder for air separation. • Experimental studies of transport processes through magnetic hybrid membranes. • Correlation between gas transport and magnetic properties with XRD characteristics. • Positive effect of the remanence growth on separation properties of membranes.

  14. Helix-sense-selective co-precipitation for preparing optically active helical polymer nanoparticles/graphene oxide hybrid nanocomposites.

    Science.gov (United States)

    Huang, Huajun; Li, Weifei; Shi, Yan; Deng, Jianping

    2017-05-25

    Constructing optically active helical polymer based nanomaterials without using expensive and limited chirally helical polymers has become an extremely attractive research topic in both chemical and materials science. In this study, we prepared a series of optically active helical polymer nanoparticles/graphene oxide (OAHPNs/GO) hybrid nanocomposites through an unprecedented strategy-the co-precipitation of optically inactive helical polymers and chirally modified GO. This approach is named helix-sense-selective co-precipitation (HSSCP), in which the chirally modified GO acted as a chiral source for inducing and further stabilizing the predominantly one-handed helicity in the optically inactive helical polymers. SEM and TEM images show quite similar morphologies of all the obtained OAHPNs/GO nanocomposites; specifically, the chirally modified GO sheets were uniformly decorated with spherical polymer nanoparticles. Circular dichroism (CD) and UV-vis absorption spectra confirmed the preferentially induced helicity in the helical polymers and the optical activity of the nanocomposites. The established HSSCP strategy is thus proven to be widely applicable and is expected to produce numerous functional OAHPNs/GO nanocomposites and even the analogues.

  15. Polymer-lipid-PEG hybrid nanoparticles as photosensitizer carrier for photodynamic therapy.

    Science.gov (United States)

    Pramual, Sasivimon; Lirdprapamongkol, Kriengsak; Svasti, Jisnuson; Bergkvist, Magnus; Jouan-Hureaux, Valérie; Arnoux, Philippe; Frochot, Céline; Barberi-Heyob, Muriel; Niamsiri, Nuttawee

    2017-08-01

    Polymer-lipid-PEG hybrid nanoparticles were investigated as carriers for the photosensitizer (PS), 5,10,15,20-Tetrakis(4-hydroxy-phenyl)-21H,23H-porphine (pTHPP) for use in photodynamic therapy (PDT). A self-assembled nanoprecipitation technique was used for preparing two types of core polymers poly(d,l-lactide-co-glycolide) (PLGA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with lipid-PEG as stabilizer. The resulting nanoparticles had an average particle size of 88.5±3.4nm for PLGA and 215.0±6.3nm for PHBV. Both nanoparticles exhibited a core-shell structure under TEM with high zeta potential and loading efficiency. X-ray powder diffraction analysis showed that the encapsulated pTHPP molecules in polymeric nanoparticles no longer had peaks of free pTHPP in the crystalline state. The pTHPP molecules encapsulated inside the polymeric core demonstrated improved photophysical properties in terms of singlet oxygen generation and cellular uptake rate in a FTC-133 human thyroid carcinoma cell line, compared to non-encapsulated pTHPP. The pTHPP-loaded polymer-lipid-PEG nanoparticles showed better in vitro phototoxicity compared to free pTHPP, in both time- and concentration-dependent manners. Overall, this study provides detailed analysis of the photophysical properties of pTHPP molecules when entrapped within either PLGA or PHBV nanoparticle cores, and demonstrates the effectiveness of these systems for delivery of photosensitizers. The two polymeric systems may have different potential benefits, when used with cancer cells. For instance, the pTHPP-loaded PLGA system requires only a short time to show a PDT effect and may be suitable for topical PDT, while the delayed photo-induced cytotoxic effect of the pTHPP-loaded PHBV system may be more suitable for cancer solid tumors. Hence, both pTHPP-encapsulated polymer-lipid-PEG nanoparticles can be considered promising delivery systems for PDT cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Hybrid thin-film solar cells comprising mesoporous titanium dioxide and conjugated polymers; Hybride Duennschicht-Solarzellen aus mesoporoesem Titandioxid und konjugierten Polymeren

    Energy Technology Data Exchange (ETDEWEB)

    Schattauer, Sylvia

    2010-12-01

    The main objective of this thesis is to study the active components and their interactions in so called organic hybrid solar cells. These consist of a thin inorganic titanium dioxide layer, combined with a polymer layer. In general, the efficiency of these hybrid solar cells is determined by the light absorption in the donor polymer, the dissociation of excitons at the heterojunction between TiO{sub 2} and polymer, as well as the generation and extraction of free charge carriers. To optimize the solar cells, the physical interactions between the materials are modified and the influences of various preparation parameters are systematically investigated. Among others, important findings regarding the optimal use of materials and preparation conditions as well as detailed investigations of fundamental factors such as film morphology and polymer infiltration are presented in more detail. First, a variety of titanium dioxide layer were produced, from which a selection for use in hybrid solar cells was made. The obtained films show differences in surface structure, film morphology and crystallinity, depending on the way how the TiO{sub 2} layer has been prepared. All these properties of the TiO{sub 2} films may strongly affect the performance of the hybrid solar cells, by influencing e.g. the exciton diffusion length, the efficiency of exciton dissociation at the hybrid interface, and the carrier transport properties. Detailed investigations were made for mesoporous TiO{sub 2} layer following a new nanoparticle synthesis route, which allows to produce crystalline particles during the synthesis. As donor component, conjugated polymers, either derivatives of cyclohexylamino-poly(p-phenylene vinylene) (PPV) or a thiophene are used. The preparation routine also includes a thermal treatment of the TiO{sub 2} layers, revealing a temperature-dependent change in morphology, but not of the crystal structure. The effects on the solar cell properties have been documented and

  17. Charge separation dynamics in a narrow band gap polymer-PbS nanocrystal blend for efficient hybrid solar cells

    NARCIS (Netherlands)

    Piliego, Claudia; Manca, Marianna; Kroon, Renee; Yarema, Maksym; Szendrei, Krisztina; Andersson, Mats R.; Heiss, Wolfgang; Loi, Maria A.

    2012-01-01

    We have demonstrated efficient hybrid solar cells based on lead sulfide (PbS) nanocrystals and a narrow band gap polymer, poly[{2,5-bis(2-hexyldecyl)-2,3,5,6-tetrahydro-3,6-dioxopyrrolo[3,4-c]pyrrole-1,4-diyl}-alt-{[2,2'-(1,4-phenylene)bis-thiophene]-5,5'-diyl}], (PDPPTPT). An opportune mixing of

  18. Dry powder inhaler formulation of lipid-polymer hybrid nanoparticles via electrostatically-driven nanoparticle assembly onto microscale carrier particles.

    Science.gov (United States)

    Yang, Yue; Cheow, Wean Sin; Hadinoto, Kunn

    2012-09-15

    Lipid-polymer hybrid nanoparticles have emerged as promising nanoscale carriers of therapeutics as they combine the attractive characteristics of liposomes and polymers. Herein we develop dry powder inhaler (DPI) formulation of hybrid nanoparticles composed of poly(lactic-co-glycolic acid) and soybean lecithin as the polymer and lipid constituents, respectively. The hybrid nanoparticles are transformed into inhalable microscale nanocomposite structures by a novel technique based on electrostatically-driven adsorption of nanoparticles onto polysaccharide carrier particles, which eliminates the drawbacks of conventional techniques based on controlled drying (e.g. nanoparticle-specific formulation, low yield). First, we engineer polysaccharide carrier particles made up of chitosan cross-linked with tripolyphosphate and dextran sulphate to exhibit the desired aerosolization characteristics and physical robustness. Second, we investigate the effects of nanoparticle to carrier mass ratio and salt inclusion on the adsorption efficiency, in terms of the nanoparticle loading and yield, from which the optimal formulation is determined. Desorption of the nanoparticles from the carrier particles in phosphate buffer saline is also examined. Lastly, we characterize aerosolization efficiency of the nanocomposite product in vitro, where the emitted dose and respirable fraction are found to be comparable to the values of conventional DPI formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Understanding interpenetrating-polymer-network-like porous nitrile butadiene rubber hybrids by their long-period miscibility

    International Nuclear Information System (INIS)

    Zhang, Jihua; Wang, Lifeng; Zhao, Yunfeng

    2013-01-01

    Highlights: • Hydrogen bonds are introduced into NBR to develop its IPN-like porous hybrids. • NBR is partly miscible with AO-60. • AO-60 possesses the viscoelastic behavior resembling that of polymers. • Phase separation aggravates and AO-60 crystallizes in the durations. • The porous hybrids may have potential damping applications. - Abstract: In this article, tetrakis [methylene-3-(3, 5-di-tert-butyl-4-hydroxy phenyl) propionyloxy] methane (AO-60) with hydrogen bonds was designed to interpenetrate into the chemical crosslinking bonds of nitrile butadiene rubber (NBR) and then porous materials were prepared. Scanning electron microscopy (SEM), atomic force microscopy (AFM) images and dynamic mechanical analyses (DMA) demonstrate that NBR is partly miscible with AO-60 which induces the micro-pores and interpenetrating-polymer-network (IPN)-like phase morphology in the hybrids. The wide double tan δ peak in DMA curve displays that AO-60 possesses similar viscoelastic behaviors to polymers which come from supramolecular interactions between polar groups of NBR chains and hydroxyl (OH) groups of AO-60. To further understand the supramolecular abilities of AO-60 in the rubber, the long-period observations for their miscibility are conducted. With the increase of durations, the hydrogen bond network from AO-60 is weakened. The phase separation between AO-60 and NBR is aggravated and even extremely few AO-60 crystallizes which develops multi-scale porous morphology in the hybrids. It is believed that these findings can serve as a guide for the designs of the IPN-like hybrids with small molecule substances and their applications of damping materials

  20. Effect of the polymer emission on the electroluminescence characteristics of n-ZnO nanorods/p-polymer hybrid light emitting diode

    Science.gov (United States)

    Zaman, S.; Zainelabdin, A.; Amin, G.; Nur, O.; Willander, M.

    2011-09-01

    Hybrid light emitting diodes (LEDs) based on zinc oxide (ZnO) nanorods and polymers (single and blended) were fabricated and characterized. The ZnO nanorods were grown by the chemical bath deposition method at 50°C. Three different LEDs, with blue emitting, orange-red emitting or their blended polymer together with ZnO nanorods, were fabricated and studied. The current-voltage characteristics show good diode behavior with an ideality factor in the range of 2.1 to 2.27 for all three devices. The electroluminescence spectrum (EL) of the blended device has an emission range from 450 nm to 750 nm, due to the intermixing of the blue emission generated by poly(9,9-dioctylfluorene) denoted as PFO with orange-red emission produced by poly(2-methoxy-5(20-ethyl-hexyloxy)-1,4-phenylenevinylene) 1,4-phenylenevinylene) symbolized as MEH PPV combined with the deep-band emission (DBE) of the ZnO nanorods, i.e. it covers the whole visible region and is manifested as white light. The CIE color coordinates showed bluish, orange-red and white emission from the PFO, MEH PPV and blended LEDs with ZnO nanorods, respectively. These results indicate that the choice of the polymer with proper concentration is critical to the emitted color in ZnO nanorods/p-organic polymer LEDs and careful design should be considered to obtain intrinsic white light sources.

  1. Design of nanocarriers for nanoscale drug delivery to enhance cancer treatment using hybrid polymer and lipid building blocks.

    Science.gov (United States)

    Zhang, Rui Xue; Ahmed, Taksim; Li, Lily Yi; Li, Jason; Abbasi, Azhar Z; Wu, Xiao Yu

    2017-01-26

    Polymer-lipid hybrid nanoparticles (PLN) are an emerging nanocarrier platform made from building blocks of polymers and lipids. PLN integrate the advantages of biomimetic lipid-based nanoparticles (i.e. solid lipid nanoparticles and liposomes) and biocompatible polymeric nanoparticles. PLN are constructed from diverse polymers and lipids and their numerous combinations, which imparts PLN with great versatility for delivering drugs of various properties to their nanoscale targets. PLN can be classified into two types based on their hybrid nanoscopic structure and assembly methods: Type-I monolithic matrix and Type-II core-shell systems. This article reviews the history of PLN development, types of PLN, lipid and polymer candidates, fabrication methods, and unique properties of PLN. The applications of PLN in delivery of therapeutic or imaging agents alone or in combination for cancer treatment are summarized and illustrated with examples. Important considerations for the rational design of PLN for advanced nanoscale drug delivery are discussed, including selection of excipients, synthesis processes governing formulation parameters, optimization of nanoparticle properties, improvement of particle surface functionality to overcome macroscopic, microscopic and cellular biological barriers. Future directions and potential clinical translation of PLN are also suggested.

  2. Fabrication of 2D protein microstructures and 3D polymer-protein hybrid microstructures by two-photon polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, Sascha [Lehrstuhl fuer Lasertechnik, RWTH Aachen, Steinbachstrasse 15, Aachen (Germany); Hoch, Eva; Tovar, Guenter E M [Institut fuer Grenzflaechenverfahrenstechnik, Universitaet Stuttgart, Nobelstrasse 12, Stuttgart (Germany); Borchers, Kirsten [Fraunhofer-Institut fuer Grenzflaechen- und Bioverfahrenstechnik, Nobelstrasse 12, Stuttgart (Germany); Meyer, Wolfdietrich; Krueger, Hartmut [Fraunhofer-Institut fuer Angewandte Polymerforschung, Geiselbergstrasse 69, Potsdam (Germany); Gillner, Arnold, E-mail: sascha.engelhardt@ilt.fraunhofer.de [Fraunhofer-Institut fuer Lasertechnik, Steinbachstrasse 15, Aachen (Germany)

    2011-06-15

    Two-photon polymerization (TPP) offers the possibility of creating artificial cell scaffolds composed of micro- and nanostructures with spatial resolutions of less than 1 {mu}m. For use in tissue engineering, the identification of a TPP-processable polymer that provides biocompatibility, biofunctionality and appropriate mechanical properties is a difficult task. ECM proteins such as collagen or fibronectin, which could mimic native tissues best, often lack the mechanical stability. Hence, by generating polymer-protein hybrid structures, the beneficial properties of proteins can be combined with the advantageous characteristics of polymers, such as sufficient mechanical stability. This study describes three steps toward facilitated application of TPP for biomaterial generation. (1) The efficiency of a low-cost ps-laser source is compared to a fs-laser source by testing several materials. A novel photoinitiator for polymerization with a ps-laser source is synthesized and proved to enable increased fabrication throughput. (2) The fabrication of 3D-microstructures with both systems and the fabrication of polymer-protein hybrid structures are demonstrated. (3) The tissue engineering capabilities of TPP are demonstrated by creating cross-linked gelatin microstructures, which clearly forced porcine chondrocytes to adapt their cell morphology.

  3. The modification of nanocomposite hybrid polymer surfaces by exposure to oxygen containing plasmas

    Science.gov (United States)

    Figueiredo, Ashley; Zimmermann, Katherine; Augustine, Brian; Hughes, Chris; Chusuei, Charles

    2006-11-01

    The wetting properties of the surfaces of the nanocomposite hybrid polymer poly[(propylmethacryl-heptaisobutyl- polyhedral oligomeric silsequioxane)-co-(methylmethacrylate)] (POSS-PMMA)has been studied before and after exposure to plasmas containing oxygen. The contact angle of water droplets on the surface showed a substantial decrease after plasma exposure indicating an increase in the hydrophilicity of the surface. A model was developed in which the plasma preferentially removed organic material including both the PMMA backbone and isobutyl groups from the corners of the POSS cages leaving behind a surface characterized by the silicon oxide-like POSS material. Measurements of surface concentrations of oxygen, silicon, and carbon by x-ray photoelectron spectroscopy (XPS) showed an increase in the amount of oxygen and silicon compared to carbon and the appropriate chemical shifts were observed in the XPS data to support the model of Si-O enrichment on the surface. Variable angle spectroscopic ellipsometry (VASE) and atomic force microscopy (AFM) measurements also supported the model and these results will be presented.

  4. Refractive Index Tuning of Hybrid Materials for Highly Transmissive Luminescent Lanthanide Particle-Polymer Composites.

    Science.gov (United States)

    Kim, Paul; Li, Cheng; Riman, Richard E; Watkins, James

    2018-03-14

    High-refractive-index ZrO 2 nanoparticles were used to tailor the refractive index of a polymer matrix to match that of luminescent lanthanide-ion-doped (La 0.92 Yb 0.075 Er 0.005 F 3 ) light-emitting particles, thereby reducing scattering losses to yield highly transparent emissive composites. Photopolymerization of blends of an amine-modified poly(ether acrylate) oligomer and tailored quantities of ZrO 2 nanoparticles yielded optically transparent composites with tailored refractive indices between 1.49 and 1.69. By matching the refractive index of the matrix to that of La 0.92 Yb 0.075 Er 0.005 F 3 , composites with high transmittance (>85%) and low haze from the visible to infrared regions, bright 1530 nm optical emissions were achieved at solids loadings of La 0.92 Yb 0.075 Er 0.005 F 3 , ranging from 5 to 30 vol %. These optical results suggest that a hybrid matrix approach is a versatile strategy for the fabrication of functional luminescent optical composites of high transparency.

  5. Nafion-TiO{sub 2} hybrid membranes for medium temperature polymer electrolyte fuel cells (PEFCs)

    Energy Technology Data Exchange (ETDEWEB)

    Sacca, A.; Carbone, A.; Passalacqua, E. [CNR-ITAE, Via Salita S. Lucia Sopra Contesse, 98126 Messina (Italy); D' Epifanio, A.; Licoccia, S.; Traversa, E. [Department of Chemical Science and Technology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Sala, E.; Traini, F.; Ornelas, R. [Nuvera Fuel Cells, Via Bistolfi 35, 20134 Milan (Italy)

    2005-12-01

    A nanocomposite re-cast Nafion hybrid membrane containing titanium oxide calcined at T=400{sup o}C as an inorganic filler was developed in order to work at medium temperature in polymer electrolyte fuel cells (PEFCs) maintaining a suitable membrane hydration under fuel cell operative critical conditions. Nanometre TiO{sub 2} powder was synthesized via a sol-gel procedure by a rapid hydrolysis of Ti(OiPr){sub 4}. The membrane was prepared by mixing a Nafion-dimethylacetammide (DMAc) dispersion with a 3wt% of TiO{sub 2} powder and casting the mixture by Doctor Blade technique. The resulting film was characterised in terms of water uptake and ion exchange capacity (IEC). The membrane was tested in a single cell from 80 to 130{sup o}C in humidified H{sub 2}/air. The obtained results were compared with the commercial Nafion115 and a home-made recast Nafion membrane. Power density values of 0.514 and 0.256Wcm{sup -2} at 0.56V were obtained at 110 and 130{sup o}C, respectively, for the composite Nafion-Titania membrane. Preliminary tests carried out using steam reforming (SR) synthetic fuel at about 110{sup o}C have highlighted the benefit of the inorganic filler introduction when PEFC operates at medium temperature and with processed hydrogen. (author)

  6. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    Directory of Open Access Journals (Sweden)

    Minh-Tai Le

    2015-08-01

    Full Text Available In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA and thermogravimetric analysis (TGA are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg, as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs.

  7. Photovoltaic and Electroluminescence Characters in Hybrid ZnO and Conjugated Polymer Bulk Heterojunction Devices

    Institute of Scientific and Technical Information of China (English)

    LIU Jun-Peng; QU Sheng-Chun; XU Ying; CHEN Yong-Hai; ZENG Xiang-Bo; WANG Zhi-Jie; ZHOU Hui-Ying; WANG Zhan-Guo

    2007-01-01

    We report electroluminescence in hybrid ZnO and conjugated polymer poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) bulk heterojunction photovoltaic cells. Photoluminescence quenching experimental results indicate that the ultrafast photoinduced electron transfer occurs from MDMO-PPV to ZnO under illumination. The ultrafast photoinduced electron transfer effect is induced because ZnO has an electron affinity about 1.2 eV greater than that of MDMO-PPV. Electron 'back transfer' can occur if the interfacial barrier between ZnO and MDMO-PPV can be overcome by applying a substantial electric field. Therefore, electroluminescence action due to the fact that the back transfer effect can be observed in the ZnO: MDMO-PPV devices since a forward bias is applied. The photovoltaic and electroluminescence actions in the same ZnO: MDMO-PPV device can be induced by different injection ways: photoinjection and electrical injection. The devices are expected to provide an opportunity for dual functionality devices with photovoltaic effect and electroluminescence character.

  8. Preparation and toxicological assessment of functionalized carbon nanotube-polymer hybrids.

    Directory of Open Access Journals (Sweden)

    Nikos D Koromilas

    Full Text Available Novel Carbon Nanotube-Polymer Hybrids were synthesized as potential materials for the development of membranes for water treatment applications in the field of Membrane Bioreactors (MBRs. Due to the toxicological concerns regarding the use of nanomaterials in water treatment as well as the rising demand for safe drinking water to protect public health, we studied the functionalization of MWCNTs and Thin-MWCNTs as to control their properties and increase their ability of embedment into porous anisotropic polymeric membranes. Following the growth of the hydrophilic monomer on the surface of the properly functionalized CNTs, that act as initiator for the controlled radical polymerization (ATRP of sodium styrene sulfonate (SSNa, the antimicrobial quaternized phosphonium and ammonium salts were attached on CNTs-g-PSSNa through non-covalent bonding. In another approach the covalent attachment of quaternized ammonium polymeric moieties of acrylic acid-vinyl benzyl chloride copolymers with N,N-dimethylhexadecylamine (P(AA12-co-VBCHAM on functionalized CNTs has also been attempted. Finally, the toxicological assessment in terms of cell viability and cell morphological changes revealed that surface characteristics play a major role in the biological response of functionalized CNTs.

  9. Adhesion of staphylococcal and Caco-2 cells on diamond-like carbon polymer hybrid coating.

    Science.gov (United States)

    Kinnari, Teemu J; Soininen, Antti; Esteban, Jaime; Zamora, Nieves; Alakoski, Esa; Kouri, Vesa-Petteri; Lappalainen, Reijo; Konttinen, Yrjö T; Gomez-Barrena, Enrique; Tiainen, Veli-Matti

    2008-09-01

    Staphylococci cause the majority of the nosocomial implant-related infections initiated by adhesion of planktonic bacteria to the implant surface. It was hypothesized that plasma accelerating filtered pulsed arc discharge method enables combination of the advantageous properties of diamond with the antisoiling properties of polymers. Diamond-like carbon polytetrafluoroethylene hybrid (DLC-PTFE-h) coating was produced. The adhesion of S. aureus ATCC 25923 (10(8) colony-forming units/mL) to surfaces diminished from 2.32%, 2.35%, and 2.57% of high quality DLC, titanium, and oxidized silicon, respectively, to 1.93% of DLC-PTFE-h. For S. epidermidis ATCC 35984 the corresponding figures were 3.90%, 3.32%, 3.47%, and 2.57%. Differences in bacterial adhesion between recombinant DLC-PTFE-h and other materials were statistically significant (p DLC-PTFE-h as to DLC, titanium, or silicon, which were all in the MTT test found to be cytocompatible. DLC-PTFE-h coating can be used to modify the surface properties of any surgical implants and is an unfavorable substrate for staphylococcal cells, but compatible with human Caco-2 cells. DLC-PTFE-h coating may help in the combat against Staphylococcus-related implant infections which usually require both antibiotics and surgical removal of the implant for cure.

  10. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    Science.gov (United States)

    Le, Minh-Tai; Huang, Shyh-Chour

    2015-01-01

    In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs) by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg), as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs. PMID:28793521

  11. Mechanistic profiling of the siRNA delivery dynamics of lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Colombo, Stefano; Cun, Dongmei; Remaut, Katrien; Bunker, Matt; Zhang, Jianxin; Martin-Bertelsen, Birte; Yaghmur, Anan; Braeckmans, Kevin; Nielsen, Hanne M; Foged, Camilla

    2015-03-10

    Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(DL-lactic-co-glycolic acid) (PLGA) nanocarriers modified with the cationic lipid dioleoyltrimethyl-ammoniumpropane (DOTAP). A library of siRNA-loaded LPNs was prepared by systematically varying the nitrogen-to-phosphate (N/P) ratio. Atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM) combined with small angle X-ray scattering (SAXS) and confocal laser scanning microscopy (CLSM) studies suggested that the siRNA-loaded LPNs are characterized by a core-shell structure consisting of a PLGA matrix core coated with lamellar DOTAP structures with siRNA localized both in the core and in the shell. Release studies in buffer and serum-containing medium combined with in vitro gene silencing and quantification of intracellular siRNA suggested that this self-assembling core-shell structure influences the siRNA release kinetics and the delivery dynamics. A main delivery mechanism appears to be mediated via the release of transfection-competent siRNA-DOTAP lipoplexes from the LPNs. Based on these results, we suggest a model for the nanostructural characteristics of the LPNs, in which the siRNA is organized in lamellar superficial assemblies and/or as complexes entrapped in the polymeric matrix. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Folate-containing reduction-sensitive lipid-polymer hybrid nanoparticles for targeted delivery of doxorubicin.

    Science.gov (United States)

    Wu, Bo; Yu, Ping; Cui, Can; Wu, Ming; Zhang, Yang; Liu, Lei; Wang, Cai-Xia; Zhuo, Ren-Xi; Huang, Shi-Wen

    2015-04-01

    The development and evaluation of folate-targeted and reduction-triggered biodegradable nanoparticles are introduced to the research on targeted delivery of doxorubicin (DOX). This type of folate-targeted lipid-polymer hybrid nanoparticles (FLPNPs) is comprised of a poly(D,L-lactide-co-glycolide) (PLGA) core, a soybean lecithin monolayer, a monomethoxy-poly(ethylene glycol)-S-S-hexadecyl (mPEG-S-S-C16) reduction-sensitive shell, and a folic acid-targeted ligand. FLPNPs exhibited high size stability but fast disassembly in a simulated cancer cell reductive environment. The experiments on the release process in vitro revealed that as a reduction-sensitive drug delivery system, FLPNPs released DOX faster in the presence of 10 mM dithiothreitol (DTT). Results from flow cytometry, confocal image and in vitro cytotoxicity assays revealed that FLPNPs further enhanced cell uptake and generated higher cytotoxicity against human epidermoid carcinoma in the oral cavity than non-targeted redox-sensitive and targeted redox-insensitive controls. Furthermore, in vivo animal experiments demonstrated that systemic administration of DOX-loaded FLPNPs remarkably reduced tumor growth. Experiments on biodistribution of DOX-loaded FLPNPs showed that an increasing amount of DOX accumulated in the tumor. Therefore, FLPNPs formulations have proved to be a stable, controllable and targeted anticancer drug delivery system.

  13. MRI-guided targeting delivery of doxorubicin with reduction-responsive lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Wu, Bo; Lu, Shu-Ting; Deng, Kai; Yu, Hui; Cui, Can; Zhang, Yang; Wu, Ming; Zhuo, Ren-Xi; Xu, Hai-Bo; Huang, Shi-Wen

    2017-01-01

    In recent years, there has been increasing interest in developing a multifunctional nanoscale platform for cancer monitoring and chemotherapy. However, there is still a big challenge for current clinic contrast agents to improve their poor tumor selectivity and response. Herein, we report a new kind of Gd complex and folate-coated redox-sensitive lipid-polymer hybrid nanoparticle (Gd-FLPNP) for tumor-targeted magnetic resonance imaging and therapy. Gd-FLPNPs can simultaneously accomplish diagnostic imaging, and specific targeting and controlled release of doxorubicin (DOX). They exhibit good monodispersity, excellent size stability, and a well-defined core-shell structure. Paramagnetic nanoparticles based on gadolinium-diethylenetriaminepentaacetic acid-bis-cetylamine have paramagnetic properties with an approximately two-fold enhancement in the longitudinal relaxivity compared to clinical used Magnevist. For targeted and reduction-sensitive drug delivery, Gd-FLPNPs released DOX faster and enhanced cell uptake in vitro, and exhibited better antitumor effect both in vitro and in vivo.

  14. PEG-detachable lipid-polymer hybrid nanoparticle for delivery of chemotherapy drugs to cancer cells.

    Science.gov (United States)

    Du, Jiang-bo; Song, Yan-feng; Ye, Wei-liang; Cheng, Ying; Cui, Han; Liu, Dao-zhou; Liu, Miao; Zhang, Bang-le; Zhou, Si-yuan

    2014-08-01

    The experiment aimed to increase the drug-delivery efficiency of poly-lactic-co-glycolic acid (PLGA) nanoparticles. Lipid-polymer hybrid nanoparticles (LPNs-1) were prepared using PLGA as a hydrophobic core and FA-PEG-hyd-DSPE as an amphiphilic shell. Uniform and spherical nanoparticles with an average size of 185 nm were obtained using the emulsification solvent evaporation method. The results indicated that LPNs-1 showed higher drug loading compared with naked PLGA nanoparticles (NNPs). Drug release from LPNs-1 was faster in an acidic environment than in a neutral environment. LPNs-1 showed higher cytotoxicity on KB cells, A549 cells, MDA-MB-231 cells, and MDA-MB-231/ADR cells compared with free doxorubicin (DOX) and NNPs. The results also showed that, compared with free DOX and NNPs, LPNs-1 delivered more DOX to the nuclear of KB cells and MDA-MB-231/ADR cells. LPNs-1 induced apoptosis in KB cells and MDA-MB-231/ADR cells in a dose-dependent manner. The above data indicated that DOX-loaded LPNs-1 could kill not only normal tumor cells but also drug-resistant tumor cells. These results indicated that modification of PLGA nanoparticles with FA-PEG-hyd-DSPE could considerably increase the drug-delivery efficiency and LPNs-1 had potential in the delivery of chemotherapeutic agents in the treatment of cancer.

  15. A facile synthesis of C{sub 60}-organosilicon hybrid polymers: Considering their tunable optical properties for spin-on-silicon hardmask materials

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin-Kyu; Dao, Tung Duy; Kim, Ye-Seul; Jeong, Hyun-Dam, E-mail: hdjeong@chonnam.ac.kr

    2016-09-15

    Organic-inorganic hybrid materials with high refractive index have attracted considerable attention for many optoelectronic applications, including spin-on-type hardmask for ArF lithography (193 nm). In this study, we demonstrate the synthesis of a C{sub 60}-embedded organosilicon hybrid polymer, C{sub 60}-embedded poly-xylene-hexamethyltrisiloxane hybrid (C{sub 60}-PXS), of tunable optical properties. C{sub 60} was covalently bonded to the PXS backbone through Pt-catalyzed hydrosilylation, in which the PXS was formed possibly by unexpected transition metal-catalyzed benzylic C−H silylation and oxygenation of the o-xylene. The C{sub 60}-PXS thin films fabricated using a spin-coating method showed much higher refractive index by 5–22% according to the curing temperatures, than the PXS thin films containing no C{sub 60}. In particular, the C{sub 60}-PXS thin film cured at 350 °C showed the refractive index (n) and extinction coefficient (k) at 193 nm to be 1.61 and 0.29 that are very close to the optimum values for the Si-hardmask. This implies the high applicability of the C{sub 60}-embedded organosilicon hybrid polymer, C{sub 60}-PXS, for the spin-on Si-hardmask in ArF lithography. - Highlights: • A facile synthetic route for C{sub 60}-embedded organosilicon hybrid polymer was presented. • The hybrid polymer showed much higher refractive index than the polymer without C{sub 60}. • The hybrid polymer is highly applicable for Si-hardmask in terms of optical properties. • It is believed that the properties of the hybrid polymer can be further optimized.

  16. Organic-inorganic hybrid polymer electrolytes based on polyether diamine, alkoxysilane, and trichlorotriazine: Synthesis, characterization, and electrochemical applications

    Science.gov (United States)

    Saikia, Diganta; Wu, Cheng-Gang; Fang, Jason; Tsai, Li-Duan; Kao, Hsien-Ming

    2014-12-01

    A new type of highly conductive organic-inorganic hybrid polymer electrolytes has been synthesized by the reaction of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), 2,4,6-trichloro-1,3,5-triazine and alkoxysilane precursor 3-(glycidyloxypropyl)trimethoxysilane, followed by doping of LiClO4. The 13C and 29Si solid-sate NMR results confirm the successful synthesis of the organic-inorganic hybrid structure. The solid hybrid electrolyte thus obtained exhibits a maximum ionic conductivity of 1.6 × 10-4 S cm-1 at 30 °C, which is the highest among the organic-inorganic hybrid electrolytes. The hybrid electrolytes are electrochemically stable up to 4.2 V. The prototype electrochromic device with such a solid hybrid electrolyte demonstrates a good coloration efficiency value of 183 cm2 C-1 with a cycle life over 200 cycles. For the lithium-ion battery test, the salt free solid hybrid membrane is swelled with a LiPF6-containing electrolyte solution to reach an acceptable ionic conductivity value of 6.5 × 10-3 S cm-1 at 30 °C. The battery cell carries an initial discharge capacity of 100 mAh g-1 at 0.2C-rate and a coulombic efficiency of about 95% up to 30 cycles without the sign of cell failure. The present organic-inorganic hybrid electrolytes hold promise for applications in electrochromic devices and lithium ion batteries.

  17. Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

    Directory of Open Access Journals (Sweden)

    Sanju Gupta

    2015-10-01

    Full Text Available Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO1, (PPy/ErGO1, (PAni/GO1 and (PPy/GO1. The rationale design is to create thin films that possess interconnected graphene nanosheets (GNS with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, Cs, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent Cs of ≥350 F g−1 as compared with constituents (∼70 F g−1 at discharge current density of 0.3 A g−1 that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting and conducting polymers (semiconducting backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to determine electrochemical (reactivity of surface ion

  18. Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sanju, E-mail: sanju.gupta@wku.edu; Price, Carson [Department of Physics and Astronomy, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY 42101-3576 (United States)

    2015-10-15

    Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL) assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO){sub 1}, (PPy/ErGO){sub 1}, (PAni/GO){sub 1} and (PPy/GO){sub 1}. The rationale design is to create thin films that possess interconnected graphene nanosheets (GNS) with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, C{sub s}, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent C{sub s} of ≥350 F g{sup −1} as compared with constituents (∼70 F g{sup −1}) at discharge current density of 0.3 A g{sup −1} that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM) technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting) and conducting polymers (semiconducting) backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to determine

  19. Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

    Science.gov (United States)

    Gupta, Sanju; Price, Carson

    2015-10-01

    Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL) assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO)1, (PPy/ErGO)1, (PAni/GO)1 and (PPy/GO)1. The rationale design is to create thin films that possess interconnected graphene nanosheets (GNS) with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, Cs, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent Cs of ≥350 F g-1 as compared with constituents (˜70 F g-1) at discharge current density of 0.3 A g-1 that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM) technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting) and conducting polymers (semiconducting) backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to determine electrochemical (re)activity of surface ion adsorption sites

  20. Fabrication of Hybrid Polymer Solar Cells By Inverted Structure Based on P3HT:PCBM Active Layer

    Directory of Open Access Journals (Sweden)

    Shobih Shobih

    2017-08-01

    Full Text Available Hybrid polymer solar cell has privilege than its conventional structure, where it usually has structure of (ITO/PEDOT:PSS/Active Layer/Al. In humid environment the PEDOT:PSS will absorb water and hence can easily etch the ITO. Therefore it is necessary to use an alternative method to avoid this drawback and obtain more stable polymer solar cells, namely by using hybrid polymer solar cells structure with an inverted device architecture from the conventional, by reversing the nature of charge collection. In this paper we report the results of the fabrication of inverted bulk heterojunction polymer solar cells based on P3HT:PCBM as active layer, utilizing ZnO interlayer as buffer layer between the ITO and active layer with a stacked structure of ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag. The ZnO interlayer is formed through short route, i.e. by dissolving ZnO nanoparticles powder in chloroform-methanol solvent blend rather than by sol-gel process. Based on the measurement results on electrical characteristics of inverted polymer solar cells under 500 W/m2 illumination and AM 1.5 direct filter at room temperature, cell with annealing process of active layer at 110 °C for 10 minutes results in higher cell performance than without annealing, with an open-circuit voltage of 0.21 volt, a short-circuit current density of 1.33 mA/cm2 , a fill factor of 43.1%, and a power conversion efficiency of 0.22%. The low cell’s performance is caused by very rough surface of ZnO interlayer.

  1. In situ corrosion monitoring of PC structures with distributed hybrid carbon fiber reinforced polymer sensors

    Science.gov (United States)

    Yang, C. Q.; Wu, Z. S.

    2007-08-01

    Firstly, the fabrication and sensing properties of hybrid carbon fiber reinforced polymer (HCFRP) composite sensors are addressed. In order to provide a distributed sensing manner, the HCFRP sensors were divided into multi-zones with electrodes, and each zone was regarded as a separate sensor. Secondly, their application is studied to monitor the steel corrosion of prestressed concrete (PC) beams. The HCFRP sensors with different gauge lengths were mounted on a PC tendon, steel bar and embedded in tensile and compressive sides of the PC beam. The experiment was carried out under an electric accelerated corrosion and a constant load of about 54 kN. The results reveal that the corrosion of the PC tendon can be monitored through measuring the electrical resistance (ER) change of the HCFRP sensors. For the sensors embedded in tensile side of the PC beam, their ER increases as the corrosion progresses, whereas for the sensors embedded in compressive side, their ER decreases with corrosion time. Moreover, the strains due to the corrosion can be obtained based on the ER change and calibration curves of HCFRP sensors. The strains measured with traditional strain gauges agree with the strains calculated from the ER changes of HCFRP sensors. The electrical behavior of the zones where the corrosion was performed is much different from those of the other zones. In these zones, either there exist jumps in ER, or the ER increases with a much larger rate than those of the other zones. Distributed corrosion monitoring for PC structures is thus demonstrated with the application of HCFRP sensors through a proper installation of multi-electrodes.

  2. Lysozyme-loaded lipid-polymer hybrid nanoparticles: preparation, characterization and colloidal stability evaluation.

    Science.gov (United States)

    Devrim, Burcu; Kara, Aslı; Vural, İmran; Bozkır, Asuman

    2016-11-01

    Lipid-polymer hybrid nanoparticles (LPNPs) are polymeric nanoparticles enveloped by lipid layers, which have emerged as a potent therapeutic nanocarrier alternative to liposomes and polymeric nanoparticles. The aim of this work was to develop, characterize and evaluate LPNPs to deliver a model protein, lysozyme. Lysozyme-loaded LPNPs were prepared by using the modified w/o/w double-emulsion-solvent-evaporation method. Poly-ɛ-caprolactone (PCL) was used as polymeric core material and tripalmitin:lechitin mixture was used to form a lipid shell around the LPNPs. LPNPs were evaluated for particle size distribution, zeta potential, morphology, encapsulation efficiency, in vitro drug release, stability and cytotoxicity. The DLS measurement results showed that the particle size of LPNPs ranged from 58.04 ± 1.95 nm to 2009.00 ± 0.52 nm. The AFM and TEM images of LPNPs demonstrate that LPNPs are spherical in shape. The protein-loading capacity of LPNPs ranged from 5.81% to 60.32%, depending on the formulation parameters. LPNPs displayed a biphasic drug release pattern with a burst release within 1 h, followed by sustained release afterward. Colloidal stability results of LPNPs in different media showed that particle size and zeta potential values of particles did not change significantly in all media except of FBS 100% for 120 h. Finally, the results of a cellular uptake study showed that LPNPs were significantly taken up by 83.3% in L929 cells. We concluded that the LPNPs prepared with PCL as polymeric core material and tripalmitin:lechitin mixture as lipid shell should be a promising choice for protein delivery.

  3. Pulmonary delivery of antitubercular drugs using spray-dried lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Bhardwaj, Ankur; Mehta, Shuchi; Yadav, Shailendra; Singh, Sudheer K; Grobler, Anne; Goyal, Amit Kumar; Mehta, Abhinav

    2016-09-01

    The present study aimed to develop lipid-polymer hybrid nanoparticles (LPNs) for the combined pulmonary delivery of isoniazid (INH) and ciprofloxacin hydrochloride (CIP HCl). Drug-loaded LPNs were prepared by the double-emulsification solvent evaporation method using the three-factor three-level Box-Behnken design. The optimized formulation had a size of 111.81 ± 1.2 nm, PDI of 0.189 ± 1.4, and PDE of 63.64 ± 2.12% for INH-loaded LPN, and a size of 172.23 ± 2.31 nm, PDI of 0.169 ± 1.23, and PDE of 68.49 ± 2.54% for CIP HCl-loaded LPN. Drug release was found to be sustained and controlled at lower pH and followed the Peppas model. The in vitro uptake study in alveolar macrophage (AM) showed that uptake of the drugs was increased significantly if administered in the form of LPN. The stability study proved the applications of adding PLGA in LPN as the polymeric core, which leads to a much more stable product as compared to other novel drug delivery systems. Spray drying was done to produce an inhalable, dry, powdered form of drug-loaded LPN. The spray-dried (SD) powder was equally capable of producing nano-aggregates having morphology, density, flowability and reconstitutibility in the range ideal for inhaled drug delivery. The nano aggregates produced by spray drying manifested their aerosolization efficiency in terms of the higher emitted dose and fine particle fraction with lower mass median aerodynamic diameter. The in vivo study using pharmacokinetic and pharmacodynamic approaches revealed that maximum internalization efficiency was achieved by delivering LPN in SD powdered forms by pulmonary route.

  4. Polymer-silica hybrids for separation of CO2 and catalysis of organic reactions

    Science.gov (United States)

    Silva Mojica, Ernesto

    spectroscopic investigation of the interactions of CO 2 with amine molecules under simulated CO2 capture conditions. Industrial CO2 capture processes involve fluidization and require degradation-resistant sorbents in the form of pellets. Agglomeration of silica-based CO2 capture sorbents involved the formulation of a polymer binder solution and the design of a scalable pelletization process. The characterization of these pellets revealed the formation of a CO 2-permeable polymer-silica network, which is resistant to attrition, and exhibits similar CO2 capture and degradation performance as the non-pelletized sorbents. The performance of these sorbents and pellets was tested in lab-scale and bench-scale adsorption units, using in-house fabricated fixed-bed and fluidized-bed reactors. A compartmental modeling technique was used to simulate the CO2 adsorption process and to elucidate the kinetic and thermodynamic parameters that impact the commercial viability of emerging CO2 capture technologies. The fundamental concepts and experimental techniques developed for the preparation of CO2 capture sorbents served as a basis for fabricating amine-functionalized polymer-silica hybrids for applications in catalysis of organic reactions. (i) Basic catalysts for carbon-carbon addition reactions were prepared by immobilization of amine molecules on silica supports. The activity of these catalysts and the mechanisms of base-catalyzed organic condensation reactions were investigated by an in-situ FTIR micro-scale reactor. (ii) Particle-loaded PVA composite membranes were selected for immobilization of glucose oxidase (GOx). GOx was immobilized by adsorption at pH values between 3.5 and 7.1. The results showed that adsorption was primarily achieved via hydrophobic interactions, and that PVA membranes loaded with amine-functionalized particles could help retain the activity of immobilized GOx by providing a proper hydrophilic/hydrophobic balance to the immobilized enzymes micro-environment.

  5. Self-assembled hybrid materials based on conjugated polymers and semiconductors nano-crystals for plastic solar cells

    International Nuclear Information System (INIS)

    Girolamo, J. de

    2007-11-01

    This work is devoted to the elaboration of self-assembled hybrid materials based on poly(3- hexyl-thiophene) and CdSe nano-crystals for photovoltaic applications. For that, complementary molecular recognition units were introduced as side chain groups on the polymer and at the nano-crystals' surface. Diamino-pyrimidine groups were introduced by post-functionalization of a precursor copolymer, namely poly(3-hexyl-thiophene-co-3- bromo-hexyl-thiophene) whereas thymine groups were introduced at the nano-crystals' surface by a ligand exchange reaction with 1-(6-mercapto-hexyl)thymine. However, due to their different solubility, the mixing of the two components by solution processes is difficult. A 'one-pot' procedure was developed, but this method led to insoluble aggregates without control of the hybrid composition. To overcome the solubility problem, the layer-by-layer method was used to prepare the films. This method allows a precise control of the deposition process. Experimental parameters were tested in order to evaluate their impact on the resulting film. The films morphology was investigated by microscopy and X-Ray diffraction techniques. These analyses reveal an interpenetrated structure of nano-crystals within the polymer matrix rather than a multilayered structure. Electrochemical and spectro electrochemical studies were performed on the hybrid material deposited by the LBL process. Finally the materials were tested in a solar cell configuration and the I=f(V) curves reveals a clear photovoltaic behaviour. (author)

  6. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals

    Directory of Open Access Journals (Sweden)

    Parul Chawla

    2014-08-01

    Full Text Available In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO and tri-n-octylphosphine (TOP and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern–Volmer quenching constant (KSV and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor–acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe. Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications.

  7. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals.

    Science.gov (United States)

    Chawla, Parul; Singh, Son; Sharma, Shailesh Narain

    2014-01-01

    In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe) chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO) and tri-n-octylphosphine (TOP) and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene) polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern-Volmer quenching constant (K SV) and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor-acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe). Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications.

  8. Refractive index modulation of SU-8 polymer optical waveguides by means of hybrid photothermal process

    OpenAIRE

    Salazar-Miranda, D.; Castillón, F. F.; Sánchez-Sánchez, J. J.; Angel-Valenzuela, J. L.; Márquez, H.

    2010-01-01

    This paper describes the fabrication and characterization of multimode polymer optical waveguides obtained using a SU-8-2005 polymer by means of photolithographic process. Critical information about refractive index modulation of polymer waveguides as function of fabrication parameters as pre-baked and ultraviolet exposure times is presented. Physical properties of the waveguides were determined by means prism-coupling technique, optical and SEM microscopy. Este trabajo describe la fabrica...

  9. Synthesis,crystal structure and properties of inorganic-organic hybrid polymers based on 8-hydroxylquinoline-5-sulfonic acid

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Two new inorganic-organic hybrid polymers, Mn(QS)(H2O) (1) and Co(QS)(H2O)2 (2) (H2QS=8-hydroxyl-quinoline-5-sulfonic acid), based on 8-hydroxylquinoline-5-sulfonate ligand, have been synthesized under solvothermal conditions and their structures were solved by single-crystal X-ray diffraction analysis. Compound 1 is a three-dimensional open framework with rutile topology structure, and compound 2 is a three-dimensional supramolecular structure. These compounds were characterized by powder XRD, infrared spectroscopy, thermogravimetric analysis, fluorescence properties and magnetism properties.

  10. Charge separation dynamics in a narrow band gap polymer-PbS nanocrystal blend for efficient hybrid solar cells

    OpenAIRE

    Piliego, Claudia; Manca, Marianna; Kroon, Renee; Yarema, Maksym; Szendrei, Krisztina; Andersson, Mats R.; Heiss, Wolfgang; Loi, Maria A.

    2012-01-01

    We have demonstrated efficient hybrid solar cells based on lead sulfide (PbS) nanocrystals and a narrow band gap polymer, poly[{2,5-bis(2-hexyldecyl)-2,3,5,6-tetrahydro-3,6-dioxopyrrolo[3,4-c]pyrrole-1,4-diyl}-alt-{[2,2'-(1,4-phenylene)bis-thiophene]-5,5'-diyl}], (PDPPTPT). An opportune mixing of the two materials led to the formation of an energetically favorable bulk hetero-junction with a broad spectral response. Using a basic device structure, we reached a power conversion efficiency of s...

  11. Organic-Inorganic Hybrid Polymers as Adsorbents for Removal of Heavy Metal Ions from Solutions: A Review

    Science.gov (United States)

    Samiey, Babak; Cheng, Chil-Hung; Wu, Jiangning

    2014-01-01

    Over the past decades, organic-inorganic hybrid polymers have been applied in different fields, including the adsorption of pollutants from wastewater and solid-state separations. In this review, firstly, these compounds are classified. These compounds are prepared by sol-gel method, self-assembly process (mesopores), assembling of nanobuilding blocks (e.g., layered or core-shell compounds) and as interpenetrating networks and hierarchically structures. Lastly, the adsorption characteristics of heavy metals of these materials, including different kinds of functional groups, selectivity of them for heavy metals, effect of pH and synthesis conditions on adsorption capacity, are studied. PMID:28788483

  12. Characterization of Selected Parameters of Organic-Inorganic Hybrid Membranes Based on Various Polymers and Nd-Fe-B Fillers

    Directory of Open Access Journals (Sweden)

    Rybak A.

    2016-12-01

    Full Text Available In this paper magnetic organic-inorganic hybrid membranes based on EC, PPO polymer matrices and various magnetic powder microparticles were synthesized and studied. Constant pressure permeation technique and the Time Lag method were used to obtain the gas transport coefficients. The mechanical, rheological and magnetic parameters of magnetic hybrid membranes were examined. It was found that their separation and gas transport properties (D, P, S and α were improved with the decrease in powder particle size and the increase of membrane’s remanence, saturation magnetization and magnetic particle filling. The increase of the magnetic powder addition and a decrease of its granulation improved also mechanical and rheological parameters of the tested membranes. This improvement also had a positive effect on their gas separation properties and their potential usage in the future.

  13. Nano-Protrusive Gold Nanoparticle-Hybridized Polymer Thin Film as a Sensitive, Multipatternable, and Antifouling Biosensor Platform.

    Science.gov (United States)

    Lee, Jeong-Hoon; Park, Byung-Soo; Ghang, Hyun-Gu; Song, Hyunjoon; Yang, Sung Yun

    2018-04-25

    Hybrid films consisting of anisotropic octahedral gold nanoparticles (AuNPs) and polymers had their surfaces functionalized and were immobilized on surface plasmon resonance (SPR) sensors for biomolecule detection. Specifically, carboxylated octahedral AuNPs (C-Oh-AuNPs) and poly(allylamine hydrochloride) (PAH) were assembled as ultrathin films by using a layer-by-layer process. The ionic strength generated from the functional groups of C-Oh-AuNP and PAH influenced the composition, its surface morphology, and the reactivity of the film toward further chemical reactions such as the synthesis of spherical AuNPs (S-AuNPs). We were thus able to control the size and the structure of the C-Oh-AuNP and S-AuNPs converted to nano-raspberry-shaped particles. This hierarchical AuNP hybrid film exhibits much more sensitive and stable detection of biomolecules than regular flat chip systems, and this result may be due to the SPR of the AuNP at its surface being able to markedly enhance the local optical field of the chip. The micropatterning of the hybrid coating was also studied by using a soft lithographic patterning method. We, in particular, worked on creating multiplex patterns having different combinations of shapes and fluorescent colors. We expect our hybrid coating system with multicode biomolecular arrays to be used as a powerful platform for biosensor applications.

  14. Preparation and morphological and optical characterization of azo-polymer-based SiO2 sonogel hybrid composites

    International Nuclear Information System (INIS)

    Morales-Saavedra, Omar G; Ontiveros-Barrera, Fernando G; Torres-Zúñiga, Vicente; Guadalupe-Bañuelos, José; Ortega-Martínez, Roberto; Rivera, Ernesto; García, Tonatiuh

    2009-01-01

    The well-established catalyst-free sonogel route was successfully implemented to fabricate highly pure, optically active, solid state polymeric azo- dye/SiO 2 -based hybrid composites. Bulk samples exhibit controllable geometrical shapes and monolithic structure with variable dopant concentrations. Since the implemented azo-dye chromophores exhibit a push–pull structure, hybrid film samples were spin-coated on ITO-covered glass substrates; molecular alignment was then performed via electrical poling in order to explore the quadratic nonlinear optical performance of this kind of composite. Comprehensive morphological, spectroscopic and optical characterization of the samples were performed with several experimental techniques: atomic force microscopy, x-ray diffraction and infrared, Raman, photoluminescent and ultraviolet–visible spectroscopies. The linear refractive indices of both bulk and thin film samples were measured according to the Brewster angle technique and a numerical analysis of the transmission spectral data, respectively. Regardless of the low glass transition temperatures of the studied polymers, some hybrid film samples were able to display stable nonlinear optical activity such as second harmonic generation. Results show that the chromophores were satisfactorily embedded into the highly pure SiO 2 sonogel network without significant guest–host molecular interactions, thus preserving their optical properties and producing sol–gel hybrid glasses suitable for optical applications

  15. A Numerical Study on Electrical Percolation of Polymer-Matrix Composites with Hybrid Fillers of Carbon Nanotubes and Carbon Black

    Directory of Open Access Journals (Sweden)

    Yuli Chen

    2014-01-01

    Full Text Available The electrical percolation of polymer-matrix composites (PMCs containing hybrid fillers of carbon nanotubes (CNTs and carbon black (CB is estimated by studying the connection possibility of the fillers using Monte Carlo simulation. The 3D simulation model of CB-CNT hybrid filler is established, in which CNTs are modeled by slender capped cylinders and CB groups are modeled by hypothetical spheres with interspaces because CB particles are always agglomerated. The observation on the effects of CB and CNT volume fractions and dimensions on the electrical percolation threshold of hybrid filled composites is then carried out. It is found that the composite electrical percolation threshold can be reduced by increasing CNT aspect ratio, as well as increasing the diameter ratio of CB groups to CNTs. And adding CB into CNT composites can decrease the CNT volume needed to convert the composite conductivity, especially when the CNT volume fraction is close to the threshold of PMCs with only CNT filler. Different from previous linear assumption, the nonlinear relation between CB and CNT volume fractions at composite percolation threshold is revealed, which is consistent with the synergistic effect observed in experiments. Based on the nonlinear relation, the estimating equation for the electrical percolation threshold of the PMCs containing CB-CNT hybrid fillers is established.

  16. A strong adjuvant based on glycol-chitosan-coated lipid-polymer hybrid nanoparticles potentiates mucosal immune responses against the recombinant Chlamydia trachomatis fusion antigen CTH522

    DEFF Research Database (Denmark)

    Rose, Fabrice; Erbo Wern, Jeanette; Gavins, Francesca

    2018-01-01

    with the cationic surfactant dimethyldioctadecylammonium bromide and the immunopotentiator trehalose-6,6'-dibehenate. Here we show that immunization with these lipid-polymer hybrid nanoparticles (LPNs) coated with the mucoadhesive polymer chitosan enhances mucosal immune responses. Glycol chitosan (GC......-specific IgG/IgA antibodies, together with CTH522-specific interferon γ-producing Th1 cells. This study demonstrates that mucosal administration of chitosan-coated LPNs represents a promising strategy to modulate the magnitude of mucosal vaccine responses....

  17. Polymer Hydrogel/Polybutadiene/Iron Oxide Nanoparticle Hybrid Actuators for the Characterization of NiTi Implants

    Directory of Open Access Journals (Sweden)

    Aleksandra Jeličić

    2009-03-01

    Full Text Available One of the main issues with the use of nickel titanium alloy (NiTi implants in cardiovascular implants (stents is that these devices must be of very high quality in order to avoid subsequent operations due to failing stents. For small stents with diameters below ca. 2 mm, however, stent characterization is not straightforward. One of the main problems is that there are virtually no methods to characterize the interior of the NiTi tubes used for fabrication of these tiny stents. The current paper reports on a robust hybrid actuator for the characterization of NiTi tubes prior to stent fabrication. The method is based on a polymer/hydrogel/magnetic nanoparticle hybrid material and allows for the determination of the inner diameter at virtually all places in the raw NiTi tubes. Knowledge of the inner structure of the raw NiTi tubes is crucial to avoid regions that are not hollow or regions that are likely to fail due to defects inside the raw tube. The actuator enables close contact of a magnetic polymer film with the inner NiTi tube surface. The magnetic signal can be detected from outside and be used for a direct mapping of the tube interior. As a result, it is possible to detect critical regions prior to expensive and slow stent fabrication processes.

  18. Polymer Combustion as a Basis for Hybrid Propulsion: A Comprehensive Review and New Numerical Approaches

    Directory of Open Access Journals (Sweden)

    Vasily Novozhilov

    2011-10-01

    Full Text Available Hybrid Propulsion is an attractive alternative to conventional liquid and solid rocket motors. This is an active area of research and technological developments. Potential wide application of Hybrid Engines opens the possibility for safer and more flexible space vehicle launching and manoeuvring. The present paper discusses fundamental combustion issues related to further development of Hybrid Rockets. The emphasis is made on the two aspects: (1 properties of potential polymeric fuels, and their modification, and (2 implementation of comprehensive CFD models for combustion in Hybrid Engines. Fundamentals of polymeric fuel combustion are discussed. Further, steps necessary to accurately describe their burning behaviour by means of CFD models are investigated. Final part of the paper presents results of preliminary CFD simulations of fuel burning process in Hybrid Engine using a simplified set-up.

  19. The parachute morphology as equilibrium morphology of vesicle-polymer hybrids?

    NARCIS (Netherlands)

    Jung, M.; Hubert, D.H.W.; Herk, van A.M.; German, A.L.

    2000-01-01

    Polymerisation in vesicles leads to novel polymer colloid morphologies. Two morphologies are currently reported: the triple-shell and the parachute morphology. The termodynamic analysis of these two morphologies, presented here, stresses the importance of considering interfacial energies between

  20. Hole transfer from CdSe nanoparticles to TQ1 polymer in hybrid solar cell device

    Science.gov (United States)

    Sohail, Muhammad; Shah, Zawar Hussain; Saeed, Shomaila; Bibi, Nasreen; Shahbaz, Sadia; Ahmed, Safeer; Shabbir, Saima; Siddiq, Muhammad; Iqbal, Azhar

    2018-05-01

    In view of realizing the economic viability, we fabricate a solar cell device containing low band gap and easily processable polymer 5-yl-8-(thiophene-2,5-diyl)-2,3-bis(3-(octyloxy)phenyl) quinoxaline (TQ1) and CdSe nanoparticles (NPs) and investigate its charge transport properties. When the TQ1 is combined with the CdSe NPs a strong photoluminescence quenching and shortening of photoluminescence lifetime of the TQ1 is observed indicating exciton transfer from TQ1 to the CdSe NPs. The time-resolved photoluminescence further reveals that the exciton transfer from the polymer to CdSe NPs is very efficient (68%) and it occurs in solar cell as compared to polymer only device. These observations suggest the importance of other II-VI semiconductor NPs to achieve higher efficiency for photovoltaic devices containing TQ1 polymer.

  1. Preparation and unique electrical behaviors of monodispersed hybrid nanorattles of metal nanocores with hairy electroactive polymer shells.

    Science.gov (United States)

    Cai, Tao; Zhang, Bin; Chen, Yu; Wang, Cheng; Zhu, Chun Xiang; Neoh, Koon-Gee; Kang, En-Tang

    2014-03-03

    A versatile template-assisted strategy for the preparation of monodispersed rattle-type hybrid nanospheres, encapsulating a movable Au nanocore in the hollow cavity of a hairy electroactive polymer shell (Au@air@PTEMA-g-P3HT hybrid nanorattles; PTEMA: poly(2-(thiophen-3-yl)ethyl methacrylate; P3HT: poly(3-hexylthiophene), was reported. The Au@silica core-shell nanoparticles, prepared by the modified Stöber sol-gel process on Au nanoparticle seeds, were used as templates for the synthesis of Au@silica@PTEMA core-double shell nanospheres. Subsequent oxidative graft polymerization of 3-hexylthiophene from the exterior surface of the Au@silica@PTEMA core-double shell nanospheres allowed the tailoring of surface functionality with electroactive P3HT brushes (Au@silica@PTEMA-g-P3HT nanospheres). The Au@air@ PTEMA-g-P3HT hybrid nanorattles were obtained after etching of the silica interlayer by HF. The as-prepared nanorattles were dispersed into an electrically insulating polystyrene matrix and for the first time used to fabricate nonvolatile memory devices. As a result, unique electrical behaviors, including insulator behavior, write-once-read-many-times and rewritable memory effects, and conductor behavior as well, were observed in the Al/Au@air@PTEMA-g-P3HT+PS/ITO (ITO: indium-tin oxide) sandwich thin-film devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hong [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China); Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072 (China); Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China)

    2010-07-01

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO{sub 2}) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO{sub 3}H{sub 2} groups on OPTi and the -NH{sub 2} groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm{sup -1} for DMFC application and a reduced methanol permeability of 5 x 10{sup -7} cm{sup 2} s{sup -1} at a 2 M methanol feed. (author)

  3. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Science.gov (United States)

    Wu, Hong; Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO 2) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO 3H 2 groups on OPTi and the -NH 2 groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm -1 for DMFC application and a reduced methanol permeability of 5 × 10 -7 cm 2 s -1 at a 2 M methanol feed.

  4. Development of polymer hybrid materials and analyzing techniques for their depletions

    International Nuclear Information System (INIS)

    Takaya, Haruo; Kobayashi, Yoshinori; Hirata, Koichi; Nakahara, Hisae; Kinugasa, Shinichi; Kamiya, Yoshinori

    1999-01-01

    The purpose of this research project was to develop new methods for evaluation and analysis of deterioration of polymer materials under radiological environment and its complicated environment including chemical effects. Furthermore, a screening and development for new radio-resistant polymer materials were attempted. In 1996, the third year of this project, the effects of γ-ray exposure on cardo-type polymers, novel high performance molecules were investigated and the early radiochemical changes due to the exposure were studied according to measurement of the life-time of cation. Cardo-type polymers were exposed to γ-ray and the changes in the molecular size and its distribution were analyzed by size exclusion chromatography and multi-angle laser light scattering (SEC/MALLS). Two cardo-type polymers, PI-BP and PA-T were used as the test subjects and polystyrene was as the standard control. Three membranes made from these three polymers were exposed to γ-ray at 0.2-1.2 MGy. The exposed membranes were applied onto SEC/MALLS after dissolving in NMP. The molecular weight of PI-BP was decreased as an increase of the radiation dose and there appeared a peak in a low molecular range when exposed at higher than 0.4 MGy. The molecular weight was decreased depending to the dose for all of the two cardo-type polymers and the control polystyrene sample. The ratio, Mw/Mn for PI-BP was decreased as an increase of the dose, whereas the ratio for PA-T was hardly changed by the exposure. On the contrary, the ratio for the polystyrene sample was greatly changed as an increase of the dose. These results suggest that various molecular-sized chains were produced by the exposure from the molecule, of which size was mono-dispersed before the exposure. (M.N.)

  5. Gas-Transport-Property Performance of Hybrid Carbon Molecular Sieve−Polymer Materials

    KAUST Repository

    Das, Mita; Perry, John D.; Koros, William J.

    2010-01-01

    agglomeration and residual stress, were addressed in this work, and subsequently a new membrane formation technique was developed to produce high-performing membranes. The successfully improved interfacial region of the hybrid membranes allows the sieves

  6. A Novel Synthesis of Gold Nanoparticles Supported on Hybrid Polymer/Metal Oxide as Catalysts for p-Chloronitrobenzene Hydrogenation

    Directory of Open Access Journals (Sweden)

    Cristian H. Campos

    2017-01-01

    Full Text Available This contribution reports a novel preparation of gold nanoparticles on polymer/metal oxide hybrid materials (Au/P[VBTACl]-M metal: Al, Ti or Zr and their use as heterogeneous catalysts in liquid phase hydrogenation of p-chloronitrobenzene. The support was prepared by in situ radical polymerization/sol gel process of (4-vinyl-benzyltrimethylammonium chloride and 3-(trimethoxysilylpropyl methacrylate in conjunction with metal-alkoxides as metal oxide precursors. The supported catalyst was prepared by an ion exchange process using chloroauric acid (HAuCl4 as gold precursor. The support provided the appropriate environment to induce the spontaneous reduction and deposition of gold nanoparticles. The hybrid material was characterized. TEM and DRUV-vis results indicated that the gold forms spherical metallic nanoparticles and that their mean diameter increases in the sequence, Au/P[VBTACl]-Zr > Au/P[VBTACl]-Al > Au/P[VBTACl]-Ti. The reactivity of the Au catalysts toward the p-CNB hydrogenation reaction is attributed to the different particle size distributions of gold nanoparticles in the hybrid supports. The kinetic pseudo-first-order constant values for the catalysts in the hydrogenation reaction increases in the order, Au/P[VBTACl]-Al > Au/P[VBTACl]-Zr > Au/P[VBTACl]-Ti. The selectivity for all the catalytic systems was greater than 99% toward the chloroaniline target product. Finally the catalyst supported on the hybrid with Al as metal oxide could be reused at least four times without loss in activity or selectivity for the hydrogenation of p-CNB in ethanol as solvent.

  7. A simple nanostructured polymer/ZnO hybrid solar cell - preparation and operation in air

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Thomann, Yi; Thomann, Ralf

    2008-01-01

    without notable loss in efficiency. The devices do not require any form of encapsulation to gain stability, while a barrier for mechanical protection may be useful. The devices are based on soluble zinc oxide nanoparticles mixed with the thermocleavable conjugated polymer poly-(3-(2-methylhexan-2-yl......A detailed description is given of the preparation of a polymer solar cell and its characterization. The solar cell can be prepared entirely in the ambient atmosphere by solution processing without the use of vacuum coating steps, and it can be operated in the ambient atmosphere with good...

  8. Photonics of a conjugated organometallic Pt-Ir polymer and its model compounds exhibiting hybrid CT excited states.

    Science.gov (United States)

    Soliman, Ahmed M; Fortin, Daniel; Zysman-Colman, Eli; Harvey, Pierre D

    2012-04-13

    Trans- dichlorobis(tri-n-butylphosphine)platinum(II) reacts with bis(2- phenylpyridinato)-(5,5'-diethynyl-2,2'-bipyridine)iridium(III) hexafluorophosphate to form the luminescent conjugated polymer poly[trans-[(5,5'-ethynyl-2,2'-bipyridine)bis(2- phenylpyridinato)-iridium(III)]bis(tri-n-butylphosphine)platinum(II)] hexafluorophosphate ([Pt]-[Ir])n. Gel permeation chromatography indicates a degree of polymerization of 9 inferring the presence of an oligomer. Comparison of the absorption and emission band positions and their temperature dependence, emission quantum yields, and lifetimes with those for models containing only the [Pt] or the [Ir] units indicates hybrid excited states including features from both chromophores. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Nb-TiO{sub 2}/polymer hybrid solar cells with photovoltaic response under inert atmosphere conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lira-Cantu, Monica; Khoda Siddiki, Mahbube; Munoz-Rojas, David; Amade, Roger [Centre d' Investigacio en Nanociencia i Nanotecnologia (CIN2, CSIC), Laboratory of Nanostructured Materials for Photovoltaic Energy, Campus UAB, Barcelona (Spain); Gonzalez-Pech, Natalia I. [Centre d' Investigacio en Nanociencia i Nanotecnologia (CIN2, CSIC), Laboratory of Nanostructured Materials for Photovoltaic Energy, Campus UAB, Barcelona (Spain); Instituto Tecnologico y de Estudios Superiores de Monterrey (ITESM), Ave. Eugenio Garza Sada, 64640 Monterrey, N.L. (Mexico)

    2010-07-15

    Hybrid Solar Cells (HSC) applying Nb-TiO{sub 2} in direct contact with a conducting organic polymer, MEH-PPV, show higher stability than the bare TiO{sub 2}-based HSC when analyzed under inert atmosphere conditions. IPCE analyses revealed that inert atmospheres affect directly the semiconductor oxide in the first stages of the analyses but photovoltaic performance stabilizes after several hours. A 20 wt% Nb-doped TiO{sub 2} presented the highest stability and photovoltaic properties. The behavior has been attributed to the solubility limit of Nb within the TiO{sub 2} beyond 20 wt% doping level where the co-existence of NbO{sub 2} is observed. The HSCs were analyzed under controlled N{sub 2} atmosphere and 1000 W/m{sup 2} (AM 1.5) irradiation. (author)

  10. Hierarchically structured transparent hybrid membranes by in situ growth of mesostructured organosilica in host polymer

    Science.gov (United States)

    Vallé, Karine; Belleville, Philippe; Pereira, Franck; Sanchez, Clément

    2006-02-01

    The elaborate performances characterizing natural materials result from functional hierarchical constructions at scales ranging from nanometres to millimetres, each construction allowing the material to fit the physical or chemical demands occurring at these different levels. Hierarchically structured materials start to demonstrate a high input in numerous promising applied domains such as sensors, catalysis, optics, fuel cells, smart biologic and cosmetic vectors. In particular, hierarchical hybrid materials permit the accommodation of a maximum of elementary functions in a small volume, thereby optimizing complementary possibilities and properties between inorganic and organic components. The reported strategies combine sol-gel chemistry, self-assembly routes using templates that tune the material's architecture and texture with the use of larger inorganic, organic or biological templates such as latex, organogelator-derived fibres, nanolithographic techniques or controlled phase separation. We propose an approach to forming transparent hierarchical hybrid functionalized membranes using in situ generation of mesostructured hybrid phases inside a non-porogenic hydrophobic polymeric host matrix. We demonstrate that the control of the multiple affinities existing between organic and inorganic components allows us to design the length-scale partitioning of hybrid nanomaterials with tuned functionalities and desirable size organization from ångström to centimetre. After functionalization of the mesoporous hybrid silica component, the resulting membranes have good ionic conductivity offering interesting perspectives for the design of solid electrolytes, fuel cells and other ion-transport microdevices.

  11. Hybrid fluorescent nanoparticles fabricated from pyridine-functionalized polyfluorene-based conjugated polymer as reversible pH probes over a broad range of acidity-alkalinity

    International Nuclear Information System (INIS)

    Cui, Haijun; Chen, Ying; Li, Lianshan; Tang, Zhiyong; Wu, Yishi; Fu, Hongbing; Tian, Zhiyuan

    2014-01-01

    Conjugated polymer nanoparticles (CPNs) were developed based on a polyfluorene-based conjugated polymer with thiophene units carrying pyridyl moieties incorporated in the backbone of polymer chains (PFPyT). Hybrid CPNs fabricated from PFPyT and an amphiphilic polymer (NP1) displayed pH-sensitive fluorescence emission features in the range from pH 4.8 to 13, which makes them an attractive nanomaterial for wide range optical sensing of pH values. The fluorescence of hybrid CPNs based on chemically close polyfluorene derivatives without pyridyl moieties (NP3), in contrast, remains virtually unperturbed by pH values in the same range. The fluorescence emission features of NP1 underwent fully reversible changes upon alternating acidification/basification of aqueous dispersions of the CPNs and also displayed excellent repeatability. The observed pH sensing properties of NP1 are attributed to protonation/deprotonation of the nitrogen atoms of the pyridine moieties. This, in turn, leads to the redistribution of electron density of pyridine moieties and their participation in the π-conjugation within the polymer main chains. The optically transparent amphiphilic polymers also exerted significant influence on the pH sensing features of the CPNs, likely by acting as proton sponge and/or acid chaperone. (author)

  12. Flexible organic/inorganic hybrid solar cells based on conjugated polymer and ZnO nanorod array

    International Nuclear Information System (INIS)

    Tong, Fei; Kim, Kyusang; Martinez, Daniel; Thapa, Resham; Ahyi, Ayayi; Williams, John; Park, Minseo; Kim, Dong-Joo; Lee, Sungkoo; Lim, Eunhee; Lee, Kyeong K

    2012-01-01

    We report on the photovoltaic characteristics of organic/inorganic hybrid solar cells fabricated on ‘flexible’ transparent substrates. The solar cell device is composed of ZnO nanorod array and the bulk heterojunction structured organic layer which is the blend of poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM). The ZnO nanorod array was grown on indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrates via a low-temperature (85 °C) aqueous solution process. The blend solution consisting of conjugated polymer P3HT and fullerene PCBM was spin coated at a low spinning rate of 400 rpm on top of the ZnO nanorod array structure and then the photoactive layer was slow dried at room temperature in air to promote its infiltration into the nanorod network. As a top electrode, silver was sputtered on top of the photoactive layer. The flexible solar cell with the structure of PET/ITO/ZnO thin film/ZnO nanorods/P3HT:PCBM/Ag exhibited a photovoltaic performance with an open circuit voltage (V OC ) of 0.52 V, a short circuit current density (J SC ) of 9.82 mA cm −2 , a fill factor (FF) of 35% and a power conversion efficiency (η) of 1.78%. All the measurements were performed under 100 mW cm −2 of illumination with an air mass 1.5 G filter. To the best of our knowledge, this is the first presentation of investigation into the fabrication and characterization of organic/inorganic hybrid solar cells based on bulk heterojunction structured conjugated polymer/fullerene photoactive layer and ZnO nanorod array constructed on flexible transparent substrates. (paper)

  13. Arginine-Glycine-Aspartic Acid-Modified Lipid-Polymer Hybrid Nanoparticles for Docetaxel Delivery in Glioblastoma Multiforme.

    Science.gov (United States)

    Shi, Kairong; Zhou, Jin; Zhang, Qianyu; Gao, Huile; Liu, Yayuan; Zong, Taili; He, Qin

    2015-03-01

    Hybrid nanoparticles consisting of lipids and the biodegradable polymer, poly (D,L-lactide-co-glycolide) (PLGA), were developed for the targeted delivery of the anticancer drug, docetaxel. Transmission electron microscopic observations confirmed the presence of a lipid coating over the polymeric core. Using coumarin-6 as a fluorescent probe, the uptake efficacy of RGD conjugated lipid coated nanoparticles (RGD-L-P) by C6 cells was increased significantly, compared with that of lipid-polymer hybrid nanoparticles (L-P; 2.5-fold higher) or PLGA-nanoparticles (PLGA-P; 1.76-fold higher). The superior tumor spheroid penetration of RGD-L-P indicated that RGD-L-P could target effectively and specifically to C6 cells overexpressing integrin α(v)β3. The anti-proliferative activity of docetaxel-loaded RGD-L-P against C6 cells was increased 2.69- and 4.13-fold compared with L-P and PLGA-P, respectively. Regarding biodistribution, the strongest brain-localized fluorescence signals were detected in glioblastoma multiforme (GBM)-bearing rats treated with 1,10-Dioctadecyl-3,3,30,30-tetramethylindotricarb-ocyanine iodide (DiR)-loaded RGD-L-P, compared to rats treated with DiR-loaded L-P or PLGA-P. The median survival time of GBM-bearing rats treated with docetaxel-loaded RGD-L-P was 57 days, a fold increase of 1.43, 1.78, 3.35, and 3.56 compared with animals given L-P (P PLGA-P (P < 0.05), Taxotere (P < 0.01) and saline (P < 0.01), respectively. Collectively, these results support RGD-L-P as a promising drug delivery system for the specific targeting and the treatment of GBM.

  14. Preparation of psoralen polymer-lipid hybrid nanoparticles and their reversal of multidrug resistance in MCF-7/ADR cells.

    Science.gov (United States)

    Huang, Qingqing; Cai, Tiange; Li, Qianwen; Huang, Yinghong; Liu, Qian; Wang, Bingyue; Xia, Xi; Wang, Qi; Whitney, John C C; Cole, Susan P C; Cai, Yu

    2018-11-01

    Multidrug resistance (MDR) is the leading cause of failure for breast cancer in the clinic. Thus far, polymer-lipid hybrid nanoparticles (PLN) loaded chemotherapeutic agents has been used to overcome MDR in breast cancer. In this study, we prepared psoralen polymer-lipid hybrid nanoparticles (PSO-PLN) to reverse drug resistant MCF-7/ADR cells in vitro and in vivo. PSO-PLN was prepared by the emulsification evaporation-low temperature solidification method. The formulation, water solubility and bioavailability, particle size, zeta potential and entrapment efficiency, and in vitro release experiments were optimized in order to improve the activity of PSO to reverse MDR. Optimal formulation: soybean phospholipids 50 mg, poly(lactic-co-glycolic) acid (PLGA) 15 mg, PSO 3 mg, and Tween-80 1%. The PSO-PLN possessed a round appearance, uniform size, exhibited no adhesion. The average particle size was 93.59 ± 2.87 nm, the dispersion co-efficient was 0.249 ± 0.06, the zeta potential was 25.47 ± 2.84 mV. In vitro analyses revealed that PSO resistance index was 3.2, and PSO-PLN resistance index was 5.6, indicating that PSO-PLN versus MCF-7/ADR reversal effect was significant. Moreover, PSO-PLN is somewhat targeted to the liver, and has an antitumor effect in the xenograft model of drug-resistant MCF-7/ADR cells. In conclusion, PSO-PLN not only reverses MDR but also improves therapeutic efficiency by enhancing sustained release of PSO.

  15. Hybrid tandem solar cells with depleted-heterojunction quantum dot and polymer bulk heterojunction subcells

    KAUST Repository

    Kim, Taesoo; Gao, Yangqin; Hu, Hanlin; Yan, Buyi; Ning, Zhijun; Jagadamma, Lethy Krishnan; Zhao, Kui; Kirmani, Ahmad R.; Eid, Jessica; Adachi, Michael M.; Sargent, Edward H.; Beaujuge, Pierre; Amassian, Aram

    2015-01-01

    with underlayers and associated constraints on the tandem architecture, and show that an adequate device configuration consists of a low bandgap CQD bottom cell and a high bandgap polymer:fullerene top cell. Once we optimize the recombination layer and individual

  16. Electroresponsive polymer-carbon nanotube hydrogel hybrids for pulsatile drug delivery in vivo.

    Science.gov (United States)

    Servant, Ania; Methven, Laura; Williams, Rhodri P; Kostarelos, Kostas

    2013-06-01

    Drug release triggered by an external non-invasive stimulus is of great interest for the development of new drug delivery systems. The preparation of an electroresponsive multiwalled carbon nanotube/poly(methylacrylic acid) (MWNT/PMAA)-based hybrid material is reported. The hydrogel hybrids achieve a controlled drug release upon the ON/OFF application of an electric field, giving rise to in vitro and in vivo pulsatile release profiles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Development and optimization of methotrexate-loaded lipid-polymer hybrid nanoparticles for controlled drug delivery applications.

    Science.gov (United States)

    Tahir, Nayab; Madni, Asadullah; Balasubramanian, Vimalkumar; Rehman, Mubashar; Correia, Alexandra; Kashif, Prince Muhammad; Mäkilä, Ermei; Salonen, Jarno; Santos, Hélder A

    2017-11-25

    Lipid-polymer hybrid nanoparticles (LPHNPs) are emerging platforms for drug delivery applications. In the present study, methotrexate loaded LPHNPs consisted of PLGA and Lipoid S100 were fabricated by employing a single-step modified nanoprecipitation method combined with self-assembly. A three factor, three level Box Behnken design using Design-Expert ® software was employed to access the influence of three independent variables on the particle size, drug entrapment and percent drug release. The optimized formulation was selected through numeric optimization approach. The results were supported with the ANOVA analysis, regression equations and response surface plots. Transmission electron microscope images indicated the nanosized and spherical shape of the LPHNPs with fair size distribution. The nanoparticles ranged from 176 to 308nm, which increased with increased polymer concentration. The increase in polymer and lipid concentration also increased the drug entrapment efficiency. The in vitro drug release was in range 70.34-91.95% and the release mechanism follow the Higuchi model (R 2 =0.9888) and Fickian diffusion (n<0.5). The in vitro cytotoxicity assay and confocal microscopy of the optimized formulation demonstrate the good safety and better internalization of the LPHNPs. The cell antiproliferation showed the spatial and controlled action of the nanoformulation as compared to the plain drug solution. The results suggest that LPHNPs can be a promising delivery system envisioned to safe, stable and potentially controlled delivery of methotrexate to the cancer cells to achieve better therapeutic outcomes. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Hybrid Nanocomposites of 2D Black Phosphorous Nanosheets Encapsulated in PMMA Polymer Material: New Platforms for Advanced Device Fabrication.

    Science.gov (United States)

    Telesio, Francesca; Passaglia, Elisa; Cicogna, Francesca; Costantino, Federica; Serrano-Ruiz, Manuel; Peruzzini, Maurizio; Heun, Stefan

    2018-04-12

    Hybrid materials, containing a 2D filler embedded in a polymeric matrix, are an interesting platform for several applications, because of the variety of properties that the filler can impart to the polymer matrix when dispersed at the nanoscale. Moreover, novel properties could arise from the interaction between the two. Mostly the bulk properties of these materials have been studied so far, especially focusing on how the filler changes the polymeric matrix properties. Here we propose a complete change of perspective by using the hybrid nanocomposite material as a platform suitable to engineer the properties of the filler and to exploit its potential in the fabrication of devices. As a proof of concept of the versatility and potentiality of the new method, we applied this approach to prepare black phosphorus nanocomposites through its dispersion in poly (methyl methacrylate). Black phosphorus is a very interesting 2D material, whose application have so far been limited by its very high reactivity to oxygen and water. In this respect, we show that electronic-grade black phosphorus flakes, already embedded in a protecting matrix since their exfoliation from the bulk material, are endowed with significant increased stability, and can be further processed into devices without degrading their properties. Creative Commons Attribution license.

  19. Hybrid nanocrystal/polymer solar cells based on tetrapod-shaped CdSexTe1-x nanocrystals

    International Nuclear Information System (INIS)

    Zhou Yi; Li Yunchao; Zhong Haizheng; Hou Jianhui; Ding Yuqin; Yang Chunhe; Li Yongfang

    2006-01-01

    A series of ternary tetrapodal nanocrystals of CdSe x Te 1-x with x = 0 (CdTe), 0.23, 0.53, 0.78, 1 (CdSe) were synthesized and used to fabricate hybrid nanocrystal/polymer solar cells. Herein, the nanocrystals acted as electron acceptors, and poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) was used as an electron donor. It was found that the open circuit voltage (V oc ), short-circuit current (J sc ) and power conversion efficiency (η) of the devices all increased with increasing Se content in the CdSe x Te 1-x nanocrystals under identical experimental conditions. The solar cell based on the blend of tetrapodal CdSe nanocrystals and MEH-PPV (9:1 w/w) showed the highest power conversion efficiency of 1.13% under AM 1.5, 80 mW cm -2 , and the maximum incident photon to converted current efficiency (IPCE) of the device reached 47% at 510 nm. The influence of nanocrystal composition on the photovoltaic properties of the hybrid solar cells was explained by the difference of the band level positions between MEH-PPV and the nanocrystals

  20. Crafting semiconductor organic-inorganic nanocomposites via placing conjugated polymers in intimate contact with nanocrystals for hybrid solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lei; Lin, Zhiqun [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

    2012-08-22

    Semiconductor organic-inorganic hybrid solar cells incorporating conjugated polymers (CPs) and nanocrystals (NCs) offer the potential to deliver efficient energy conversion with low-cost fabrication. The CP-based photovoltaic devices are complimented by an extensive set of advantageous characteristics from CPs and NCs, such as lightweight, flexibility, and solution-processability of CPs, combined with high electron mobility and size-dependent optical properties of NCs. Recent research has witnessed rapid advances in an emerging field of directly tethering CPs on the NC surface to yield an intimately contacted CP-NC nanocomposite possessing a well-defined interface that markedly promotes the dispersion of NCs within the CP matrix, facilitates the photoinduced charge transfer between these two semiconductor components, and provides an effective platform for studying the interfacial charge separation and transport. In this Review, we aim to highlight the recent developments in CP-NC nanocomposite materials, critically examine the viable preparative strategies geared to craft intimate CP-NC nanocomposites and their photovoltaic performance in hybrid solar cells, and finally provide an outlook for future directions of this extraordinarily rich field. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Application of nonlinear rheology to assess the effect of secondary nanofiller on network structure of hybrid polymer nanocomposites

    Science.gov (United States)

    Kamkar, Milad; Aliabadian, Ehsan; Shayesteh Zeraati, Ali; Sundararaj, Uttandaraman

    2018-02-01

    Carbon nanotube (CNT)/polymer nanocomposites exhibit excellent electrical properties by forming a percolated network. Adding a secondary filler can significantly affect the CNTs' network, resulting in changing the electrical properties. In this work, we investigated the effect of adding manganese dioxide nanowires (MnO2NWs) as a secondary nanofiller on the CNTs' network structure inside a poly(vinylidene fluoride) (PVDF) matrix. Incorporating MnO2NWs to PVDF/CNT samples produced a better state of dispersion of CNTs, as corroborated by light microscopy and transmission electron microscopy. The steady shear and oscillatory shear flows were employed to obtain a better insight into the nanofiller structure and viscoelastic behavior of the nanocomposites. The transient response under steady shear flow revealed that the stress overshoot of hybrid nanocomposites (two-fillers), PVDF/CNT/MnO2NWs, increased dramatically in comparison to binary nanocomposites (single-filler), PVDF/CNT and PVDF/MnO2NWs. This can be attributed to microstructural changes. Large amplitude oscillatory shear characterization was also performed to further investigate the effect of the secondary nanofiller on the nonlinear viscoelastic behavior of the samples. The nonlinear rheological observations were explained using quantitative nonlinear parameters [strain-stiffening ratio (S) and shear-thickening ratio (T)] and Lissajous-Bowditch plots. Results indicated that a more rigid nanofiller network was formed for the hybrid nanocomposites due to the better dispersion state of CNTs and this led to a more nonlinear viscoelastic behavior.

  2. Synthesis and Performances of Phase Change Microcapsules with a Polymer/Diatomite Hybrid Shell for Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Yanli Sun

    2018-05-01

    Full Text Available The mechanical behavior of phase-change microcapsules (microPCMs is of vital significance for practical applications in thermal energy storage. Hence, a new type of microPCMs based on an n-octadecane (C18 core and a melamine-urea-formaldehyde (MUF/diatomite hybrid shell was developed through in situ polymerization. Based on SEM micrographs, most microPCMs exhibited a nearly spherical and smooth microstructure, with broadened particle size distributions. It was confirmed by Fourier transform infrared (FTIR that successful polymerization of diatomite into the microPCMs occurred, and that additional diatomite had no effect on the core coated by the shell. In addition, the results of the differential scanning calorimeter (DSC and Atomic Force Microscopy (AFM demonstrated that the mechanical properties of the microPCMs were remarkably improved by the addition of a moderate amount of diatomite, but that the heat enthalpy and encapsulated efficiency (η decreased slightly. The incorporation of 2 wt % diatomite resulted in the average Young’s modulus of microPCMs, which was 1.64 times greater than those of microPCMs without diatomite. Furthermore, the melting and crystallization enthalpies and the encapsulated efficiency of the microPCMs were as high as 237.6 J/g, 234.4 J/g and 77.90%, respectively. The microPCMs with a polymer/diatomite hybrid shell may become the potential materials in the application of thermal energy storage.

  3. Engineering of a novel adjuvant based on lipid-polymer hybrid nanoparticles

    DEFF Research Database (Denmark)

    Rose, Fabrice; Wern, Jeanette Erbo; Ingvarsson, Pall Thor

    2015-01-01

    trehalose-6,6'-dibehenate (TDB) (CAF01) to tailor humoral and cellular immunity characterized by antibodies and Th1/Th17 responses. Such responses are important for the protection against diseases caused by intracellular bacteria such as Chlamydia trachomatis and Mycobacterium tuberculosis. The hybrid NPs...

  4. Hybrid metal grid-polymer-carbon nanotube electrodes for high luminance organic light emitting diodes

    International Nuclear Information System (INIS)

    Sam, F Laurent M; Dabera, G Dinesha M R; Lai, Khue T; Mills, Christopher A; Rozanski, Lynn J; Silva, S Ravi P

    2014-01-01

    Organic light emitting diodes (OLEDs) incorporating grid transparent conducting electrodes (TCEs) with wide grid line spacing suffer from an inability to transfer charge carriers across the gaps in the grids to promote light emission in these areas. High luminance OLEDs fabricated using a hybrid TCE composed of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS PH1000) or regioregular poly(3-hexylthiophene)-wrapped semiconducting single-walled carbon nanotubes (rrP3HT-SWCNT) in combination with a nanometre thin gold grid are reported here. OLEDs fabricated using the hybrid gold grid/PH1000 TCE have a luminance of 18 000 cd m −2 at 9 V; the same as the reference indium tin oxide (ITO) OLED. The gold grid/rrP3HT-SWCNT OLEDs have a lower luminance of 8260 cd m −2 at 9 V, which is likely due to a rougher rrP3HT-SWCNT surface. These results demonstrate that the hybrid gold grid/PH1000 TCE is a promising replacement for ITO in future plastic electronics applications including OLEDs and organic photovoltaics. For applications where surface roughness is not critical, e.g. electrochromic devices or discharge of static electricity, the gold grid/rrP3HT-SWCNT hybrid TCE can be employed. (paper)

  5. Development of hybrid polymer scaffolds for potential applications in ligament and tendon tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Sambit [Tissue Repair Lab, Division of Bioengineering, National University of Singapore, Singapore 117574 (Singapore); Cho-Hong, James Goh [Tissue Repair Lab, Division of Bioengineering, National University of Singapore, Singapore 117574 (Singapore); Siew-Lok, Toh [Tissue Repair Lab, Division of Bioengineering, National University of Singapore, Singapore 117574 (Singapore)

    2007-09-15

    Fibre-based scaffolds have been widely used for tendon and ligament tissue engineering. Knitted scaffolds have been proved to favour collagenous matrix deposition which is crucial for tendon/ligament reconstruction. However, such scaffolds have the limitation of being dependent on a gel system for cell seeding, which is unstable in a dynamic environment such as the knee joint. This study developed three types of hybrid scaffolds, based on knitted biodegradable polyester scaffolds, aiming to improve mechanical properties and cell attachment and proliferation on the scaffolds. The hybrid scaffolds were created by coating the knitted scaffolds with a thin film of poly ({epsilon}-caprolactone) (group I), poly (D, L-lactide-co-glycolide) nanofibres (group II) and type 1 collagen (group III). Woven scaffolds were also fabricated and compared with the various hybrid scaffolds in terms of their mechanical properties during in vitro degradation and cell attachment and growth. This study demonstrated that the coating techniques could modulate the mechanical properties and facilitate cell attachment and proliferation in the hybrid scaffold, which could be applied with promise in tissue engineering of tendons/ligaments.

  6. Development of hybrid polymer scaffolds for potential applications in ligament and tendon tissue engineering

    International Nuclear Information System (INIS)

    Sahoo, Sambit; Cho-Hong, James Goh; Siew-Lok, Toh

    2007-01-01

    Fibre-based scaffolds have been widely used for tendon and ligament tissue engineering. Knitted scaffolds have been proved to favour collagenous matrix deposition which is crucial for tendon/ligament reconstruction. However, such scaffolds have the limitation of being dependent on a gel system for cell seeding, which is unstable in a dynamic environment such as the knee joint. This study developed three types of hybrid scaffolds, based on knitted biodegradable polyester scaffolds, aiming to improve mechanical properties and cell attachment and proliferation on the scaffolds. The hybrid scaffolds were created by coating the knitted scaffolds with a thin film of poly (ε-caprolactone) (group I), poly (D, L-lactide-co-glycolide) nanofibres (group II) and type 1 collagen (group III). Woven scaffolds were also fabricated and compared with the various hybrid scaffolds in terms of their mechanical properties during in vitro degradation and cell attachment and growth. This study demonstrated that the coating techniques could modulate the mechanical properties and facilitate cell attachment and proliferation in the hybrid scaffold, which could be applied with promise in tissue engineering of tendons/ligaments

  7. Flexure Behavior of Hybrid Continuous Deep Beam Strengthened by Carbon Fiber Reinforced Polymer

    Directory of Open Access Journals (Sweden)

    Hayder M.K.Al-Mutairee

    2017-08-01

    Full Text Available This study present an experimental investigation for overall flexure behavior of reinforced concrete continuous deep beams (RCCDB made of hybrid concrete, normal strength concrete (NSC and high strength concrete (HSC at different location and percentage. The experimental work includes testing of sixteen specimens of RCCDB under two points loads. The effects of HSC layer thickness and CFRP on strength of RCCDB had been studied. The experimental results showed that the strengthening of RCCDB by HSC layer from top is better than from bottom, where the increment in the ultimate flexural strength increased by (14,21,27% for top strengthening and (12,15,13% for bottom strengthening for (25,50,75% thickness of total depth of beam respectively. The optimal strengthening of RCCDB by HSC layer at top was of 25%. The results also proved that the strengthening of hybrid RCCDB by (10,15cm CFRP strip at the bottom for flexure gave increment in the ultimate strength by (32, 29% respectively, and the strengthening by CFRP strip for flexure at the bottom is better than at top for hybrid RCCDB. The shear strengthening of hybrid RCCDB increases the ultimate strength by 23.4% and 13.8% if the strengthening has O and U shape respectively

  8. Influence of the polymer amount on bioactivity and biocompatibility of SiO{sub 2}/PEG hybrid materials synthesized by sol–gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Bollino, F.; Papale, F. [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Gallicchio, M.; Pacifico, S. [Department of Environmental Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta (Italy)

    2015-03-01

    SiO{sub 2}/PEG organic–inorganic hybrid materials, which differ in polyethylene glycol (PEG) content, were synthesized by sol–gel technique and the characterization of their structure and biological properties was carried out in order to evaluate the possible use in biomedical field. FT-IR spectroscopy detected that the two components of the hybrids (SiO{sub 2} and PEG) are linked by hydrogen bonds between the Si–OH groups of the inorganic phase and the terminal alcoholic groups and/or the ethereal oxygen atoms in the repeating units of polymer. X-ray diffraction analysis ascertained the amorphous nature of the gels and the observation of their morphology by SEM microscopy confirmed that the interpenetration of the two phases (organic and inorganic) occurs on nanometric scale. The biological characterization was carried out as a function of the polymer amount to study its influence on material behavior. The results showed that the synthesized materials were bioactive and biocompatible. The formation of a hydroxyapatite layer, indeed, was observed on their surface by SEM/EDX analysis after soaking in simulated body fluid. Moreover, the biocompatibility of SiO{sub 2}/PEG hybrids was assessed performing MTT and SRB cytotoxicity tests on fibroblast cell NIH 3T3 after 24 and 48 h of exposure, as well as Trypan Blue dye exclusion test. The response to the presence of the investigated materials was positive. The cell growth and proliferation showed dependence on polymer amount and time of exposure to the material extracts. Therefore, the obtained results are encouraging for the use of the obtained hybrids in dental or orthopedic applications. - Highlights: • SiO{sub 2}/PEG hybrid biomaterials synthesized by sol–gel method at various PEG percentages • Chemical and morphological characterization of hybrid materials • Chemical interactions between inorganic and organic components • Biological characterizations with MTT and SRB cytotoxicity tests

  9. Full-color tuning in binary polymer:perovskite nanocrystals organic-inorganic hybrid blends

    Science.gov (United States)

    Perulli, A.; Balena, A.; Fernandez, M.; Nedelcu, G.; Cretí, A.; Kovalenko, M. V.; Lomascolo, M.; Anni, M.

    2018-04-01

    The excellent optical and electronic properties of metal halide perovskites recently proposed these materials as interesting active materials for optoelectronic applications. In particular, the high color purity of perovskite colloidal nanocrystals (NCs) had recently motivated their exploration as active materials for light emitting diodes with tunable emission across the visible range. In this work, we investigated the emission properties of binary blends of conjugated polymers and perovskite NCs. We demonstrate that the emission color of the blends is determined by the superposition of the component photoluminescence spectra, allowing color tuning by acting on the blend relative composition. The use of two different polymers, two different perovskite NCs, and different blend compositions is exploited to tune the blend color in the blue-green, yellow-red, and blue-red ranges, including white light generation.

  10. Effect of hybrid polymer coating of Bioglass® foams on mechanical response during tensile loading

    Czech Academy of Sciences Publication Activity Database

    Bertolla, Luca; Chlup, Zdeněk; Stratil, Luděk; Boccaccini, A. R.; Dlouhý, Ivo

    2015-01-01

    Roč. 114, SEP (2015), S63-S68 ISSN 1743-6753 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 EU Projects: European Commission(XE) 264526 Institutional support: RVO:68081723 Keywords : Bioceramics * Bioglass scaffolds * Polymer coating * Composite coating * Mechanical properties * Cellulose * Tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.162, year: 2015

  11. Towards 4th generation biomaterials: a covalent hybrid polymer-ormoglass architecture

    Science.gov (United States)

    Sachot, N.; Mateos-Timoneda, M. A.; Planell, J. A.; Velders, A. H.; Lewandowska, M.; Engel, E.; Castaño, O.

    2015-09-01

    Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed on its surface mimicking the structure of the ECM of bone. Here, polylactic acid electrospun fibers have been successfully and reproducibly coated with a bioactive organically modified glass (ormoglass, Si-Ca-P2 system) covalently. In comparison with the pure polymeric mats, the fibers obtained showed improved hydrophilicity and mechanical properties, bioactive ion release, exhibited a nanoroughness and enabled good cell adhesion and spreading after just one day of culture (rMSCs and rEPCs). The fibers were coated with different ormoglass compositions to tailor their surface properties (roughness, stiffness, and morphology) by modifying the experimental parameters. Knowing that cells modulate their behavior according to the exposed physical and chemical signals, the development of this instructive material is a valuable advance in the design of functional regenerative biomaterials.Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed

  12. Transparent and flexible conducting hybrid film combined with 3-Aminopropyltriethoxysilane-coated polymer and graphene

    International Nuclear Information System (INIS)

    Jung, Daesung; Ko, Yong-Hun; Cho, Jumi; Adhikari, Prashanta Dhoj; Lee, Su Il; Kim, Yooseok; Song, Wooseok; Jung, Min Wook; Jang, Sung Won; Lee, Seung Youb; An, Ki-Seok; Park, Chong-Yun

    2015-01-01

    A simple approach to fabricate graphene hybrid film consisted of Graphene/3-aminopropyltriethoxysilane (APTES)/polyethylene terephthalate (PET) is presented, using self-assembled monolayers (SAMs) for enhancement of conductivity. The SAMs of APTES was prepared on ultraviolet-ozone (UVO)-irradiated PET films via wet chemical technique. The density of APTES was saturated after UV treatment time of 1 h for PET films; the carrier density and the optical transmittance were 9.3 × 10 12 /cm 2 and 82% for pristine graphene and 1.16 × 10 13 /cm 2 and 86% for graphene hybrid films, respectively, and experienced at inflection point at 30 min in UV treatment time. This behavior can be explained by surface morphology transition due to coalescence or clustering of mobile and low-molecular-weight oxidized components of PET.

  13. Silver nanoparticles containing hybrid polymer microgels with tunable surface plasmon resonance and catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ajmal, Muhammad; Siddiq, Mohammad [Quaid-I-Azam University, Islamabad (Pakistan); Farooqi, Zahoor Hussain [University of the Punjab, Lahore (Pakistan)

    2013-11-15

    Multi-responsive poly(N-isopropylacrylamide-methacrylic acid-acrylamide) [P(NIPAM-MAA-AAm)] copolymer microgel was prepared by free radical emulsion polymerization. Silver nanoparticles were fabricated inside the microgel network by in-situ reduction of silver nitrate. Swelling and deswelling behavior of the pure microgels was studied under various conditions of pH and temperature using dynamic light scattering. A red shift was observed in surface plasmon resonance wavelength of Ag nanoparticles with pH induced swelling of hybrid microgel. The catalytic activity of the hybrid system was investigated by monitoring the reduction of p-nitrophenol under different conditions of temperature and amount of catalysts. For this catalytic reaction a time delay of 8 to 10min was observed at room temperature, which was reduced to 2 min at high temperature due to swelling of microgels, which facilitated diffusion of reactants to catalyst surface and increased rate of reaction.

  14. Self-Assembly of 1D/2D Hybrid Nanostructures Consisting of a Cd(II Coordination Polymer and NiAl-Layered Double Hydroxides

    Directory of Open Access Journals (Sweden)

    Gonzalo Abellán

    2015-12-01

    Full Text Available The preparation and characterization of a novel hybrid material based on the combination of a 2D-layered double hydroxide (LDH nanosheets and a 1D-coordination polymer (1D-CP has been achieved through a simple mixture of suspensions of both building blocks via an exfoliation/restacking approach. The hybrid material has been thoroughly characterized demonstrating that the 1D-CP moieties are intercalated as well as adsorbed on the surface of the LDH, giving rise to a layered assembly with the coexistence of the functionalities of their initial constituents. This hybrid represents the first example of the assembly of 1D/2D nanomaterials combining LDH with CP and opens the door for a plethora of different functional hybrid systems.

  15. Photothermally Activated Pyroelectric Polymer Films for Harvesting of Solar Heat with a Hybrid Energy Cell Structure.

    Science.gov (United States)

    Park, Teahoon; Na, Jongbeom; Kim, Byeonggwan; Kim, Younghoon; Shin, Haijin; Kim, Eunkyoung

    2015-12-22

    Photothermal effects in poly(3,4-ethylenedioxythiophene)s (PEDOTs) were explored for pyroelectric conversion. A poled ferroelectric film was coated on both sides with PEDOT via solution casting polymerization of EDOT, to give highly conductive and effective photothermal thin films of PEDOT. The PEDOT films not only provided heat source upon light exposure but worked as electrodes for the output energy from the pyroelectric layer in an energy harvester hybridized with a thermoelectric layer. Compared to a bare thermoelectric system under NIR irradiation, the photothermal-pyro-thermoelectric device showed more than 6 times higher thermoelectric output with the additional pyroelectric output. The photothermally driven pyroelectric harvesting film provided a very fast electric output with a high voltage output (Vout) of 15 V. The pyroelectric effect was significant due to the transparent and high photothermal PEDOT film, which could also work as an electrode. A hybrid energy harvester was assembled to enhance photoconversion efficiency (PCE) of a solar cell with a thermoelectric device operated by the photothermally generated heat. The PCE was increased more than 20% under sunlight irradiation (AM 1.5G) utilizing the transmitted light through the photovoltaic cell as a heat source that was converted into pyroelectric and thermoelectric output simultaneously from the high photothermal PEDOT electrodes. Overall, this work provides a dynamic and static hybrid energy cell to harvest solar energy in full spectral range and thermal energy, to allow solar powered switching of an electrochromic display.

  16. Hybrid Solar Cell with TiO2 Film: BBOT Polymer and Copper Phthalocyanine as Sensitizer

    Directory of Open Access Journals (Sweden)

    Saptadip Saha

    2016-01-01

    Full Text Available An organic-inorganic hybrid solar cell was fabricated using Titanium dioxide (TiO2: 2,5-bis(5-tert-butyl-2-benzoxazolyl thiophene (BBOT film and Copper Phthalocyanine (CuPc as a sensitizer. BBOT was used in photodetector in other reported research works, but as per best of our knowledge, it was not implemented in solar cells till date. The blend of TiO2: BBOT blend was used to fabricate the film on ITO-coated glass and further a thin layer of CuPc was coated on the film. This was acted as photoanode and another ITO coated glass with a platinum coating was used as a counter electrode (cathode. An optimal blend of acetonitrile (solvent (50-100%, 1,3-dimethylimidazolium iodide (10-25%, iodine (2.5-10% and lithium iodide, pyridine derivative and thiocyanate was used as electrolytes in the hybrid solar cell. The different structural, optical and electrical characteristics were measured. The Hybrid solar cell showed a maximum conversion efficiency of 6.51%.

  17. Shape memory polymer hybrids of SBS/dl-PLA and their shape memory effects

    International Nuclear Information System (INIS)

    Zhang, Heng; Chen, Zhi; Zheng, Zheng; Zhu, Xiaomin; Wang, Haitao

    2013-01-01

    The hybrids of styrene-butadiene-styrene tri-block copolymer (SBS) and amorphous poly(dl-lactic acid) (dl-PLA) are found to exhibit shape memory effects, which gives an example of a dual-domain shape memory system consisting of an elastic domain and a thermo-switch domain. The dual-domain manner in this hybrid is studied by means of differential scanning calorimetry (DSC) and scanning electron microscope (SEM). Subsequently, the tensile test clarifies the interactions of the two domains on shape memory effects. As an elastic domain, SBS offers good shape recovery when its content exceeds 50 wt%. As a thermo-switch domain, dl-PLA triggers the shape memory effect at ca. 55 °C and offers good shape fixing when the content exceeds 30 wt%. An easy-to-do and easy-to-know feature of the hybrid is that the optimization of shape memory effect can be achieved by generating bicontinous phases of SBS and dl-PLA, in which the dl-PLA content ranges from 30 to 70 wt%. -- Highlights: ► The composite materials of SBS and amorphous dl-PLA were prepared by blending. ► A continuous domain was observed with the increasing content of dl-PLA. ► The composites exhibited shape memory effects.

  18. Engineering of a novel adjuvant based on lipid-polymer hybrid nanoparticles: A quality-by-design approach.

    Science.gov (United States)

    Rose, Fabrice; Wern, Jeanette Erbo; Ingvarsson, Pall Thor; van de Weert, Marco; Andersen, Peter; Follmann, Frank; Foged, Camilla

    2015-07-28

    properties of DDA/TDB are maintained in the PLGA hybrid matrix. This study demonstrates the complexity of formulation design for the engineering of a hybrid lipid-polymer nanoparticle adjuvant. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Memory effect of polymer dispersed liquid crystal by hybridization with nanoclay

    Directory of Open Access Journals (Sweden)

    2010-01-01

    Full Text Available The electro-optical performances of polymer dispersed liquid crystal (PDLC were investigated in the presence of organically modified clays. With the addition and increasing amount of modified clay, driving voltage and memory effect, viz. transparent state of the film after the electricity is off simultaneously increased due most likely to the increased viscosity. Among the two types of modifier, 4-(4-aminophenyl benzonitrile having greater chemical affinity with LC than hexylamine, gave finer dispersion of clay in liquid crystal, greater viscosity, larger driving voltage and response time, and greater memory effect.

  20. Development of PLA hybrid yarns for biobased self-reinforced polymer composites

    Science.gov (United States)

    Köhler, T.; Gries, T.; Seide, G.

    2017-10-01

    Lightweight materials are a necessity in various industries. Lightweight design is in the key interest of the mobility sector, e.g. the automotive and aerospace industry. This trend applies also for the consumer industries, e.g. sporting goods. In addition, the worldwide demand for replacing fossil-based materials has led to a significant growth of bioplastics. Due to their low mechanical performance and durability, their use is still limited. Therefore, it is necessary to develop biobased, sustainable polymeric materials with high stiffness, high impact and high durability without impairing recyclability at a similar price level of non-biobased solutions. Biobased self-reinforced polymer composites offer these unique properties.

  1. Advances in Hybrid Polymer-Based Materials for Sustained Drug Release

    Directory of Open Access Journals (Sweden)

    Lígia N. M. Ribeiro

    2017-01-01

    Full Text Available The use of biomaterials composed of organic pristine components has been successfully described in several purposes, such as tissue engineering and drug delivery. Drug delivery systems (DDS have shown several advantages over traditional drug therapy, such as greater therapeutic efficacy, prolonged delivery profile, and reduced drug toxicity, as evidenced by in vitro and in vivo studies as well as clinical trials. Despite that, there is no perfect delivery carrier, and issues such as undesirable viscosity and physicochemical stability or inability to efficiently encapsulate hydrophilic/hydrophobic molecules still persist, limiting DDS applications. To overcome that, biohybrid systems, originating from the synergistic assembly of polymers and other organic materials such as proteins and lipids, have recently been described, yielding molecularly planned biohybrid systems that are able to optimize structures to easily interact with the targets. This work revised the biohybrid DDS clarifying their advantages, limitations, and future perspectives in an attempt to contribute to further research of innovative and safe biohybrid polymer-based system as biomaterials for the sustained release of active molecules.

  2. Engineering of budesonide-loaded lipid-polymer hybrid nanoparticles using a quality-by-design approach.

    Science.gov (United States)

    Leng, Donglei; Thanki, Kaushik; Fattal, Elias; Foged, Camilla; Yang, Mingshi

    2017-08-25

    Chronic obstructive pulmonary disease (COPD) is a complex disease, characterized by persistent airflow limitation and chronic inflammation. The purpose of this study was to design lipid-polymer hybrid nanoparticles (LPNs) loaded with the corticosteroid, budesonide, which could potentially be combined with small interfering RNA (siRNA) for COPD management. Here, we prepared LPNs based on the biodegradable polymer poly(dl-lactic-co-glycolic acid) (PLGA) and the cationic lipid dioleyltrimethylammonium propane (DOTAP) using a double emulsion solvent evaporation method. A quality-by-design (QbD) approach was adopted to define the optimal formulation parameters. The quality target product profile (QTPP) of the LPNs was identified based on risk assessment. Two critical formulation parameters (CFPs) were identified, including the theoretical budesonide loading and the theoretical DOTAP loading. The CFPs were linked to critical quality attributes (CQAs), which included the intensity-based hydrodynamic particle diameter (z-average), the polydispersity index (PDI), the zeta-potential, the budesonide encapsulation efficiency, the actual budesonide loading and the DOTAP encapsulation efficiency. A response surface methodology (RSM) was applied for the experimental design to evaluate the influence of the CFPs on the CQAs, and to identify the optimal operation space (OOS). All nanoparticle dispersions displayed monodisperse size distributions (PDIPLGA increases when increasing the initial amount of budesonide. The OOS was modeled by applying the QTPP. The OOS had a budesonide encapsulation efficiency higher than 30%, a budesonide loading above 15μg budesonide/mg PLGA, a zeta-potential higher than 35mV and a DOTAP encapsulation efficiency above 50%. This study shows the importance of systematic formulation design for understanding the effect of formulation parameters on the characteristics of LPNs, eventually resulting in the identification of an OOS. Copyright © 2017 Elsevier B

  3. Hybrid calcium carbonate/polymer microparticles containing silver nanoparticles as antibacterial agents

    Science.gov (United States)

    Długosz, Maciej; Bulwan, Maria; Kania, Gabriela; Nowakowska, Maria; Zapotoczny, Szczepan

    2012-12-01

    We report here on synthesis and characterization of novel hybrid material consisting of silver nanoparticles (nAgs) embedded in calcium carbonate microparticles (μ-CaCO3) serving as carriers for sustained release. nAgs are commonly used as antimicrobial agents in many commercial products (textiles, cosmetics, and drugs). Although they are considered to be safe, their interactions with human organisms are still not fully understood; therefore it is important to apply them with caution and limit their presence in the environment. The synthesis of the new material was based on the co-precipitation of CaCO3 and nAg in the presence of poly(sodium 4-styrenesulfonate). Such designed system enables sustained release of nAg to the environment. This hybrid colloidal material (nAg/μ-CaCO3) was characterized by microscopic and spectroscopic methods. The release of nAg from μ-CaCO3 microparticles was followed in water at various pH values. Microbiological tests confirmed the effectiveness of these microparticles as an antibacterial agent. Importantly, the material can be stored as a dry powder and subsequently re-suspended in water without the risk of losing its antimicrobial activity. nAg/μ-CaCO3 was applied here to insure bacteriostatic properties of down feathers that may significantly prolong their lifetime in typical applications. Such microparticles may be also used as, e.g., components of coatings and paints protecting various surfaces against microorganism colonization.

  4. Hybrid calcium carbonate/polymer microparticles containing silver nanoparticles as antibacterial agents

    International Nuclear Information System (INIS)

    Długosz, Maciej; Bulwan, Maria; Kania, Gabriela; Nowakowska, Maria; Zapotoczny, Szczepan

    2012-01-01

    We report here on synthesis and characterization of novel hybrid material consisting of silver nanoparticles (nAgs) embedded in calcium carbonate microparticles (μ-CaCO 3 ) serving as carriers for sustained release. nAgs are commonly used as antimicrobial agents in many commercial products (textiles, cosmetics, and drugs). Although they are considered to be safe, their interactions with human organisms are still not fully understood; therefore it is important to apply them with caution and limit their presence in the environment. The synthesis of the new material was based on the co-precipitation of CaCO 3 and nAg in the presence of poly(sodium 4-styrenesulfonate). Such designed system enables sustained release of nAg to the environment. This hybrid colloidal material (nAg/μ-CaCO 3 ) was characterized by microscopic and spectroscopic methods. The release of nAg from μ-CaCO 3 microparticles was followed in water at various pH values. Microbiological tests confirmed the effectiveness of these microparticles as an antibacterial agent. Importantly, the material can be stored as a dry powder and subsequently re-suspended in water without the risk of losing its antimicrobial activity. nAg/μ-CaCO 3 was applied here to insure bacteriostatic properties of down feathers that may significantly prolong their lifetime in typical applications. Such microparticles may be also used as, e.g., components of coatings and paints protecting various surfaces against microorganism colonization.

  5. Discovery and in Vivo Evaluation of Novel RGD-Modified Lipid-Polymer Hybrid Nanoparticles for Targeted Drug Delivery

    Directory of Open Access Journals (Sweden)

    Yinbo Zhao

    2014-09-01

    Full Text Available In the current study, the lipid-shell and polymer-core hybrid nanoparticles (lpNPs modified by Arg–Gly–Asp(RGD peptide, loaded with curcumin (Cur, were developed by emulsification-solvent volatilization method. The RGD-modified hybrid nanoparticles (RGD–lpNPs could overcome the poor water solubility of Cur to meet the requirement of intravenous administration and tumor active targeting. The obtained optimal RGD-lpNPs, composed of PLGA (poly(lactic-co-glycolic acid–mPEG (methoxyl poly(ethylene- glycol, RGD–polyethylene glycol (PEG–cholesterol (Chol copolymers and lipids, had good entrapment efficiency, submicron size and negatively neutral surface charge. The core-shell structure of RGD–lpNPs was verified by TEM. Cytotoxicity analysis demonstrated that the RGD–lpNPs encapsulated Cur retained potent anti-tumor effects. Flow cytometry analysis revealed the cellular uptake of Cur encapsulated in the RGD–lpNPs was increased for human umbilical vein endothelial cells (HUVEC. Furthermore, Cur loaded RGD–lpNPs were more effective in inhibiting tumor growth in a subcutaneous B16 melanoma tumor model. The results of immunofluorescent and immunohistochemical studies by Cur loaded RGD–lpNPs therapies indicated that more apoptotic cells, fewer microvessels, and fewer proliferation-positive cells were observed. In conclusion, RGD–lpNPs encapsulating Cur were developed with enhanced anti-tumor activity in melanoma, and Cur loaded RGD–lpNPs represent an excellent tumor targeted formulation of Cur which might be an attractive candidate for cancer therapy.

  6. Discovery and in vivo evaluation of novel RGD-modified lipid-polymer hybrid nanoparticles for targeted drug delivery.

    Science.gov (United States)

    Zhao, Yinbo; Lin, Dayong; Wu, Fengbo; Guo, Li; He, Gu; Ouyang, Liang; Song, Xiangrong; Huang, Wei; Li, Xiang

    2014-09-29

    In the current study, the lipid-shell and polymer-core hybrid nanoparticles (lpNPs) modified by Arg-Gly-Asp(RGD) peptide, loaded with curcumin (Cur), were developed by emulsification-solvent volatilization method. The RGD-modified hybrid nanoparticles (RGD-lpNPs) could overcome the poor water solubility of Cur to meet the requirement of intravenous administration and tumor active targeting. The obtained optimal RGD-lpNPs, composed of PLGA (poly(lactic-co-glycolic acid))-mPEG (methoxyl poly(ethylene- glycol)), RGD-polyethylene glycol (PEG)-cholesterol (Chol) copolymers and lipids, had good entrapment efficiency, submicron size and negatively neutral surface charge. The core-shell structure of RGD-lpNPs was verified by TEM. Cytotoxicity analysis demonstrated that the RGD-lpNPs encapsulated Cur retained potent anti-tumor effects. Flow cytometry analysis revealed the cellular uptake of Cur encapsulated in the RGD-lpNPs was increased for human umbilical vein endothelial cells (HUVEC). Furthermore, Cur loaded RGD-lpNPs were more effective in inhibiting tumor growth in a subcutaneous B16 melanoma tumor model. The results of immunofluorescent and immunohistochemical studies by Cur loaded RGD-lpNPs therapies indicated that more apoptotic cells, fewer microvessels, and fewer proliferation-positive cells were observed. In conclusion, RGD-lpNPs encapsulating Cur were developed with enhanced anti-tumor activity in melanoma, and Cur loaded RGD-lpNPs represent an excellent tumor targeted formulation of Cur which might be an attractive candidate for cancer therapy.

  7. Protein permeation through polymer membranes for hybrid-type artificial pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Burczak, K; Fujisato, Toshiya; Ikada, Yoshito [Kyoto Univ. (Japan); Hatada, Motoyoshi

    1991-05-01

    Hydrogel membranes were prepared by radiation crosslinking of poly (vinyl alcohol) (PVA) in aqueous solutions. Effects of PVA concentration, PVA molecular weight, and radiation dose on the permeation of insulin and immunoglobulin through the membranes were investigated. Glucose permeation was also studied. The crosslinking density affected the size of macromolecular mesh of hydrogel network as well as the water content of membrane responsible for the diffusion of the solutes. The diffusion coefficient linearly increased for all the solutes with the increasing water content in PVA hydrogels, indicating that diffusion occurs primarily through the water hydrating the polymer network. The increase in crosslinking density of hydrogels by changing PVA molecular weight brought about the decrease in mesh size of the hydrogels, which, in turn, had an influence on the diffusion of immunoglobulin, but not of insulin and glucose. (author).

  8. Long-Term Stability of Photovoltaic Hybrid Perovskites achieved by Graphene Passivation via a Water- and Polymer-Free Graphene Transfer Method

    Science.gov (United States)

    Tseng, W.-S.; Jao, M.-H.; Hsu, C.-C.; Wu, C.-I.; Yeh, N.-C.

    Organic-inorganic hybrid perovskites such as CH3NH3PbX3 (X = I, Br) have been intensively studied in recent years because of their rapidly improving photovoltaic power conversion efficiency. However, severe instability of these materials in ambient environment has been a primary challenge for practical applications. To address this issue, we employ high-quality PECVD-grown graphene to passivate the hybrid perovskites. In contrast to existing processes for transferring graphene from the growth substrates to other surfaces that involve either polymer or water, which are incompatible with photovoltaic applications of these water-sensitive hybrid perovskites, we report here a new water- and polymer-free graphene transferring method. Studies of the Raman, x-ray and ultraviolet photoemission spectroscopy (XPS and UPS) demonstrated excellent quality of monolayer PECVD-grown graphene samples after their transfer onto different substrates with the water- and polymer-free processing method. In particular, graphene was successfully transferred onto the surface of CH3NH3PbI3 thin films with sample quality intact. Moreover, XPS and UPS studies indicated that even after 3 months, the fully graphene-covered perovskite films remained spectroscopically invariant, which was in sharp contrast to the drastic changes, after merely one week, in both the XPS and UPS of a control CH3NH3PbI3 sample without graphene protection. Beckman Inst. in Caltech. Dragon Gate Program in Taiwan.

  9. In-situ preparation of poly(ethylene oxide)/Li3PS4 hybrid polymer electrolyte with good nanofiller distribution for rechargeable solid-state lithium batteries

    Science.gov (United States)

    Chen, Shaojie; Wang, Junye; Zhang, Zhihua; Wu, Linbin; Yao, Lili; Wei, Zhenyao; Deng, Yonghong; Xie, Dongjiu; Yao, Xiayin; Xu, Xiaoxiong

    2018-05-01

    Nano-sized fillers in a polymer matrix with good distribution can play a positive role in improving polymer electrolytes in the aspects of ionic conductivity, mechanical property and electrochemical performance of Li-ion cells. Herein, polyethylene oxide (PEO)/Li3PS4 hybrid polymer electrolyte is prepared via a new in-situ approach. The ionic conductivities of the novel hybrid electrolytes with variable proportions are measured, and the optimal electrolyte of PEO-2%vol Li3PS4 presents a considerable ionic conductivity of 8.01 × 10-4 S cm-1 at 60 °C and an electrochemical window up to 5.1 V. The tests of DSC and EDXS reveal that the Li3PS4 nanoparticles with better distribution, as active fillers scattering in the PEO, exhibit a positive effect on the transference of lithium ion and electrochemical interfacial stabilities. Finally, the assembled solid-state LiFePO4/Li battery presents a decent cycling performance (80.9% retention rate after 325 cycles at 60 °C) and excellent rate capacities with 153, 143, 139 and 127 mAh g-1 at the discharging rate of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C. It is fully proved that it is an advanced strategy to preparing the new organic/inorganic hybrid electrolytes for lithium-ion batteries applications.

  10. 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.

  11. OLED Hybrid Integrated Polymer Microfluidic Biosensing for Point of Care Testing

    Directory of Open Access Journals (Sweden)

    Ashwin Acharya

    2015-09-01

    Full Text Available This paper reports a microfluidic platform with external hybrid integration of an organic light emitting diode (OLED as an excitation source. This device can be used as a simple and cost effective biosensing element. The device is capable of rapid in-situ detection of biological elements such as sensing of interaction of antigen with fluorescent tagged antibody conjugates. These portable microfluidic systems have great potential for use an OLED in a single chip with very high accuracy and sensitivity for various point-of-care (POC diagnosis and lab on a chip (LOC applications, as the miniaturization of the biosensor is essential for handling smaller sample volumes in order to achieve high throughput. The biosensing element was successfully tested to detect anti-sheep IgG conjugates tagged to Alexafluor using a fluorescence based immunoassay method.

  12. Hybrid calcium carbonate/polymer microparticles containing silver nanoparticles as antibacterial agents

    Energy Technology Data Exchange (ETDEWEB)

    Dlugosz, Maciej; Bulwan, Maria; Kania, Gabriela; Nowakowska, Maria; Zapotoczny, Szczepan, E-mail: zapotocz@chemia.uj.edu.pl [Jagiellonian University, Faculty of Chemistry (Poland)

    2012-12-15

    We report here on synthesis and characterization of novel hybrid material consisting of silver nanoparticles (nAgs) embedded in calcium carbonate microparticles ({mu}-CaCO{sub 3}) serving as carriers for sustained release. nAgs are commonly used as antimicrobial agents in many commercial products (textiles, cosmetics, and drugs). Although they are considered to be safe, their interactions with human organisms are still not fully understood; therefore it is important to apply them with caution and limit their presence in the environment. The synthesis of the new material was based on the co-precipitation of CaCO{sub 3} and nAg in the presence of poly(sodium 4-styrenesulfonate). Such designed system enables sustained release of nAg to the environment. This hybrid colloidal material (nAg/{mu}-CaCO{sub 3}) was characterized by microscopic and spectroscopic methods. The release of nAg from {mu}-CaCO{sub 3} microparticles was followed in water at various pH values. Microbiological tests confirmed the effectiveness of these microparticles as an antibacterial agent. Importantly, the material can be stored as a dry powder and subsequently re-suspended in water without the risk of losing its antimicrobial activity. nAg/{mu}-CaCO{sub 3} was applied here to insure bacteriostatic properties of down feathers that may significantly prolong their lifetime in typical applications. Such microparticles may be also used as, e.g., components of coatings and paints protecting various surfaces against microorganism colonization.

  13. Ni-polymer nanogel hybrid particles: A new strategy for hydrogen production from the hydrolysis of dimethylamine-borane and sodium borohydride

    International Nuclear Information System (INIS)

    Cai, Haokun; Liu, Liping; Chen, Qiang; Lu, Ping; Dong, Jian

    2016-01-01

    Efficient non-precious metal catalysts are crucial for hydrogen production from borohydride compounds in aqueous media via hydrogen atoms in water. A method for preparing magnetic polymer nanoparticles is developed in this study based on the chemical deposition of nickel onto hydrophilic polymer nanogels. High-resolution transmission electron microscopic and XPS analyses show that Ni exists mainly in the form of NiO in nanogels. Excellent catalytic activities of the nanoparticles are demonstrated for hydrogen generation from the hydrolysis of dimethylamine-borane and sodium borohydride in which the initial TOF (turn-over frequencies) are 376 and 1919 h"−"1, respectively. Kinetic studies also reveal an Arrhenius activation energy of 50.96 kJ mol"−"1 for the hydrolysis of dimethylamine-borane and 47.82 kJ mol"−"1 for the hydrolysis of sodium borohydride, which are lower than those catalyzed by Ru metal. Excellent reusability and the use of water for hydrogen production from dimethylamine-borane provide the additional benefit of using a hybrid catalyst. The principle illustrated in the present study offers a new strategy to explore polymer-transition metal hybrid particles for hydrogen energy technology. - Highlights: • Electroless Ni plating on polymer nanogels generated recyclable catalysts. • The Ni particles proved efficient for H_2 production from borohydride compounds. • The catalysts have lower activation energies than Ru for the hydrolysis. • Borohydride hydrolysis is more beneficial than dehydrogenation in organic solvent.

  14. Dual-Ligand Modified Polymer-Lipid Hybrid Nanoparticles for Docetaxel Targeting Delivery to Her2/neu Overexpressed Human Breast Cancer Cells.

    Science.gov (United States)

    Yang, Zhe; Tang, Wenxin; Luo, Xingen; Zhang, Xiaofang; Zhang, Chao; Li, Hao; Gao, Di; Luo, Huiyan; Jiang, Qing; Liu, Jie

    2015-08-01

    In this study, a dual-ligand polymer-lipid hybrid nanoparticle drug delivery vehicle comprised of an anti-HER2/neu peptide (AHNP) mimic with a modified HIV-1 Tat (mTAT) was established for the targeted treatment of Her2/neu-overexpressing cells. The resultant dual-ligand hybrid nanoparticles (NPs) consisted of a poly(lactide-co-glycolide) core, a near 90% surface coverage of the lipid monolayer, and a 5.7 nm hydrated polyethylene glycol shell. Ligand density optimization study revealed that cellular uptake efficiency of the hybrid NPs could be manipulated by controlling the surface-ligand densities. Furthermore, the cell uptake kinetics and mechanism studies showed that the dual-ligand modifications of hybrid NPs altered the cellular uptake pathway from caveolae-mediated endocytosis (CvME) to the multiple endocytic pathways, which would significantly enhance the NP internalization. Upon the systemic investigation of the cellular uptake behavior of dual-ligand hybrid NPs, docetaxel (DTX), a hydrophobic anticancer drug, was successfully encapsulated into dual-ligand hybrid NPs with high drug loading for Her2/neu-overexpressing SK-BR-3 breast cancer cell treatment. The DTX-loaded dual-ligand hybrid NPs showed a decreased burst release and a more gradual sustained drug release property. Because of the synergistic effect of dual-ligand modification, DTX-loaded dual-ligand hybrid NPs exerted substantially better therapeutic potency against SK-BR-3 cancer cells than other NP formulations and free DTX drugs. These results demonstrate that the dual-ligand hybrid NPs could be a promising vehicle for targeted drug delivery to treat breast cancer.

  15. C,N-bipyrazole receptor grafted onto a porous silica surface as a novel adsorbent based polymer hybrid.

    Science.gov (United States)

    Radi, Smaail; Attayibat, Ahmed; El-Massaoudi, Mohamed; Bacquet, Maryse; Jodeh, Shehdeh; Warad, Ismail; Al-Showiman, Salim S; Mabkhot, Yahia N

    2015-10-01

    A simple heterogeneous synthesis of pure adsorbent based polymer hybrid made by condensing a functionalized C,N-bipyrazole with a 3-glycidoxypropyl-trimethoxysilane silylant agent, previously anchored on a silica surface was developed. The formed material (SG2P) was characterized through elemental analysis, FT-IR spectroscopy, (13)C NMR of solid state, scanning electron microscope (SEM), and was studied and evaluated by determination of the surface area using the BET equation, the adsorption and desorption capability using the isotherm of nitrogen and B.J.H. pore sizes. The new material exhibits good thermal stability determined by thermogravimetry curves and good chemical stability was examined in various acidic and buffer solutions (pH 1-7). The binding and adsorption abilities of SG2P were investigated for Hg(2+), Cd(2+), Pb(2+), Zn(2+), K(+), Na(+) and Li(+) cations and compared to the results of classical liquid-liquid extraction with the unbound C,N-bipyrazole compound. The grafting at the surface of silica does not affect complexing properties of the ligand and the SG2P exhibits a high selectivity toward Hg(2+) ion with no complexation being observed towards zinc and alkali metals. The extracted and the complexing cation percentages were determined by atomic absorption measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Enzyme-assisted growth of nacreous CaCO3/polymer hybrid nanolaminates via the formation of mineral bridges

    Science.gov (United States)

    Yeom, Bongjun; Char, Kookheon

    2016-06-01

    Laminated nanostructures in nacre have been adopted as models in the fabrication of strong, tough synthetic nanocomposites. However, the utilization of CaCO3 biominerals in these composites is limited by the complexity of the synthesis method for nanosized biominerals. In this study, we use the enzymatic reaction of urease to generate a nanoscale CaCO3 thin film to prepare CaCO3/polymer hybrid nanolaminates. Additional layers of CaCO3 thin film are consecutively grown over the base CaCO3 layer with the intercalation of organic layers. The morphology and crystallinity of the added CaCO3 layers depend strongly on the thickness of the organic layer coated on the underlying CaCO3 layer. When the organic layer is less than 20 nm thick, the amorphous CaCO3 layer is spontaneously transformed into crystalline calcite layer during the growth process. We also observe crystalline continuity between adjacent CaCO3 layers through interconnecting mineral bridges. The formation of these mineral bridges is crucial to the epitaxial growth of CaCO3 layers, similar to the formation of natural nacre.

  17. Improving polymer/nanocrystal hybrid solar cell performance via tuning ligand orientation at CdSe quantum dot surface.

    Science.gov (United States)

    Fu, Weifei; Wang, Ling; Zhang, Yanfang; Ma, Ruisong; Zuo, Lijian; Mai, Jiangquan; Lau, Tsz-Ki; Du, Shixuan; Lu, Xinhui; Shi, Minmin; Li, Hanying; Chen, Hongzheng

    2014-11-12

    Achieving superior solar cell performance based on the colloidal nanocrystals remains challenging due to their complex surface composition. Much attention has been devoted to the development of effective surface modification strategies to enhance electronic coupling between the nanocrystals to promote charge carrier transport. Herein, we aim to attach benzenedithiol ligands onto the surface of CdSe nanocrystals in the "face-on" geometry to minimize the nanocrystal-nanocrystal or polymer-nanocrystal distance. Furthermore, the "electroactive" π-orbitals of the benzenedithiol are expected to further enhance the electronic coupling, which facilitates charge carrier dissociation and transport. The electron mobility of CdSe QD films was improved 20 times by tuning the ligand orientation, and high performance poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT):CdSe nanocrystal hybrid solar cells were also achieved, showing a highest power conversion efficiency of 4.18%. This research could open up a new pathway to improve further the performance of colloidal nanocrystal based solar cells.

  18. Spin coating and plasma process for 2.5D and hybrid 3D micro-resonators on multilayer polymers

    Science.gov (United States)

    Bêche, B.; Gaviot, E.; Godet, C.; Zebda, A.; Potel, A.; Barbe, J.; Camberlein, L.; Vié, V.; Panizza, P.; Loas, G.; Hamel, C.; Zyss, J.; Huby, N.

    2009-05-01

    We have designed and realized three integrated photonic families of micro-resonators (MR) on multilayer organic materials. Such so-called 2.5D-MR and 3D-MR structures show off radius values ranging from 40 to 200μm. Both first and second families are especially designed on organic multilayer materials and shaped as ring- and disk-MR organics structures arranged upon (and coupled with) a pair of SU8-organic waveguides. The third family is related to hybrid 3D-MR structures composed of spherical glass-MR coupled to organic waveguides by a Langmuir-Blodgett lipid film about three nanometers in thickness. At first, polymer spin coating, surface plasma treatment and selective UV-lithography processes have been developed to realize 2.5D photonic micro-resonators. Secondly, we have designed and characterized photonic-quadripoles made of 3D-glass-MR arranged upon a pair of SU8 waveguides. Such structures are defined by a 4-ports or 4-waveguides coupled by the spherical glass-MR. We have achieved an evanescent photonic coupling between the 3D-MR and the 4-ports structure. Spectral resonances have been measured for 4-whispering gallery-modes (WGM) into such 3D-structures respectively characterized by a 0.97 nm free spectral range (FSR) and a high quality Q-factor up to 4.104.

  19. EnVision+, a new dextran polymer-based signal enhancement technique for in situ hybridization (ISH).

    Science.gov (United States)

    Wiedorn, K H; Goldmann, T; Henne, C; Kühl, H; Vollmer, E

    2001-09-01

    Seventy paraffin-embedded cervical biopsy specimens and condylomata were tested for the presence of human papillomavirus (HPV) by conventional in situ hybridization (ISH) and ISH with subsequent signal amplification. Signal amplification was performed either by a commercial biotinyl-tyramide-based detection system [GenPoint (GP)] or by the novel two-layer dextran polymer visualization system EnVision+ (EV), in which both EV-horseradish peroxidase (EV-HRP) and EV-alkaline phosphatase (EV-AP) were applied. We could demonstrate for the first time, that EV in combination with preceding ISH results in a considerable increase in signal intensity and sensitivity without loss of specificity compared to conventional ISH. Compared to GP, EV revealed a somewhat lower sensitivity, as measured by determination of the integrated optical density (IOD) of the positively stained cells. However, EV is easier to perform, requires a shorter assay time, and does not raise the background problems that may be encountered with biotinyl-tyramide-based amplification systems. (J Histochem Cytochem 49:1067-1071, 2001)

  20. White-emissive tandem-type hybrid organic/polymer diodes with (0.33, 0.33) chromaticity coordinates.

    Science.gov (United States)

    Guo, Tzung-Fang; Wen, Ten-Chin; Huang, Yi-Shun; Lin, Ming-Wei; Tsou, Chuan-Cheng; Chung, Chia-Tin

    2009-11-09

    This study reports fabrication of white-emissive, tandem-type, hybrid organic/polymer light-emitting diodes (O/PLED). The tandem devices are made by stacking a blue-emissive OLED on a yellow-emissive phenyl-substituted poly(para-phenylene vinylene) copolymer-based PLED and applying an organic oxide/Al/molybdenum oxide (MoO(3)) complex structure as a connecting structure or charge-generation layer (CGL). The organic oxide/Al/MoO(3) CGL functions as an effective junction interface for the transport and injection of opposite charge carriers through the stacked configuration. The electroluminescence (EL) spectra of the tandem-type devices can be tuned by varying the intensity of the emission in each emissive component to yield the visible-range spectra from 400 to 750 nm, with Commission Internationale de l'Eclairage chromaticity coordinates of (0.33, 0.33) and a high color rendering capacity as used for illumination. The EL spectra also exhibit good color stability under various bias conditions. The tandem-type device of emission with chromaticity coordinates, (0.30, 0.31), has maximum brightness and luminous efficiency over 25,000 cd/m(2) and approximately 4.2 cd/A, respectively.

  1. Local anesthetic effects of bupivacaine loaded lipid-polymer hybrid nanoparticles: In vitro and in vivo evaluation.

    Science.gov (United States)

    Ma, Pengju; Li, Ting; Xing, Huaixin; Wang, Suzhen; Sun, Yingui; Sheng, Xiugui; Wang, Kaiguo

    2017-05-01

    There is a compelling need for prolonged local anesthetic that would be used for analgesia with a single administration. However, due to the low molecular weight of local anesthetics (LA) (lidocaine, bupivacaine, procaine, dibucaine, etc), they present fast systemic absorption. The aim of the present study was to develop and evaluate bupivacaine lipid-polymer hybrid nanoparticles (BVC LPNs), and compared with BVC loaded PLGA nanoparticles (BVC NPs). Their morphology, particle size, zeta potential and drug loading capacity were evaluated. In vitro release study, stability and cytotoxicity were studied. In vivo evaluation of anesthetic effects was performed on animal models. A facile nanoprecipitation and self-assembly method was optimized to obtain BVC LPNs, composed of PLGA, lecithin and DSPE-PEG 2000 , of ∼175nm particle size. Compared to BVC NPs, BVC LPNs exhibited prolonged in vitro release in phosphate-buffered saline (pH=7.4). Further, BVC LPNs displayed enhanced in vitro stability in 10% FBS and lower cytotoxicity (the concentration of BVC ranging from 1.0μM to 20μM). In addition, BVC LPNs exhibited significantly prolonged analgesic duration. These results demonstrate that the LPNs could function as promising drug delivery system for overcoming the drawbacks of poor stability and rapid drug leakage, and prolonging the anesthetic effect with slight toxicity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Hybrid conducting polymer materials incorporating poly-oxo-metalates for extraction of actinides; Materiaux polymeres conducteurs hybrides incorporant des polyoxometallates pour l'extraction d'actinides

    Energy Technology Data Exchange (ETDEWEB)

    Racimor, D

    2003-09-15

    The preparation and characterization of hybrid conducting polymers incorporating poly-oxo-metalates for extracting actinides is discussed. A study of the coordination of various lanthanide cations (Ce(III), Ce(IV), Nd(III)) by the mono-vacant poly-oxo-metalate {alpha}{sub 2}-[P{sub 2}W{sub 17}O{sub 61}]{sup 10-} showed significant differences according to the cation.. Various {alpha}-A-[PW{sub 9}O{sub 34}(RPO){sub 2}]{sup 5-} hybrids were synthesized and their affinity for actinides or lanthanides was demonstrated through complexation. The first hybrid poly-oxo-metallic lanthanide complexes were then synthesized, as was the first hybrid functionalized with a pyrrole group. The electro-polymerization conditions of this pyrrole remain still to be optimized. Poly-pyrrole materials incorporating {alpha}{sub 2}-[P{sub 2}W{sub 17}O{sub 61}]{sup 10-} or its neodymium or cerium complexes as doping agents proved to be the first conducting polymer incorporating poly-oxo-metalates capable of extracting plutonium from nitric acid. (author)

  3. Asymmetric Hybrid Polymer-Lipid Giant Vesicles as Cell Membrane Mimics.

    Science.gov (United States)

    Peyret, Ariane; Ibarboure, Emmanuel; Le Meins, Jean-François; Lecommandoux, Sebastien

    2018-01-01

    Lipid membrane asymmetry plays an important role in cell function and activity, being for instance a relevant signal of its integrity. The development of artificial asymmetric membranes thus represents a key challenge. In this context, an emulsion-centrifugation method is developed to prepare giant vesicles with an asymmetric membrane composed of an inner monolayer of poly(butadiene)- b -poly(ethylene oxide) (PBut- b -PEO) and outer monolayer of 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine (POPC). The formation of a complete membrane asymmetry is demonstrated and its stability with time is followed by measuring lipid transverse diffusion. From fluorescence spectroscopy measurements, the lipid half-life is estimated to be 7.5 h. Using fluorescence recovery after photobleaching technique, the diffusion coefficient of 1,2-dioleoyl- sn -glycero-3-phosphoethanolamine- N -(lissamine rhodamine B sulfonyl) (DOPE-rhod, inserted into the POPC leaflet) is determined to be about D = 1.8 ± 0.50 μm 2 s -1 at 25 °C and D = 2.3 ± 0.7 μm 2 s -1 at 37 °C, between the characteristic values of pure POPC and pure polymer giant vesicles and in good agreement with the diffusion of lipids in a variety of biological membranes. These results demonstrate the ability to prepare a cell-like model system that displays an asymmetric membrane with transverse and translational diffusion properties similar to that of biological cells.

  4. Mechanical properties of carbon fibre-reinforced polymer/magnesium alloy hybrid laminates

    Science.gov (United States)

    Zhou, Pengpeng; Wu, Xuan; Pan, Yingcai; Tao, Ye; Wu, Guoqing; Huang, Zheng

    2018-04-01

    In this study, we prepared fibre metal laminates (FMLs) consisting of high-modulus carbon fibre-reinforced polymer (CFRP) prepregs and thin AZ31 alloy sheets by using hot-pressing technology. Tensile and low-velocity impact tests were performed to evaluate the mechanical properties and fracture behaviour of the magnesium alloy-based FMLs (Mg-FMLs) and to investigate the differences in the fracture behaviour between the Mg-FMLs and traditional Mg-FMLs. Results show that the Mg-FMLs exhibit higher specific tensile strength and specific tensile modulus than traditional Mg-FMLs and that the tensile behaviour of the Mg-FMLs is mainly governed by the CFRP because of the combination of high interlaminar shear properties and thin magnesium alloy layers. The Mg-FMLs exhibit excellent bending stiffness. Hence, no significant difference between the residual displacement d r and indentation depth d i , and the permanent deformation is mainly limited to a small zone surrounding the impact location after the impact tests.

  5. Embroidered polymer-collagen hybrid scaffold variants for ligament tissue engineering.

    Science.gov (United States)

    Hoyer, M; Drechsel, N; Meyer, M; Meier, C; Hinüber, C; Breier, A; Hahner, J; Heinrich, G; Rentsch, C; Garbe, L-A; Ertel, W; Schulze-Tanzil, G; Lohan, A

    2014-10-01

    Embroidery techniques and patterns used for scaffold production allow the adaption of biomechanical scaffold properties. The integration of collagen into embroidered polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) scaffolds could stimulate neo-tissue formation by anterior cruciate ligament (ACL) cells. Therefore, the aim of this study was to test embroidered P(LA-CL) and PDS scaffolds as hybrid scaffolds in combination with collagen hydrogel, sponge or foam for ligament tissue engineering. ACL cells were cultured on embroidered P(LA-CL) and PDS scaffolds without or with collagen supplementation. Cell adherence, vitality, morphology and ECM synthesis were analyzed. Irrespective of thread size, ACL cells seeded on P(LA-CL) scaffolds without collagen adhered and spread over the threads, whereas the cells formed clusters on PDS and larger areas remained cell-free. Using the collagen hydrogel, the scaffold colonization was limited by the gel instability. The collagen sponge layers integrated into the scaffolds were hardly penetrated by the cells. Collagen foams increased scaffold colonization in P(LA-CL) but did not facilitate direct cell-thread contacts in the PDS scaffolds. The results suggest embroidered P(LA-CL) scaffolds as a more promising basis for tissue engineering an ACL substitute than PDS due to superior cell attachment. Supplementation with a collagen foam presents a promising functionalization strategy. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Lignin Modification for Biopolymer/Conjugated Polymer Hybrids as Renewable Energy Storage Materials.

    Science.gov (United States)

    Nilsson, Ting Yang; Wagner, Michal; Inganäs, Olle

    2015-12-07

    Lignin derivatives, which arise as waste products from the pulp and paper industry and are mainly used for heating, can be used as charge storage materials. The charge storage function is a result of the quinone groups formed in the lignin derivative. Herein, we modified lignins to enhance the density of such quinone groups by covalently linking monolignols and quinones through phenolation. The extra guaiacyl, syringyl, and hydroquinone groups introduced by phenolation of kraft lignin derivatives were monitored by (31) P nuclear magnetic resonance and size exclusion chromatography. Electropolymerization in ethylene glycol/tetraethylammonium tosylate electrolyte was used to synthesize the kraft lignin/polypyrrole hybrid films. These modifications changed the phenolic content of the kraft lignin with attachment of hydroquinone units yielding the highest specific capacity (around 70 mA h g(-1) ). The modification of softwood and hardwood lignin derivatives yielded 50 % and 23 % higher charge capacity than the original lignin, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Organic-inorganic hybrid thin film solar cells using conducting polymer and gold nanoparticles

    Science.gov (United States)

    Hwan Jung, Hyung; Ho Kim, Dong; Su Kim, Chang; Bae, Tae-Sung; Bum Chung, Kwun; Yoon Ryu, Seung

    2013-05-01

    We employed poly(styrenesulfonate)-doped poly (3,4-ethylenedioxythiophene) (PEDOT:PSS) as a p-layer on textured fluorine-tin-oxide (FTO) glass in pin-type hydrogenated amorphous silicon solar cells (a-Si:H SCs). An amorphous tungsten oxide (WO3) layer and gold nanoparticles (Au-NPs) 10 nm in size were included to prevent the degradation and to increase short-circuit current by the Plasmon effect, respectively, between the PEDOT:PSS and intrinsic-Si layer. The energy band between PEDOT:PSS and WO3 was meaningfully adjusted by Au-NPs. The p-type PEDOT:PSS layer in these organic-inorganic hybrid a-Si:H SCs results in an increased conversion efficiency from ˜2.42% to ˜5.49% and an increased open-circuit voltage from ˜0.29 V to ˜0.56 V. PEDOT:PSS on textured FTO glass is sufficiently showing that it can replace the p-type Si layer in pin-type a-Si:H SCs.

  8. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    International Nuclear Information System (INIS)

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik; Hundley, Angel; Vig, Komal; Singh, Shree Ram; Pillai, Shreekumar

    2010-01-01

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of ∼ 80 μm size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 μg demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 ± 6.72 mm, 19.4 ± 3.64 mm, 21.9 ± 4.33 mm, and 24.1 ± 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 ± 2.13 mm, 28.6 ± 4.27 mm, 22.6 ± 1.27 mm, and 27.0 ± 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 μg were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial strains tested. Further, the

  9. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    Energy Technology Data Exchange (ETDEWEB)

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik [Materials Science and Engineering, Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States); Hundley, Angel; Vig, Komal; Singh, Shree Ram; Pillai, Shreekumar, E-mail: rangariv@tuskegee.edu [Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL 36104 (United States)

    2010-03-05

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of {approx} 80 {mu}m size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 {mu}g demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 {+-} 6.72 mm, 19.4 {+-} 3.64 mm, 21.9 {+-} 4.33 mm, and 24.1 {+-} 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 {+-} 2.13 mm, 28.6 {+-} 4.27 mm, 22.6 {+-} 1.27 mm, and 27.0 {+-} 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 {mu}g were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial

  10. Synthesis of polymer hybrid latex poly(methyl methacrylate-co-butyl acrylate) with organo montmorillonite via miniemulsion polymerization method for barrier paper

    Science.gov (United States)

    Chanra, J.; Budianto, E.; Soegijono, B.

    2018-03-01

    Hybrid polymer latex based on combination of organic-inorganic materials, poly(methyl methacrylate-co-butyl acrylate) (PMMBA) and organo-montmorillonite (OMMT) were synthesized via miniemulsion polymerization technique. Modification of montmorillonite (MMT) through the incorporation of myristyltrimethylammonium bromide (MTAB) into the clay’s interlayer spaces were investigated by Small-Angle X-ray Scattering (SAXS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). Barrier property and thermal stability of polymer latex film sample were investigated through its Water Vapor Transmission Rate (WVTR) and Thermogravimetric Analysis (TGA). The results indicated that addition of OMMT as filler in PMMBA increased the barrier property and thermal stability of the latex film. Addition of 8.0% (wt) OMMT increased the barrier property and thermal stability. Miniemusion polymerization process with higher addition (>8.0 wt%) of OMMT resulting in high latex viscosity, particle size, and high amount of coagulum. The utilization of this hybrid polymer could benefits paper and board industries to produce high quality barrier paper for food packaging.

  11. Self-assembled hybrid materials based on conjugated polymers and semiconductors nano-crystals for plastic solar cells; Architectures hybrides auto-assemblees a base de systemes polyconjugues et de nanocristaux de semi-conducteurs pour le photovoltaique plastique

    Energy Technology Data Exchange (ETDEWEB)

    Girolamo, J. de

    2007-11-15

    This work is devoted to the elaboration of self-assembled hybrid materials based on poly(3- hexyl-thiophene) and CdSe nano-crystals for photovoltaic applications. For that, complementary molecular recognition units were introduced as side chain groups on the polymer and at the nano-crystals' surface. Diamino-pyrimidine groups were introduced by post-functionalization of a precursor copolymer, namely poly(3-hexyl-thiophene-co-3- bromo-hexyl-thiophene) whereas thymine groups were introduced at the nano-crystals' surface by a ligand exchange reaction with 1-(6-mercapto-hexyl)thymine. However, due to their different solubility, the mixing of the two components by solution processes is difficult. A 'one-pot' procedure was developed, but this method led to insoluble aggregates without control of the hybrid composition. To overcome the solubility problem, the layer-by-layer method was used to prepare the films. This method allows a precise control of the deposition process. Experimental parameters were tested in order to evaluate their impact on the resulting film. The films morphology was investigated by microscopy and X-Ray diffraction techniques. These analyses reveal an interpenetrated structure of nano-crystals within the polymer matrix rather than a multilayered structure. Electrochemical and spectro electrochemical studies were performed on the hybrid material deposited by the LBL process. Finally the materials were tested in a solar cell configuration and the I=f(V) curves reveals a clear photovoltaic behaviour. (author)

  12. Sulfur and Nitrogen co-doped graphene quantum dot decorated ZnO nanorod/polymer hybrid flexible device for photosensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Hmar, Jehova Jire L.; Majumder, Tanmoy; Dhar, Saurab; Mondal, Suvra Prakash, E-mail: suvraphy@gmail.com

    2016-08-01

    S and N co-doped graphene quantum dots (S,N-GQDs) have been synthesized by a hydrothermal process. S,N-GQDs are made up of 1–5 monolayer of graphene with average diameter 13.3 nm. The absorption peaks at 336 and 621 nm, are attributed to n → Π{sup ⁎} transitions of electrons in C=O and S=O bonds, respectively. S,N-GQDs are highly luminescent and showed excitation dependent emission behaviors. Hybrid photosensing device has been fabricated with S,N-GQD sensitized ZnO nanorods and a conjugated polymer poly(3-hexylthiophene) (P3HT). S,N-GQD decorated ZnO nanorod demonstrated higher photoresponse compared to pristine ZnO nanorod based device. S,N-GQD/ZnO nanorod hybrid device showed superior incident photon to electron conversion efficiency (IPCE), photoresponsivity and detectivity compared to the control samples. The flexibility study of the samples has been monitored by measuring current-voltage characteristics at different bending angles. - Highlights: • S and N co-doped graphene quantum dots (S,N-GQDs) were synthesized. • ZnO nanorods were grown on ITO coated flexible PET substrates. • S,N-GQDs were attached with ZnO nanorods and used as a green sensitizer. • Photosensing properties of S,N-GQD/ZnO and P3HT polymer hybrid device was studied.

  13. A hybrid molecularly imprinted polymer coated quantum dot nanocomposite optosensor for highly sensitive and selective determination of salbutamol in animal feeds and meat samples.

    Science.gov (United States)

    Raksawong, Phannika; Chullasat, Kochaporn; Nurerk, Piyaluk; Kanatharana, Proespichaya; Davis, Frank; Bunkoed, Opas

    2017-08-01

    A hybrid molecularly imprinted polymer (MIP)-coated quantum dot (QD) nanocomposite was synthesized and applied as a fluorescence probe for the highly sensitive and selective determination of salbutamol. The hybrid MIP-coated QD nanocomposite was synthesized via a copolymerization process in the presence of thioglycolic acid capped CdTe QDs with salbutamol as a template, 3-aminopropyltriethoxysilane as the functional monomer, and tetraethyl orthosilicate as a cross-linker. The optimum molar ratio of template, monomer, and cross-linker was 1:6:20. The fluorescence intensity of the hybrid MIP-coated QDs was efficiently quenched after salbutamol rebound to the recognition sites, as a result of charge transfer from QDs to salbutamol. The synthesized hybrid MIP-coated QD nanocomposite showed high sensitivity and good selectivity toward salbutamol. Under the optimal recognition conditions, the fluorescence intensity was quenched linearly with increasing concentration of salbutamol in the range from 0.10 to 25.0 μg L -1 , with a detection limit of 0.034 μg L -1 . The hybrid optosensor developed was successfully applied in the determination of salbutamol in animal feeds and meat samples. Satisfactory recoveries were obtained in the range from 85% to 98%, with a standard deviation of less than 8%. Furthermore, the accuracy of the hybrid MIP-coated QD nanocomposite was investigated by comparison with a conventional high-performance liquid chromatography method, with the results obtained with two methods agreeing well with each other. The advantages of this sensing method are simplicity, rapidity, cost-effectiveness, high sensitivity, and good selectivity. Graphical Abstract The synthesis of hybrid MIP-coated QDs nanocomposite.

  14. Schottky diodes between Bi2S3 nanorods and metal nanoparticles in a polymer matrix as hybrid bulk-heterojunction solar cells

    International Nuclear Information System (INIS)

    Saha, Sudip K.; Pal, Amlan J.

    2015-01-01

    We report the use of metal-semiconductor Schottky junctions in a conjugated polymer matrix as solar cells. The Schottky diodes, which were formed between Bi 2 S 3 nanorods and gold nanoparticles, efficiently dissociated photogenerated excitons. The bulk-heterojunction (BHJ) devices based on such metal-semiconductor Schottky diodes in a polymer matrix therefore acted as an efficient solar cell as compared to the devices based on only the semiconductor nanorods in the polymer matrix or when gold nanoparticles were added separately to the BHJs. In the latter device, gold nanoparticles offered plasmonic enhancement due to an increased cross-section of optical absorption. We report growth and characteristics of the Schottky junctions formed through an intimate contact between Bi 2 S 3 nanorods and gold nanoparticles. We also report fabrication and characterization of BHJ solar cells based on such heterojunctions. We highlight the benefit of using metal-semiconductor Schottky diodes over only inorganic semiconductor nanorods or quantum dots in a polymer matrix in forming hybrid BHJ solar cells

  15. Wireless Data Transmission at Terahertz Carrier Waves Generated from a Hybrid InP-Polymer Dual Tunable DBR Laser Photonic Integrated Circuit.

    Science.gov (United States)

    Carpintero, Guillermo; Hisatake, Shintaro; de Felipe, David; Guzman, Robinson; Nagatsuma, Tadao; Keil, Norbert

    2018-02-14

    We report for the first time the successful wavelength stabilization of two hybrid integrated InP/Polymer DBR lasers through optical injection. The two InP/Polymer DBR lasers are integrated into a photonic integrated circuit, providing an ideal source for millimeter and Terahertz wave generation by optical heterodyne technique. These lasers offer the widest tuning range of the carrier wave demonstrated to date up into the Terahertz range, about 20 nm (2.5 THz) on a single photonic integrated circuit. We demonstrate the application of this source to generate a carrier wave at 330 GHz to establish a wireless data transmission link at a data rate up to 18 Gbit/s. Using a coherent detection scheme we increase the sensitivity by more than 10 dB over direct detection.

  16. Growth of ZnSe nano-needles by pulsed laser deposition and their application in polymer/inorganic hybrid solar cells

    International Nuclear Information System (INIS)

    Chen, L.; Lai, J.S.; Fu, X.N.; Sun, J.; Ying, Z.F.; Wu, J.D.; Lu, H.; Xu, N.

    2013-01-01

    Using pulsed-laser deposition method, crystalline ZnSe nano-needles have been grown on catalyst-coated silicon (100) substrates. The crystalline ZnSe nano-needles with the middle diameters of about 20–80 nm, and the lengths ranging from 100 to 600 nm can be grown densely on 300–400 °C substrates. The as-grown ZnSe nano-needles were well crystalline and base-grown. They are potential electron-capturing materials in polymer/inorganic hybrid solar cells for their properties of good electron-conductance and high ratio surface area. Based on the ZnSe nano-needle cathode, a five-layer composite structure of polymer/inorganic hybrid solar cell has been designed and fabricated. The absorption spectra of the blend of regioregular poly(3-hexylthiophene-2,5-diyl) and phenyl-C61-butyric acid methyl ester (P3HT:PCBM), ZnSe nano-needles and the combination of P3HT:PCBM and ZnSe nano-needles were examined by ultraviolet–visible-infrared spectrophotometer, respectively. The absorption bands of the combination of P3HT:PCBM and ZnSe nano-needles fit well with the solar spectral distribution. - Highlights: ► Crystalline ZnSe nano-needles grown by pulsed laser deposition. ► A five-layer polymer/inorganic hybrid solar cell based on ZnSe nano-needles cathode. ► ZnSe nano-needles improve light absorption. ► Employment of ZnSe nano-needles increase the open-circuit voltage and fill factor

  17. iRGD-modified lipid–polymer hybrid nanoparticles loaded with isoliquiritigenin to enhance anti-breast cancer effect and tumor-targeting ability

    Directory of Open Access Journals (Sweden)

    Gao F

    2017-06-01

    Full Text Available Fei Gao,1–3 Jinming Zhang,3 Chaomei Fu,3 Xiaoming Xie,4 Fu Peng,1–3 Jieshu You,1,2 Hailin Tang,1,2,4 Zhiyu Wang,5 Peng Li,6 Jianping Chen1–3 1School of Chinese Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, 2Shenzhen Institute of Research and Innovation, University of Hong Kong, Shenzhen, 3College of Pharmacy, Chengdu University of Chinese Medicine, Chengdu, 4Department of Breast Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 5Department of Mammary Disease, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 6State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, People’s Republic of China Abstract: Isoliquiritigenin (ISL, a natural anti-breast cancer dietary compound, has poor delivery characteristics and low bioavailability. In order to promote the therapeutic outcome of ISL, a tumor-targeting lipid–polymer hybrid nanoparticle (NP system modified by tumor-homing iRGD peptides has been developed. The hybrid NPs were prepared by a modified single-step nanoprecipitation method to encapsulate ISL. iRGD peptides were anchored on the surface by a postinsertion method (ISL-iRGD NPs. The stable lipid–polymer structure of ISL-iRGD NPs, with high encapsulation and loading efficiency, was confirmed. Compared to free ISL and non-iRGD-modified counterparts, ISL-iRGD NPs showed higher cytotoxicity and cell apoptosis against the different type of breast cancer cells. This was attributable to higher cellular accumulation mediated by the iRGD-integrin recognition and the nanoscale effect. More importantly, based on the active tumor-tissue accumulation by iRGD peptides and the prolonged in vivo circulation by the stealth nanostructure, ISL-iRGD NPs displayed higher tumor-growth inhibition efficiency in 4T1-bearing breast-tumor mouse

  18. Silicon Nanowire/Polymer Hybrid Solar Cell-Supercapacitor: A Self-Charging Power Unit with a Total Efficiency of 10.5.

    Science.gov (United States)

    Liu, Ruiyuan; Wang, Jie; Sun, Teng; Wang, Mingjun; Wu, Changsheng; Zou, Haiyang; Song, Tao; Zhang, Xiaohong; Lee, Shuit-Tong; Wang, Zhong Lin; Sun, Baoquan

    2017-07-12

    An integrated self-charging power unit, combining a hybrid silicon nanowire/polymer heterojunction solar cell with a polypyrrole-based supercapacitor, has been demonstrated to simultaneously harvest solar energy and store it. By efficiency enhancement of the hybrid nanowire solar cells and a dual-functional titanium film serving as conjunct electrode of the solar cell and supercapacitor, the integrated system is able to yield a total photoelectric conversion to storage efficiency of 10.5%, which is the record value in all the integrated solar energy conversion and storage system. This system may not only serve as a buffer that diminishes the solar power fluctuations from light intensity, but also pave its way toward cost-effective high efficiency self-charging power unit. Finally, an integrated device based on ultrathin Si substrate is demonstrated to expand its feasibility and potential application in flexible energy conversion and storage devices.

  19. Preparation of polymer nanocomposites with enhanced mechanical properties using hybrid of graphene and partially wrapped multi-wall carbon nanotube as nanofiller

    Institute of Scientific and Technical Information of China (English)

    Jiao You; Jiang-Yong-Quan Cao; Si-Chong Chen; Yu-Zhong Wang

    2017-01-01

    Triblock copolymer of poly(p-dioxanone) and polyethylene glycol end-capped with pyrene moieties ((Py-PPDO)2-b-PEG) was synthesized and used as modifier for multi-wall carbon nanotubes (MWCNTs).Nano-aggregates ((Py-PPDO)2-b-PEG@NWCNTs) with shish-kebab like partially wrapped morphology and very good stability were obtained by incorporating the copolymer with MWCNTs.The bare MWCNT sections of (Py-PPDO)2-b-PEG@MWCNTs were able to induce π-π interactions with graphene (GE) and resulted in a novel GE/(Py-PPDO)2-b-PEG@MWCNTs hybrid.The dispersity of GE in solution or polymer matrix was therefore greatly improved.The PCL nanocomposite films using GE/(Py-PPDO)2-b-PEG@MWCNTs as hybrid nanofiller exhibited obviously improved mechanical properties especially at very low hybrid nanofiller content.The influence of the nanofiller content and feed ratio of GE/ MWCNTs on the mechanical properties of composites films was evaluated.When the feed ratio of GE to MWCNTs is 2:8 and the total loading of nanofiller is only 0.01 wt%,the tensile strength of the composite film increased by 163% and the elongation at break increased by 17% compared to those of neat PCL These results can be attributed to fine dispersion of the nanofillers in PCL matrix and the hybrid interactions between GE and MWCNTs.Therefore,this work provides a novel method for preparing polymer nanocomposites with high mechanical performance and low nanofiller loading.

  20. Controllable Synthesis of Gold Nanorod/Conducting Polymer Core/Shell Hybrids Toward in Vitro and in Vivo near-Infrared Photothermal Therapy.

    Science.gov (United States)

    Wang, Juan; Zhu, Chunhua; Han, Jie; Han, Na; Xi, Juqun; Fan, Lei; Guo, Rong

    2018-04-18

    Photothermal therapy (PTT) is a minimally invasive tumor treatment technology, and is regarded as a potential anticancer strategy because of its targeted destruction and low toxicity. Specifically, near-infrared light-induced PTT has attracted intriguing interest because of the high transparency of tissue, blood, and water. However, effective PTT generally requires the assistance of photothermal agents. Gold nanorods (GNRs) and conducting polymer are often used as photothermal materials because of their high absorption efficiency and photothermal conversion efficiency. Herein, we combined GNRs with poly( o-methoxyaniline) (POMA, a polyaniline derivative) to form GNRs/POMA core/shell hybrids through the surfactant-assisted chemical oxidative polymerization route and studied their photothermal conversion properties. The configuration of GNRs/POMA core/shell hybrids has been precisely controlled through adjusting the monomer concentration, and the relationship between morphology and absorption band of GNRs/POMA core/shell hybrids has been revealed. Finally, the in vitro and in vivo experiments were performed, and the results indicated that the GNRs/POMA core/shell hybrids with optimized absorbance at around 808 nm exhibited the best performance on photothermal therapy under 808 nm NIR laser irradiation.

  1. A three-dimensional transient mixed hybrid finite element model for superabsorbent polymers with strain-dependent permeability

    NARCIS (Netherlands)

    Yu, Cong; Malakpoor, Kamyar; Huyghe, Jacques M.

    2018-01-01

    A hydrogel is a cross-linked polymer network with water as solvent. Industrially widely used superabsorbent polymers (SAP) are partially neutralized sodium polyacrylate hydrogels. The extremely large degree of swelling is one of the most distinctive characteristics of such hydrogels, as the volume

  2. Immunoradiotherapeutically hybrid polymer system

    International Nuclear Information System (INIS)

    Loukotova, L.; Kucka, J.; Hruby, M.; Rabyk, M.; Francova, P.; Kolarova, V.; Paral, P.; Heizer, T.; Sefc, L.

    2017-01-01

    Thermoresponsive copolymer of β-glucan-graft poly(2-alkyl-2-oxazoline) carrying a fluorescent dye Dy615 and a chelating group (DOTA) was radiolabelled with 90 Y and injected into the tumor of experimental animals (female mice of the strain C57BL/6 bearing tumor line EL4). Was monitored by tumor size, weight, and survival of the experimental animals and their blood picture. Cured was 46 % of the experimental animals. (authors)

  3. Fatigue strength of a hybrid joint formed between a PA6-GF60 polymer matrix and a S420MC steel insert

    International Nuclear Information System (INIS)

    Miklavec, M.; Klemenc, J.; Kostanjevec, A.; Fajdiga, M.

    2013-01-01

    Highlights: • Presented is an innovative polymer-metal hybrid joint. • Durability curves and their scatter were calculated using the DASA procedure. • Specimens with the embossed steel insert outperformed in static and dynamic tests. - Abstract: A vehicle’s brake pedal is considered to be one of its most important safety components. In the past, vehicle weight-reduction initiatives resulted in a highly optimized design of steel brake pedal with an increased strength-to-weight ratio. However, any further reduction in the weight of the brake pedal is only possible by using combined, i.e., hybrid, materials. In this case the joint between the two different materials in the hybrid arrangement must be as strong as possible. Many methods for improving the joint between two highly dissimilar materials are known from the literature, but conventional joining techniques lack either the fatigue resistance, because of a poor notch-effect design (shape-based joints), or are unsuitable for low-cost serial production (material-based joints). This article presents an innovative approach to joining the reinforcing insert with a glass-fiber-reinforced polyamide 6 (PA6-GF) base structure, where the reinforcing insert is molded into the PA6-GF. The improved shape of the reinforcing insert contributes the required strength, while the PA6-GF base structure provides the final form of the specimen/product. The innovative shape of the metal insert not only provides the strength of the component; it also ensures the proper joint between the two dissimilar materials. For different types of reinforcing inserts static durability tests as well as fatigue-life tests of the insert-PA6-GF-matrix joints were performed. Our experimental research shows that the most promising shape-based hybrid joints reported in the literature are not the best solution when the hybrid joint’s fatigue life is the decisive criterion for a product’s durability

  4. Preparation and in vitro evaluation of folate-receptor-targeted SPION-polymer micelle hybrids for MRI contrast enhancement in cancer imaging

    Science.gov (United States)

    Mahajan, Shveta; Koul, Veena; Choudhary, Veena; Shishodia, Gauri; Bharti, Alok C.

    2013-01-01

    Polymer-SPION hybrids were investigated for receptor-mediated localization in tumour tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared by high-temperature decomposition of iron acetylacetonate were monodisperse (9.27 ± 3.37 nm), with high saturation magnetization of 76.8 emu g-1. Amphiphilic copolymers prepared from methyl methacrylate and PEG methacrylate by atom transfer radical polymerization were conjugated with folic acid (for folate-receptor specificity). The folate-conjugated polymer had a low critical micellar concentration (0.4 mg l-1), indicating stability of the micellar formulation. SPION-polymeric micelle clusters were prepared by desolvation of the SPION dispersion/polymer solution in water. Magnetic resonance imaging of the formulation revealed very good contrast enhancement, with transverse (T2) relaxivity of 260.4 mM-1 s-1. The biological evaluation of the SPION micelles included cellular viability assay (MTT) and uptake in HeLa cells. These studies demonstrated the potential use of these nanoplatforms for imaging and targeting.

  5. Hybrid active layers from a conjugated polymer and inorganic nanoparticles for organic light emitting devices with emission colour tuned by electric field

    Energy Technology Data Exchange (ETDEWEB)

    Aleshin, Andrey N; Alexandrova, Elena L; Shcherbakov, Igor P [Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 26, Polytechnicheskaya Str., St Petersburg 194021 (Russian Federation)], E-mail: aleshin@transport.ioffe.ru

    2009-05-21

    We report on the investigation of the electrical and optical properties of hybrid active layers for organic devices consisting of a conjugated polymer MEH-PPV mixed with ZnO and Si nanoparticles. The effect of an electric field on the photoluminescence (PL) from a MEH-PPV : ZnO composite film is studied. We have found that in the absence of an electric field PL emission from the MEH-PPV : ZnO composites have two main maxima in the blue-red regions. Three additional minor PL maxima attributed to the exciplex states were found at {approx}420-480 nm. Application of a voltage bias to planar electrodes significantly suppresses the blue emission. Generation of excited states in the MEH-PPV : ZnO structures implies the presence of several radiative recombination mechanisms with the formation of polymer-nanoparticle complexes including exciplex states and charge transfer between the polymer and nanoparticles that can be controlled by an electric field. This effect provides the possibility to tune by an electric field the emission colour of organic light emitting diodes by combining an efficient emission from both organic/inorganic materials involved.

  6. Hybrid active layers from a conjugated polymer and inorganic nanoparticles for organic light emitting devices with emission colour tuned by electric field

    International Nuclear Information System (INIS)

    Aleshin, Andrey N; Alexandrova, Elena L; Shcherbakov, Igor P

    2009-01-01

    We report on the investigation of the electrical and optical properties of hybrid active layers for organic devices consisting of a conjugated polymer MEH-PPV mixed with ZnO and Si nanoparticles. The effect of an electric field on the photoluminescence (PL) from a MEH-PPV : ZnO composite film is studied. We have found that in the absence of an electric field PL emission from the MEH-PPV : ZnO composites have two main maxima in the blue-red regions. Three additional minor PL maxima attributed to the exciplex states were found at ∼420-480 nm. Application of a voltage bias to planar electrodes significantly suppresses the blue emission. Generation of excited states in the MEH-PPV : ZnO structures implies the presence of several radiative recombination mechanisms with the formation of polymer-nanoparticle complexes including exciplex states and charge transfer between the polymer and nanoparticles that can be controlled by an electric field. This effect provides the possibility to tune by an electric field the emission colour of organic light emitting diodes by combining an efficient emission from both organic/inorganic materials involved.

  7. Synthesis and characterization of hybrid carbon nanotube/polymer for use in the active layer of organic solar cells'

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Luiza De Lazari; Calado, Hallen Daniel Rezende, E-mail: luizadl@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2016-07-01

    Full text: Nowadays, the fast development of portable and flexible devices such as smart phones, smart watches and adhesive sensors, has stimulated research into alternative energy generators for the operation of these devices. Organic solar cells (OPVs) are seen as a promising technology in this scenario because their properties such as low weight, semi-transparency, low cost and flexibility. Intrinsically conducting polymers (CPs) are studied as active layer in OPVs because their good electrical and optical properties. The carbon nanotube - CNT in the polymer matrix leads to the formation of interconnected nano networks influencing the crystalline CP behavior and reducing the resistance in the charge transfer. This increases the transport of electrons and minimizes recombination by p-p and p-CH{sub 2} interaction with CPs, enhancing its properties and improving the efficiency of OPVs optoelectronics. To preparing the hybrid for this work in 3 stages it was used a homemade multi-walled CNT. Initially, the CNT's were functionalized with amine 1,3-diaminopropane - DAP (CNT-DAP) and then with an amine monomer from p-aminobenzoic acid - ABA. In a subsequent step, the hybrid (CNT-DAP-ABA-P3HT) was obtained by polymerizing using FeCl{sub 3} 3- hexylthiophene (3HT) in the presence of NTC-DAP-ABA, which led to obtaining the PC directly connected to CNT. The resulting hybrid was characterized by FTIR, Raman, XPS, thermal analysis, SEM, optical absorption and fluorescence. FTIR spectra showed bands associated with functional groups present in the functionalization steps. Raman results showed the increase of the ratio ID/IG caused by greater disorder by inserting the new groups to the CNT. The electrochemical profile was studied by cyclic voltammetry at different scan rates, generating curves with almost reversible profile. The analyzes showed that the CNT were functionalized covalently and have potential for application in active layer of OPVs. (author)

  8. Radiation Synthesis and Characterization of Natural and Natural-Synthetic Hybrid Super Absorbent Polymers for Agricultural Applications. Chapter 19

    Energy Technology Data Exchange (ETDEWEB)

    Şen, M.; Hayrabolulu, H.; Güven, O. [Hacettepe University Department of Chemistry, Beytepe, Ankara (Turkey)

    2014-07-15

    The experimental studies carried out in Hacettepe University, Laboratories of Radiation and Polymers Science (LRPS) in the past ten years, which focused mainly on the synthesis of synthetic and natural-synthetic super absorbent polymers in various irradiation conditions, are summarized in the first part of the presentation. Studies conducted on the following areas: (1) the controlled release of fertilizers and herbicides and the effect of the natural polymer type, (2) the neutralization degree of poly(acrylic acid), (3) the temperature and pressure on the swelling kinetics, and (4) the maximum water absorption capacity of the potential soil conditional hydrogels, were explained. The results were then compared with those obtained from commercial super absorbent polymers prepared through conventional techniques. In the third part of the presentation, basic and advanced techniques in the characterization of the network structure of super water absorbents were presented. (author)

  9. Optimization of hybrid polymer electrolytes with the effect of lithium salt concentration in PEO/PVdF-HFP blends

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepa, P.; Edwin raj, S.; Sowmya, G.; Kalaiselvimary, J.; Ramesh Prabhu, M., E-mail: mkram83@gmail.com

    2016-03-15

    Highlights: • Polymer blends based on PVdF-HFP/PEO were prepared for Li-ion battery applications. • Structural and electrochemical studies were carried out on prepared electrolytes. • The electrolytes can be used as electrolyte in the possible device fabrications. - Abstract: Poly(ethylene oxide) (PEO) 6.25 wt%/poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HFP)] 18.75 wt% blend based electrolyte films containing different concentrations (2–10) wt% of lithium salt were prepared. The miscibility studies have been performed by using X-ray diffraction and Fourier transform infrared spectroscopy. The role of interaction between polymer hosts on conductivity is discussed using the results of a.c. impedance studies. A room temperature conductivity of 2.3912 × 10{sup −4} S cm{sup −1} has been obtained for PEO (6.25)–PVdF-HFP (18.75)–LiClO{sub 4} (8)–PC (67) polymer complex. The temperature dependence of the conductivity of polymer electrolyte seems to obey VTF relation. Electrochemical stability (3.3 V) was observed in the prepared polymer electrolyte. Reduction process and oxidation process of the prepared electrolyte system have also been evaluated by means of cyclic voltammetry. Thermogravimetric analysis results indicate thermal stability of PEO/PVdF-HFP lithium salt complexes. Roughness parameter of the sample having maximum ionic conductivity was studied by AFM. The morphology of the polymer complex is investigated by using SEM.

  10. Polymer/metal oxide hybrid dielectrics for low voltage field-effect transistors with solution-processed, high-mobility semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Held, Martin; Schießl, Stefan P.; Gannott, Florentina [Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen D-91058 (Germany); Institute for Physical Chemistry, Universität Heidelberg, Heidelberg D-69120 (Germany); Miehler, Dominik [Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen D-91058 (Germany); Zaumseil, Jana, E-mail: zaumseil@uni-heidelberg.de [Institute for Physical Chemistry, Universität Heidelberg, Heidelberg D-69120 (Germany)

    2015-08-24

    Transistors for future flexible organic light-emitting diode (OLED) display backplanes should operate at low voltages and be able to sustain high currents over long times without degradation. Hence, high capacitance dielectrics with low surface trap densities are required that are compatible with solution-processable high-mobility semiconductors. Here, we combine poly(methyl methacrylate) (PMMA) and atomic layer deposition hafnium oxide (HfO{sub x}) into a bilayer hybrid dielectric for field-effect transistors with a donor-acceptor polymer (DPPT-TT) or single-walled carbon nanotubes (SWNTs) as the semiconductor and demonstrate substantially improved device performances for both. The ultra-thin PMMA layer ensures a low density of trap states at the semiconductor-dielectric interface while the metal oxide layer provides high capacitance, low gate leakage and superior barrier properties. Transistors with these thin (≤70 nm), high capacitance (100–300 nF/cm{sup 2}) hybrid dielectrics enable low operating voltages (<5 V), balanced charge carrier mobilities and low threshold voltages. Moreover, the hybrid layers substantially improve the bias stress stability of the transistors compared to those with pure PMMA and HfO{sub x} dielectrics.

  11. Comparative analysis of poly-glycolic acid-based hybrid polymer starter matrices for in vitro tissue engineering.

    Science.gov (United States)

    Generali, Melanie; Kehl, Debora; Capulli, Andrew K; Parker, Kevin K; Hoerstrup, Simon P; Weber, Benedikt

    2017-10-01

    Biodegradable scaffold matrixes form the basis of any in vitro tissue engineering approach by acting as a temporary matrix for cell proliferation and extracellular matrix deposition until the scaffold is replaced by neo-tissue. In this context several synthetic polymers have been investigated, however a concise systematic comparative analyses is missing. Therefore, the present study systematically compares three frequently used polymers for the in vitro engineering of extracellular matrix based on poly-glycolic acid (PGA) under static as well as dynamic conditions. Ultra-structural analysis was used to examine the polymers structure. For tissue engineering (TE) three human fibroblast cell lines were seeded on either PGA-poly-4-hydroxybutyrate (P4HB), PGA-poly-lactic acid (PLA) or PGA-poly-caprolactone (PCL) patches. These patches were analyzed after 21days of culture qualitative by histology and quantitative by determining the amount of DNA, glycosaminoglycan and hydroxyproline. We found that PGA-P4HB and PGA-PLA scaffolds enhance tissue formation significantly higher than PGA-PCL scaffolds (p<0.05). Polymer remnants were visualized by polarization microscopy. In addition, biomechanical properties of the tissue engineered patches were determined in comparison to native tissue. This study may allow future studies to specifically select certain polymer starter matrices aiming at specific tissue properties of the bioengineered constructs in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Gel electrolytes based on poly(acrylonitrile)/sulpholane with hybrid TiO2/SiO2 filler for advanced lithium polymer batteries

    International Nuclear Information System (INIS)

    Kurc, Beata

    2014-01-01

    Highlights: • Paper describes properties of gel electrolyte based on PAN with TMS and TiO 2 -SiO 2 . • The TiO 2 -SiO 2 oxide composite was precipitated in the emulsion system and used as the fillers. • The capacity of the graphite anode depends on the current rate and the amount of TiO 2 -SiO 2 . • For PE3 electrolyte was obtained practical capacity more than 90% of the theoretical capacity. - Abstract: This paper describes the synthesis and properties of a new type of ceramic fillers for composite polymer gel electrolytes. Hybrid TiO 2 -SiO 2 ceramic powders have been obtained by co-precipitation from titanium(IV) sulfate solution using sodium silicate as the precipitating agent. The resulting submicron-size powders have been applied as fillers for composite polymer gel electrolytes for Li-ion batteries based on polyacrylonitrile (PAN) membranes. The powders and gel electrolytes have been examined structurally and electrochemically, showing favorable properties in terms of electrolyte uptake and electrochemical characteristics in Li-ion cells

  13. Fabrication of white light-emitting diodes based on UV light-emitting diodes with conjugated polymers-(CdSe/ZnS) quantum dots as hybrid phosphors.

    Science.gov (United States)

    Jung, Hyunchul; Chung, Wonkeun; Lee, Chang Hun; Kim, Sung Hyun

    2012-07-01

    White light-emitting diodes (LEDs) were fabricated using GaN-based 380-nm UV LEDs precoated with the composite of blue-emitting polymer (poly[(9,9-dihexylfluorenyl-2,7-diyl)-alt-co-(2-methoxy-5-{2-ethylhexyloxy)-1 ,4-phenylene)]), yellow green-emitting polymer (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3}-thiadiazole)]), and 605-nm red-emitting quantum dots (QDs). CdSe cores were obtained by solvothermal route using CdO, Se precursors and ZnS shells were synthesized by using diethylzinc, and hexamethyldisilathiane precursors. The optical properties of CdSe/ZnS QDs were characterized by UV-visible and photoluminescence (PL) spectra. The structural data and composition of the QDs were transmission electron microscopy (TEM), and EDX technique. The quantum yield and size of the QDs were 58.7% and about 6.7 nm, respectively. Three-band white light was generated by hybridizing blue (430 nm), green (535 nm), and red (605 nm) emission. The color-rendering index (CRI) of the device was extremely improved by introducing the QDs. The CIE-1931 chromaticity coordinate, color temperature, and CRI of a white LED at 20 mA were (0.379, 0.368), 3969 K, and 90, respectively.

  14. Preparation and in vitro evaluation of folate-receptor-targeted SPION–polymer micelle hybrids for MRI contrast enhancement in cancer imaging

    International Nuclear Information System (INIS)

    Mahajan, Shveta; Choudhary, Veena; Koul, Veena; Shishodia, Gauri; Bharti, Alok C

    2013-01-01

    Polymer–SPION hybrids were investigated for receptor-mediated localization in tumour tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared by high-temperature decomposition of iron acetylacetonate were monodisperse (9.27 ± 3.37 nm), with high saturation magnetization of 76.8 emu g −1 . Amphiphilic copolymers prepared from methyl methacrylate and PEG methacrylate by atom transfer radical polymerization were conjugated with folic acid (for folate-receptor specificity). The folate-conjugated polymer had a low critical micellar concentration (0.4 mg l −1 ), indicating stability of the micellar formulation. SPION–polymeric micelle clusters were prepared by desolvation of the SPION dispersion/polymer solution in water. Magnetic resonance imaging of the formulation revealed very good contrast enhancement, with transverse (T 2 ) relaxivity of 260.4 mM −1 s −1 . The biological evaluation of the SPION micelles included cellular viability assay (MTT) and uptake in HeLa cells. These studies demonstrated the potential use of these nanoplatforms for imaging and targeting. (paper)

  15. Micromechanical analysis of a hybrid composite—effect of boron carbide particles on the elastic properties of basalt fiber reinforced polymer composite

    Science.gov (United States)

    Krishna Golla, Sai; Prasanthi, P.

    2016-11-01

    A fiber reinforced polymer (FRP) composite is an important material for structural application. The diversified application of FRP composites has become the center of attention for interdisciplinary research. However, improvements in the mechanical properties of this class of materials are still under research for different applications. The reinforcement of inorganic particles in a composite improves its structural properties due to their high stiffness. The present research work is focused on the prediction of the mechanical properties of the hybrid composites where continuous fibers are reinforced in a micro boron carbide particle mixed polypropylene matrix. The effectiveness of the addition of 30 wt. % of boron carbide (B4C) particle contributions regarding the longitudinal and transverse properties of the basalt fiber reinforced polymer composite at various fiber volume fractions is examined by finite element analysis (FEA). The experimental approach is the best way to determine the properties of the composite but it is expensive and time-consuming. Therefore, the finite element method (FEM) and analytical methods are the viable methods for the determination of the composite properties. The FEM results were obtained by adopting a micromechanics approach with the support of FEM. Assuming a uniform distribution of reinforcement and considering one unit-cell of the whole array, the properties of the composite materials are determined. The predicted elastic properties from FEA are compared with the analytical results. The results suggest that B4C particles are a good reinforcement for the enhancement of the transverse properties of basalt fiber reinforced polypropylene.

  16. The Specific Refractive Index Increments for POSS Polymers in Solution

    National Research Council Canada - National Science Library

    Largo, Sheryl

    2004-01-01

    Partial contents: Hybrid Inorganic/Organic Polymers, Introduction to POSS, Anatomy of a POSS Nanostructure, POSS Polymer Incorporation, POSS Styrene Monomer Synthesis, POSS Styrene Copolymer Synthesis, 1HNMR...

  17. Enhanced performance of P(VDF-HFP)-based composite polymer electrolytes doped with organic-inorganic hybrid particles PMMA-ZrO2 for lithium ion batteries

    Science.gov (United States)

    Xiao, Wei; Wang, Zhiyan; Zhang, Yan; Fang, Rui; Yuan, Zun; Miao, Chang; Yan, Xuemin; Jiang, Yu

    2018-04-01

    To improve the ionic conductivity as well as enhance the mechanical strength of the gel polymer electrolyte, poly(vinylidene fluoride-hexafluoroprolene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with the organic-inorganic hybrid particles poly(methyl methacrylate) -ZrO2 (PMMA-ZrO2) are prepared by phase inversion method, in which PMMA is successfully grafted onto the surface of the homemade nano-ZrO2 particles via in situ polymerization confirmed by FT-IR. XRD and DSC patterns show adding PMMA-ZrO2 particles into P(VDF-HFP) can significantly decrease the crystallinity of the CPE membrane. The CPE membrane doped with 5 wt % PMMA-ZrO2 particles can not only present a homogeneous surface with abundant interconnected micro-pores, but maintain its initial shape after thermal exposure at 160 °C for 1 h, in which the ionic conductivity and lithium ion transference number at room temperature can reach to 3.59 × 10-3 S cm-1 and 0.41, respectively. The fitting results of the EIS plots indicate the doped PMMA-ZrO2 particles can significantly lower the interface resistance and promote lithium ions diffusion rate. The Li/CPE-sPZ/LiCoO2 and Li/CPE-sPZ/Graphite coin cells can deliver excellent rate and cycling performance. Those results suggest the P(VDF-HFP)-based CPE doped with 5 wt % PMMA-ZrO2 particles can become an exciting potential candidate as polymer electrolyte for the lithium ion battery.

  18. Ultra-tough and strong, hybrid thin films based on ionically crosslinked polymers and 2D inorganic platelets

    Science.gov (United States)

    Ji, Dong Hwan; Choi, Suji; Kim, Jaeyun; nanobiomaterials lab Team

    Integration of high strength and toughness tend to be mutually exclusive and synthesized hybrid films with superior mechanical properties have been difficult to fabricate controllable shapes and various scales. Although diverse synthesized hybrid films consisting of organic matrix and inorganic materials with brick-and-mortar structure, show improved mechanical properties, these films are still limited in toughness and fabrication methods. Herein, we report ultra-tough and strong hybrid thin films with self-assembled uniform microstructures with controllable shapes and various scale based on hydrogel-mediated process. Ca2+-crosslinking in alginate chains and well-aligned alumina platelets in alginate matrix lead to a synergistic enhancement of strength and toughness in the resulting film. Consequentially, Ca2+-crosslinked Alg/Alu films showed outstanding toughness of 29 MJ m-3 and tensile strength of 160 MPa. Furthermore, modifying Alu surface with polyvinylpyrrolidone (PVP), tensile strength was further improved up to 200 MPa. Our results suggest an alternative approach to design and processing of self-assembled hydrogel-mediated hybrid films with outstanding mechanical properties.

  19. Modular bioink for 3D printing of biocompatible hydrogels : sol-gel polymerization of hybrid peptides and polymers

    NARCIS (Netherlands)

    Echalier, C.; Levato, R.; Mateos-Timoneda, Miguel A; Castaño, O.; Déjean, S.; Garric, X.; Pinese, C.; Noël, D.; Engel, E.; Martinez, J.; Mehdi, A.; Subra, G.

    2017-01-01

    An unprecedented generic system allowing the 3D printing of peptide-functionalized hydrogels by soft sol-gel inorganic polymerization is presented. Hybrid silylated inorganic/bioorganic blocks are mixed in biological buffer in an appropriate ratio, to yield a multicomponent bioink that can be

  20. A randomized multicenter comparison of hybrid sirolimus-eluting stents with bioresorbable polymer versus everolimus-eluting stents with durable polymer in total coronary occlusion: rationale and design of the Primary Stenting of Occluded Native Coronary Arteries IV study

    Directory of Open Access Journals (Sweden)

    Teeuwen Koen

    2012-12-01

    Full Text Available Abstract Background Percutaneous recanalization of total coronary occlusion (TCO was historically hampered by high rates of restenosis and reocclusions. The PRISON II trial demonstrated a significant restenosis reduction in patients treated with sirolimus-eluting stents compared with bare metal stents for TCO. Similar reductions in restenosis were observed with the second-generation zotarolimus-eluting stent and everolimus-eluting stent. Despite favorable anti-restenotic efficacy, safety concerns evolved after identifying an increased rate of very late stent thrombosis (VLST with drug-eluting stents (DES for the treatment of TCO. Late malapposition caused by hypersensitivity reactions and chronic inflammation was suggested as a probable cause of these VLST. New DES with bioresorbable polymer coatings were developed to address these safety concerns. No randomized trials have evaluated the efficacy and safety of the new-generation DES with bioresorbable polymers in patients treated for TCO. Methods/Design The prospective, randomized, single-blinded, multicenter, non-inferiority PRISON IV trial was designed to evaluate the safety, efficacy, and angiographic outcome of hybrid sirolimus-eluting stents with bioresorbable polymers (Orsiro; Biotronik, Berlin, Germany compared with everolimus-eluting stents with durable polymers (Xience Prime/Xpedition; Abbott Vascular, Santa Clara, CA, USA in patients with successfully recanalized TCOs. In total, 330 patients have been randomly allocated to each treatment arm. Patients are eligible with estimated duration of TCO ≥4 weeks with evidence of ischemia in the supply area of the TCO. The primary endpoint is in-segment late luminal loss at 9-month follow-up angiography. Secondary angiographic endpoints include in-stent late luminal loss, minimal luminal diameter, percentage of diameter stenosis, in-stent and in-segment binary restenosis and reocclusions at 9-month follow-up. Additionally, optical coherence

  1. Silver Nanowire/MnO2 Nanowire Hybrid Polymer Nanocomposites: Materials with High Dielectric Permittivity and Low Dielectric Loss.

    Science.gov (United States)

    Zeraati, Ali Shayesteh; Arjmand, Mohammad; Sundararaj, Uttandaraman

    2017-04-26

    This study reports the fabrication of hybrid nanocomposites based on silver nanowire/manganese dioxide nanowire/poly(methyl methacrylate) (AgNW/MnO 2 NW/PMMA), using a solution casting technique, with outstanding dielectric permittivity and low dielectric loss. AgNW was synthesized using the hard-template technique, and MnO 2 NW was synthesized employing a hydrothermal method. The prepared AgNW:MnO 2 NW (2.0:1.0 vol %) hybrid nanocomposite showed a high dielectric permittivity (64 at 8.2 GHz) and low dielectric loss (0.31 at 8.2 GHz), which are among the best reported values in the literature in the X-band frequency range (8.2-12.4 GHz). The superior dielectric properties of the hybrid nanocomposites were attributed to (i) dimensionality match between the nanofillers, which increased their synergy, (ii) better dispersion state of AgNW in the presence of MnO 2 NW, (iii) positioning of ferroelectric MnO 2 NW in between AgNWs, which increased the dielectric permittivity of nanodielectrics, thereby increasing dielectric permittivity of the hybrid nanocomposites, (iv) barrier role of MnO 2 NW, i.e., cutting off the contact spots of AgNWs and leading to lower dielectric loss, and (v) AgNW aligned structure, which increased the effective surface area of AgNWs, as nanoelectrodes. Comparison of the dielectric properties of the developed hybrid nanocomposites with the literature highlights their great potential for flexible capacitors.

  2. Bio-inspired Construction of Advanced Fuel Cell Cathode with Pt Anchored in Ordered Hybrid Polymer Matrix

    OpenAIRE

    Xia, Zhangxun; Wang, Suli; Jiang, Luhua; Sun, Hai; Liu, Shuang; Fu, Xudong; Zhang, Bingsen; Sheng Su, Dang; Wang, Jianqiang; Sun, Gongquan

    2015-01-01

    The significant use of platinum for catalyzing the cathodic oxygen reduction reactions (ORRs) has hampered the widespread use of polymer electrolyte membrane fuel cells (PEMFCs). The construction of well-defined electrode architecture in nanoscale with enhanced utilization and catalytic performance of Pt might be a promising approach to address such barrier. Inspired by the highly efficient catalytic processes in enzymes with active centers embedded in charge transport pathways, here we demon...

  3. Hybrid polymer-CdS solar cell active layers formed by in situ growth of CdS nanoparticles

    International Nuclear Information System (INIS)

    Masala, S.; Del Gobbo, S.; Borriello, C.; Bizzarro, V.; La Ferrara, V.; Re, M.; Pesce, E.; Minarini, C.; De Crescenzi, M.; Di Luccio, T.

    2011-01-01

    The integration of semiconductor nanoparticles (NPs) into a polymeric matrix has the potential to enhance the performance of polymer-based solar cells taking advantage of the physical properties of NPs and polymers. We synthesize a new class of CdS-NPs-based active layer employing a low-cost and low temperature route compatible with large-scale device manufacturing. Our approach is based on the controlled in situ thermal decomposition of a cadmium thiolate precursor in poly(3-hexylthiophene) (P3HT). The casted P3HT:precursor solid foils were heated up from 200 to 300 °C to allow the precursor decomposition and the CdS-NP formation within the polymer matrix. The CdS-NP growth was controlled by varying the annealing temperature. The polymer:precursor weight ratio was also varied to investigate the effects of increasing the NP volume fraction on the solar cell performances. The optical properties were studied by using UV–Vis absorption and photoluminescence (PL) spectroscopy at room temperature. To investigate the photocurrent response of P3HT:CdS nanocomposites, ITO/P3HT:CdS/Al solar cell devices were realized. We measured the external quantum efficiency (EQE) as a function of the wavelength. The photovoltaic response of the devices containing CdS-NPs showed a variation compared with the devices with P3HT only. By changing the annealing temperature the EQE is enhanced in the 400–600 nm spectral region. By increasing the NPs volume fraction remarkable changes in the EQE spectra were observed. The data are discussed also in relation to morphological features of the interfaces studied by Focused Ion Beam technique.

  4. Chemical resistance, void content and tensile properties of oil palm/jute fibre reinforced polymer hybrid composites

    International Nuclear Information System (INIS)

    Jawaid, M.; Khalil, H.P.S. Abdul; Bakar, A. Abu; Khanam, P. Noorunnisa

    2011-01-01

    Tri layer hybrid composites of oil palm empty fruit bunches (EFB) and jute fibres was prepared by keeping oil palm EFB as skin material and jute as the core material and vice versa. The chemical resistance, void content and tensile properties of oil palm EFB/Jute composites was investigated with reference to the relative weight of oil palm EFB/Jute, i.e. 4:1, the fibre loading was optimized and different layering pattern were investigated. It is found from the chemical resistance test that all the composites are resistant to various chemicals. It was observed that marked reduction in void content of hybrid composites in different layering pattern. From the different layering pattern, the tensile properties were slightly higher for the composite having jute as skin and oil palm EFB as core material. Scanning electron microscopy (SEM) was used to study tensile fracture surfaces of different composites.

  5. Design of water-repellant coating using dual scale size of hybrid silica nanoparticles on polymer surface

    Science.gov (United States)

    Conti, J.; De Coninck, J.; Ghazzal, M. N.

    2018-04-01

    The dual-scale size of the silica nanoparticles is commonly aimed at producing dual-scale roughness, also called hierarchical roughness (Lotus effect). In this study, we describe a method to build a stable water-repellant coating with controlled roughness. Hybrid silica nanoparticles are self-assembled over a polymeric surface by alternating consecutive layers. Each one uses homogenously distributed silica nanoparticles of a particular size. The effect of the nanoparticle size of the first layer on the final roughness of the coating is studied. The first layer enables to adjust the distance between the silica nanoparticles of the upper layer, leading to a tuneable and controlled final roughness. An optimal size nanoparticle has been found for higher water-repellency. Furthermore, the stability of the coating on polymeric surface (Polycarbonate substrate) is ensured by photopolymerization of hybridized silica nanoparticles using Vinyl functional groups.

  6. Directed self-assembly of hybrid oxide/polymer core/shell nanowires with transport optimized morphology for photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shanju; Pelligra, Candice I.; Keskar, Gayatri; Majewski, Pawel W.; Taylor, Andre D.; Pfefferle, Lisa D.; Osuji, Chinedum O. [Department of Chemical and Environmental Engineering, Yale University, New Haven, CT (United States); Jiang, Jie; Ismail-Beigi, Sohrab [Department of Applied Physics, Yale University, New Haven, CT (United States)

    2012-01-03

    An entirely bottom-up approach for the preparation of liquid crystalline suspensions of core-shell nanowires for ordered bulk heterojunction photovoltaics is demonstrated. Side-on attachment of polythiophene derivatives to ZnO nanowires promotes a co-axial polymer backbone-nanowire arrangement which favors high hole mobility. This strategy offers structural control over multiple length scales and a viable means of fabricating ordered films over large areas. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Codelivery of doxorubicin and triptolide with reduction-sensitive lipid–polymer hybrid nanoparticles for in vitro and in vivo synergistic cancer treatment

    Directory of Open Access Journals (Sweden)

    Wu B

    2017-03-01

    Full Text Available Bo Wu,1,2,* Shu-Ting Lu,1,* Liu-Jie Zhang,2 Ren-Xi Zhuo,2 Hai-Bo Xu,1 Shi-Wen Huang2 1Department of Radiology, Zhongnan Hospital of Wuhan University, 2Key Laboratory of Biomedical Polymers of Ministry of Education, Department of Chemistry, Wuhan University, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: Codelivery is a promising strategy to overcome the limitations of single chemotherapeutic agents in cancer treatment. Despite progress, codelivery of two or more different functional drugs to increase anticancer efficiency still remains a challenge. Here, reduction-sensitive lipid–polymer hybrid nanoparticles (LPNPs drug delivery system composed of monomethoxy-poly(ethylene glycol-S-S-hexadecyl (mPEG-S-S-C16, soybean lecithin, and poly(d,l-lactide-co-glycolide (PLGA was used for codelivery of doxorubicin (DOX and a Chinese herb extract triptolide (TPL. Hydrophobic DOX and TPL could be successfully loaded in LPNPs by self-assembly. More importantly, drug release and cellular uptake experiments demonstrated that the two drugs were reduction sensitive, released simultaneously from LPNPs, and taken up effectively by the tumor cells. DOX/TPL-coloaded LPNPs (DOX/TPL-LPNPs exhibited a high level of synergistic activation with low combination index (CI in vitro and in vivo. Moreover, the highest synergistic therapeutic effect was achieved at the ratio of 1:0.2 DOX/TPL. Further experiments showed that TPL enhanced the uptake of DOX by human oral cavity squamous cell carcinoma cells (KB cells. Overall, DOX/TPL-coencapsulated reduction-sensitive nanoparticles will be a promising strategy for cancer treatment. Keywords: triptolide, codelivery, reduction sensitive, synergistic effect

  8. Stealth lipid polymer hybrid nanoparticles loaded with rutin for effective brain delivery - comparative study with the gold standard (Tween 80): optimization, characterization and biodistribution.

    Science.gov (United States)

    Ishak, Rania A H; Mostafa, Nada M; Kamel, Amany O

    2017-11-01

    The blood-brain barrier is considered the leading physiological obstacle hindering the transport of neurotherapeutics to brain cells. The application of nanotechnology coupled with surfactant coating is one of the efficacious tactics overcoming this barrier. The aim of this study was to develop lipid polymer hybrid nanoparticles (LPHNPs), composed of a polymeric core and a phospholipid shell entangled, for the first time, with PEG-based surfactants (SAA) viz. TPGS or Solutol HS 15 in comparison with the gold standard Tween 80, aiming to enhance brain delivery and escape opsonization. LPHNPs were successfully prepared using modified single-step nanoprecipitation technique, loaded with the flavonoid rutin (RU), extracted from the flowers of Calendula officinalis L., and recently proved as a promising anti-Alzheimer. The effect of the critical process parameters (CPP) viz. PLGA amount, W lecithin /W PLGA ratio, and Tween 80 concentration on critical quality attributes (CQA); entrapment, size and size distribution, was statistically analyzed via design of experiments, and optimized using the desirability function. The optimized CPP were maintained while substituting Tween 80 with other PEG-SAA. All hybrid particles exhibited spherical shape with perceptible lipid shells. The biocompatibility of the prepared NPs was confirmed by hemolysis test. The pharmacokinetic assessments, post-intravenous administration to rats, revealed a significant higher RU bioavailability for NPs relative to drug solution. Biodistribution studies proved non-significant differences in RU accumulation within brain, but altered phagocytic uptake among various LPHNPs. The present study endorses the successful development of LPHNPs using PEG-SAA, and confirms the prospective applicability of TPGS and Solutol in enhancing brain delivery.

  9. Relationship between the dielectric and mechanical properties and the ratio of epoxy resin to hardener of the hybrid thermosetting polymers

    International Nuclear Information System (INIS)

    Dias Filho, Newton Luiz; Aquino, Hermes Adolfo de; Pires, Geovanna; Caetano, Laercio

    2006-01-01

    The relationship between the dielectric properties (dielectric constant, ε'', and loss factor, ε''; activation energy, E a ) and the ratio of epoxy resin (OG) to hardener of the epoxy resin thermosetting polymers was investigated. The amplitude of the ε'' peak decreases with increasing OG content until about 73 wt.% and slightly increases at higher OG content. The temperature of the position of the ε'' peak increases with the increasing of OG content, reaching maximum values for compositions in the range of 67 and 73 wt.%, and then it decreases sharply at higher OG content. The activation energy obtained from dielectric relaxation increased with increasing wt.% OG up to around 70 wt.%. Further increase in concentration of OG up to 83 wt.% reduced E a . The curves of tensile modulus and fracture (author)

  10. Relationship between the dielectric and mechanical properties and the ratio of epoxy resin to hardener of the hybrid thermosetting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Dias Filho, Newton Luiz; Aquino, Hermes Adolfo de; Pires, Geovanna; Caetano, Laercio [UNESP, Ilha Solteira, SP (Brazil). Faculdade de Engenharia. Dept. de Fisica e Quimica]. E-mail: nldias@dfq.feis.unesp.br

    2006-05-15

    The relationship between the dielectric properties (dielectric constant, {epsilon}'', and loss factor, {epsilon}''; activation energy, E{sub a}) and the ratio of epoxy resin (OG) to hardener of the epoxy resin thermosetting polymers was investigated. The amplitude of the {epsilon}'' peak decreases with increasing OG content until about 73 wt.% and slightly increases at higher OG content. The temperature of the position of the {epsilon}'' peak increases with the increasing of OG content, reaching maximum values for compositions in the range of 67 and 73 wt.%, and then it decreases sharply at higher OG content. The activation energy obtained from dielectric relaxation increased with increasing wt.% OG up to around 70 wt.%. Further increase in concentration of OG up to 83 wt.% reduced E{sub a}. The curves of tensile modulus and fracture (author)

  11. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes/polymer composite thin film.

    Science.gov (United States)

    Rajanna, Pramod Mulbagal; Gilshteyn, Evgenia; Yagafarov, Timur; Alekseeva, Alena; Anisimov, Anton; Sergeev, Oleg; Neumueller, Alex; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert

    2018-01-09

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and a thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high quality SWCNTs with an enhanced conductivity by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with different SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit Jsc, open-circuit Voc, and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and efficiency of 3.4% under simulated one-sun AM 1.5G direct illumination. © 2018 IOP Publishing Ltd.

  12. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes and polymer composite thin film

    Science.gov (United States)

    Rajanna, Pramod M.; Gilshteyn, Evgenia P.; Yagafarov, Timur; Aleekseeva, Alena K.; Anisimov, Anton S.; Neumüller, Alex; Sergeev, Oleg; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert G.

    2018-03-01

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high-quality SWCNTs with conductivity enhanced by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with varying SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit J sc , open-circuit V oc , and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and an efficiency of 3.4% under simulated one-sun AM 1.5 G direct illumination.

  13. 2.5-Gb/s hybridly-integrated tunable external cavity laser using a superluminescent diode and a polymer Bragg reflector.

    Science.gov (United States)

    Yoon, Ki-Hong; Oh, Su Hwan; Kim, Ki Soo; Kwon, O-Kyun; Oh, Dae Kon; Noh, Young-Ouk; Lee, Hyung-Jong

    2010-03-15

    We presented a hybridly-integrated tunable external cavity laser with 0.8 nm mode spacing 16 channels operating in the direct modulation of 2.5-Gbps for a low-cost source of a WDM-PON system. The tunable laser was fabricated by using a superluminescent diode (SLD) and a polymer Bragg reflector. The maximum output power and the power slope efficiency of the tunable laser were 10.3 mW and 0.132 mW/mA, respectively, at the SLD current of 100 mA and the temperature of 25 degrees C. The directly-modulated tunable laser successfully provided 2.5-Gbps transmissions through 20-km standard single mode fiber. The power penalty of the tunable laser was less than 0.8 dB for 16 channels after a 20-km transmission. The power penalty variation was less than 1.4 dB during the blue-shifted wavelength tuning.

  14. Synthetic surfactant- and cross-linker-free preparation of highly stable lipid-polymer hybrid nanoparticles as potential oral delivery vehicles.

    Science.gov (United States)

    Wang, Taoran; Xue, Jingyi; Hu, Qiaobin; Zhou, Mingyong; Chang, Chao; Luo, Yangchao

    2017-06-05

    The toxicity associated with concentrated synthetic surfactants and the poor stability at gastrointestinal condition are two major constraints for practical applications of solid lipid nanoparticles (SLN) as oral delivery vehicles. In this study, a synthetic surfactant-free and cross-linker-free method was developed to fabricate effective, safe, and ultra-stable lipid-polymer hybrid nanoparticles (LPN). Bovine serum albumin (BSA) and dextran varying in molecular weights were first conjugated through Maillard reaction and the conjugates were exploited to emulsify solid lipid by a solvent diffusion and sonication method. The multilayer structure was formed by self-assembly of BSA-dextran micelles to envelope solid lipid via a pH- and heating-induced facile process with simultaneous surface deposition of pectin. The efficiency of different BSA-dextran conjugates was systematically studied to prepare LPN with the smallest size, the most homogeneous distribution and the greatest stability. The molecular interactions were characterized by Fourier transform infrared and fluorescence spectroscopies. Both nano spray drying and freeze-drying methods were tested to produce spherical and uniform pectin-coated LPN powders that were able to re-assemble nanoscale structure when redispersed in water. The results demonstrated the promise of a synthetic surfactant- and cross-linker-free technique to prepare highly stable pectin-coated LPN from all natural biomaterials as potential oral delivery vehicles.

  15. Chemical sensors of benzene and toluene based on inorganic and hybrid organic-inorganic polymers elaborated by a sol-gel process

    International Nuclear Information System (INIS)

    Calvo Munoz, Maria Luisa

    2000-01-01

    As mono-cyclic aromatic hydrocarbons (MAH) are a matter of concern in terms of pollution, and are to be monitored due to new regulations regarding air quality control, this research thesis first aims at explaining why these compounds are to be monitored, at recalling their sources, at outlining what we know about their negative impact on health and how this impact is determined, which are the means implemented to monitor these compounds and which are their drawbacks, and at recalling which requirements are defined by European directives. The author then reports a literature survey of the current technology regarding chemical sensors, and identifies the required characteristics of an ideal sensor. The author proposes a review of studied performed on sol-gel process and of inorganic polymer synthesis methods based on sol-gel process. He reports the synthesis and characterization of inorganic or hybrid organic-inorganic host matrices, monolithic or in thin layers, used to produce MAH sensors. A matrix pore local polarity study is reported. Benzene and toluene trapping is studied with respect to the polarity and thickness of the host matrix. Pollutant trapping is directly monitored by their absorption in the near-UV and visible range. The author finally reports the study of interactions between fluorescent probe molecules and pollutants, as well as the effect of an interfering gas (oxygen) on the fluorescence of probe molecules [fr

  16. Biomechanical and histologic evaluation of tissue engineered ligaments using chitosan and hyaluronan hybrid polymer fibers: a rabbit medial collateral ligament reconstruction model.

    Science.gov (United States)

    Irie, Toru; Majima, Tokifumi; Sawaguchi, Naohiro; Funakoshi, Tadanao; Nishimura, Shin-Ichiro; Minami, Akio

    2011-05-01

    In this study, we used a rabbit medial collateral ligament reconstruction model to evaluate a novel chitosan-based hyaluronan hybrid polymer fiber scaffold for ligament tissue engineering and to examine whether mechanical forces exerted in an in vivo model increased extracellular matrix production by seeded fibroblasts. Scaffolds were used 2 weeks after incubation with fibroblasts obtained from the same rabbit in a cell-seeded scaffold (CSS) group and without cells in a noncell-seeded scaffold (NCSS) group. At 3, 6, and 12 weeks after surgery, the failure loads of the engineered ligaments in the CSS groups were significantly greater than those in the NCSS groups. At 6 weeks after surgery, the reconstructed tissue of the CSS group was positive for type I collagen, whereas that in the NCSS group was negative for type I collagen. At 12 weeks after surgery, the reconstructed tissue stained positive for type I collagen in the CSS group, but negative in the NCSS group. Our results indicate that the scaffold material enhanced the production of type I collagen and led to improved mechanical strength in the engineered ligament in vivo. Copyright © 2011 Wiley Periodicals, Inc.

  17. Residue-and-polymer-free graphene transfer: DNA-CTMA/graphene/GaN bio-hybrid photodiode for light-sensitive applications

    Science.gov (United States)

    Reddy, M. Siva Pratap; Park, Herie; Lee, Jung-Hee

    2018-02-01

    In this work, we present a residue-and-polymer-free graphene transfer method by using the adhesive force between graphene and a target substrate, the hydrophobic property of graphene, and the surface tension of the solutions. We used an n-type GaN substrate as the target substrate to make a photodiode (PD). Recently, the inclusion of biomolecules in photodetection technology has attracted considerable attention in the electronics and photonics research, particularly due to the rapid evolution of organic-inorganic bio-hybrid PDs (Bio-HPDs). This report presents a significant photoresponse of the bioinspired graphene-based PD fabricated with deoxyribonucleic acid-cetyltrimetylammonium chloride (DNA-CTMA) biomolecules on the n-type GaN substrate. Bio-HPDs respond to the infrared, visible, and ultraviolet wavelengths. Moreover, the Bio-HPDs show photosensitivities (Iphoto/Idark) of 21, 143, and 1194 for infrared, visible, and ultraviolet wavebands, respectively, which can be attributed to the integration of high-mobility graphene and photosensitive DNA-CTMA biomolecules. In addition, the corresponding charge transfer mechanisms in the PDs are explained by energy band diagrams.

  18. Determination of catecholamine in human serum by a fluorescent quenching method based on a water-soluble fluorescent conjugated polymer-enzyme hybrid system.

    Science.gov (United States)

    Huang, Hui; Gao, Yuan; Shi, Fanping; Wang, Guannan; Shah, Syed Mazhar; Su, Xingguang

    2012-03-21

    In this paper, a sensitive water-soluble fluorescent conjugated polymer biosensor for catecholamine (dopamine DA, adrenaline AD and norepinephrine NE) was developed. In the presence of horse radish peroxidase (HRP) and H(2)O(2), catecholamine could be oxidized and the oxidation product of catecholamine could quench the photoluminescence (PL) intensity of poly(2,5-bis(3-sulfonatopropoxy)-1,4-phenylethynylenealt-1,4-poly(phenylene ethynylene)) (PPESO(3)). The quenching PL intensity of PPESO(3) (I(0)/I) was proportional to the concentration of DA, AD and NE in the concentration ranges of 5.0 × 10(-7) to 1.4 × 10(-4), 5.0 × 10(-6) to 5.0 × 10(-4), and 5.0 × 10(-6) to 5.0 × 10(-4) mol L(-1), respectively. The detection limit for DA, AD and NE was 1.4 × 10(-7) mol L(-1), 1.0 × 10(-6) and 1.0 × 10(-6) mol L(-1), respectively. The PPESO(3)-enzyme hybrid system based on the fluorescence quenching method was successfully applied for the determination of catecholamine in human serum samples with good accuracy and satisfactory recovery. The results were in good agreement with those provided by the HPLC-MS method.

  19. Codelivery of doxorubicin and triptolide with reduction-sensitive lipid–polymer hybrid nanoparticles for in vitro and in vivo synergistic cancer treatment

    Science.gov (United States)

    Wu, Bo; Lu, Shu-Ting; Zhang, Liu-Jie; Zhuo, Ren-Xi; Xu, Hai-Bo; Huang, Shi-Wen

    2017-01-01

    Codelivery is a promising strategy to overcome the limitations of single chemotherapeutic agents in cancer treatment. Despite progress, codelivery of two or more different functional drugs to increase anticancer efficiency still remains a challenge. Here, reduction-sensitive lipid–polymer hybrid nanoparticles (LPNPs) drug delivery system composed of monomethoxy-poly(ethylene glycol)-S-S-hexadecyl (mPEG-S-S-C16), soybean lecithin, and poly(D,L-lactide-co-glycolide) (PLGA) was used for codelivery of doxorubicin (DOX) and a Chinese herb extract triptolide (TPL). Hydrophobic DOX and TPL could be successfully loaded in LPNPs by self-assembly. More importantly, drug release and cellular uptake experiments demonstrated that the two drugs were reduction sensitive, released simultaneously from LPNPs, and taken up effectively by the tumor cells. DOX/TPL-coloaded LPNPs (DOX/TPL-LPNPs) exhibited a high level of synergistic activation with low combination index (CI) in vitro and in vivo. Moreover, the highest synergistic therapeutic effect was achieved at the ratio of 1:0.2 DOX/TPL. Further experiments showed that TPL enhanced the uptake of DOX by human oral cavity squamous cell carcinoma cells (KB cells). Overall, DOX/TPL-coencapsulated reduction-sensitive nanoparticles will be a promising strategy for cancer treatment. PMID:28331310

  20. Codelivery of doxorubicin and triptolide with reduction-sensitive lipid-polymer hybrid nanoparticles for in vitro and in vivo synergistic cancer treatment.

    Science.gov (United States)

    Wu, Bo; Lu, Shu-Ting; Zhang, Liu-Jie; Zhuo, Ren-Xi; Xu, Hai-Bo; Huang, Shi-Wen

    2017-01-01

    Codelivery is a promising strategy to overcome the limitations of single chemotherapeutic agents in cancer treatment. Despite progress, codelivery of two or more different functional drugs to increase anticancer efficiency still remains a challenge. Here, reduction-sensitive lipid-polymer hybrid nanoparticles (LPNPs) drug delivery system composed of monomethoxy-poly(ethylene glycol)- S - S -hexadecyl (mPEG- S - S -C 16 ), soybean lecithin, and poly(D,L-lactide-co-glycolide) (PLGA) was used for codelivery of doxorubicin (DOX) and a Chinese herb extract triptolide (TPL). Hydrophobic DOX and TPL could be successfully loaded in LPNPs by self-assembly. More importantly, drug release and cellular uptake experiments demonstrated that the two drugs were reduction sensitive, released simultaneously from LPNPs, and taken up effectively by the tumor cells. DOX/TPL-coloaded LPNPs (DOX/TPL-LPNPs) exhibited a high level of synergistic activation with low combination index (CI) in vitro and in vivo. Moreover, the highest synergistic therapeutic effect was achieved at the ratio of 1:0.2 DOX/TPL. Further experiments showed that TPL enhanced the uptake of DOX by human oral cavity squamous cell carcinoma cells (KB cells). Overall, DOX/TPL-coencapsulated reduction-sensitive nanoparticles will be a promising strategy for cancer treatment.

  1. Co-delivery of pemetrexed and miR-21 antisense oligonucleotide by lipid-polymer hybrid nanoparticles and effects on glioblastoma cells.

    Science.gov (United States)

    Küçüktürkmen, Berrin; Devrim, Burcu; Saka, Ongun M; Yilmaz, Şükran; Arsoy, Taibe; Bozkir, Asuman

    2017-01-01

    Combination therapy using anticancer drugs and nucleic acid is a more promising strategy to overcome multidrug resistance in cancer and to enhance apoptosis. In this study, lipid-polymer hybrid nanoparticles (LPNs), which contain both pemetrexed and miR-21 antisense oligonucleotide (anti-miR-21), have been developed for treatment of glioblastoma, the most aggressive type of brain tumor. Prepared LPNs have been well characterized by particle size distribution and zeta potential measurements, determination of encapsulation efficiency, and in vitro release experiments. Morphology of LPNs was determined by transmission electron microscopy. LPNs had a hydrodynamic size below 100 nm and exhibited sustained release of pemetrexed up to 10 h. Encapsulation of pemetrexed in LPNs increased cellular uptake from 6% to 78%. Results of confocal microscopy analysis have shown that co-delivery of anti-miR-21 significantly improved accumulation of LPNs in the nucleus of U87MG cells. Nevertheless, more effective cytotoxicity results could not be obtained due to low concentration of anti-miR-21, loaded in LPNs. We expect that the effective drug delivery systems can be obtained with higher concentration of anti-miR-21 for the treatment of glioblastoma.

  2. Nanosized TiN-SBR hybrid coating of stainless steel as bipolar plates for polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Kumagai, Masanobu; Myung, Seung-Taek; Asaishi, Ryo; Sun, Yang-Kook; Yashiro, Hitoshi

    2008-01-01

    In attempt to improve interfacial electrical conductivity of stainless steel for bipolar plates of polymer electrolyte membrane fuel cells, TiN nanoparticles were electrophoretically deposited on the surface of stainless steel with elastic styrene butadiene rubber (SBR) particles. From transmission electron microscopic observation, it was found that the TiN nanoparticles (ca. 50 nm) surrounded the spherical SBR particles (ca. 300-600 nm), forming agglomerates. They were well adhered on the surface of the type 310S stainless steel. With help of elasticity of SBR, the agglomerates were well fitted into the interfacial gap between gas diffusion layer (GDL) and stainless steel bipolar plate, and the interfacial contact resistance (ICR), simultaneously, was successfully reduced. A single cell using the TiN nanoparticles-coated bipolar plates, consequently, showed comparable cell performance with the graphite employing cell at a current density of 0.5 A cm -2 (12.5 A). Inexpensive TiN nanoparticle-coated type 310S stainless steel bipolar plates would become a possible alternate for the expensive graphite bipolar plates as use in fuel cell applications

  3. Bio-inspired Construction of Advanced Fuel Cell Cathode with Pt Anchored in Ordered Hybrid Polymer Matrix.

    Science.gov (United States)

    Xia, Zhangxun; Wang, Suli; Jiang, Luhua; Sun, Hai; Liu, Shuang; Fu, Xudong; Zhang, Bingsen; Sheng Su, Dang; Wang, Jianqiang; Sun, Gongquan

    2015-11-05

    The significant use of platinum for catalyzing the cathodic oxygen reduction reactions (ORRs) has hampered the widespread use of polymer electrolyte membrane fuel cells (PEMFCs). The construction of well-defined electrode architecture in nanoscale with enhanced utilization and catalytic performance of Pt might be a promising approach to address such barrier. Inspired by the highly efficient catalytic processes in enzymes with active centers embedded in charge transport pathways, here we demonstrate for the first time a design that allocates platinum nanoparticles (Pt NPs) at the boundaries with dual-functions of conducting both electrons by aid of polypyrrole and protons via Nafion(®) ionomer within hierarchical nanoarrays. By mimicking enzymes functionally, an impressive ORR activity and stability is achieved. Using this brand new electrode architecture as the cathode and the anode of a PEMFC, a high mass specific power density of 5.23 W mg(-1)Pt is achieved, with remarkable durability. These improvements are ascribed to not only the electron decoration and the anchoring effects from the Nafion(®) ionomer decorated PPy substrate to the supported Pt NPs, but also the fast charge and mass transport facilitated by the electron and proton pathways within the electrode architecture.

  4. Synthesis, Morphology, and Optical Properties of Au/CdS Hybrid Nanocomposites Stabilized by Branched Polymer Matrices

    Directory of Open Access Journals (Sweden)

    V. A. Chumachenko

    2016-01-01

    Full Text Available Metal/semiconductor (Au/CdS nanocomposites were synthesized in the solution of branched D-g-PAA polymer. TEM and DLS of Au/CdS/D-g-PAA nanocomposites revealed complicated nanocomposite structure consisting of the Au nanoparticles (NPs of 6 nm in size surrounded by small CdS NPs with size of 3 nm. These nanocomposites formed the aggregates-clusters with average size of 50–800 nm. Absorption spectra of Au/CdS nanocomposites consist of the bands of excitons in CdS NPs and surface plasmons in Au ones. The surface plasmon band of gold NPs is red shifted and broadened in Au/CdS/D-g-PAA nanocomposites comparing to the one of Au NPs in Au/D-g-PAA proving the fact of close location of CdS and Au NPs in the synthesized Au/CdS/D-g-PAA nanocomposites. The PL spectra of Au/CdS nanocomposites originate from the radiative transitions in excitons in CdS NPs. The 4-fold increase of intensity of free exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA that is due to PL enhancement by local field of surface plasmons of Au NPs. Also, the 12-fold decrease of intensity of localized exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA. Most probably, it is due to passivation of the surface of CdS NPs carried out by the Au ones.

  5. Polymer-Based Black Phosphorus (bP) Hybrid Materials by in Situ Radical Polymerization: An Effective Tool To Exfoliate bP and Stabilize bP Nanoflakes

    Science.gov (United States)

    2018-01-01

    Black phosphorus (bP) has been recently investigated for next generation nanoelectronic multifunctional devices. However, the intrinsic instability of exfoliated bP (the bP nanoflakes) toward both moisture and air has so far overshadowed its practical implementation. In order to contribute to fill this gap, we report here the preparation of new hybrid polymer-based materials where bP nanoflakes (bPn) exhibit a significantly improved stability. The new materials have been prepared by different synthetic paths including: (i) the mixing of conventionally liquid-phase exfoliated bP (in dimethyl sulfoxide, DMSO) with poly(methyl methacrylate) (PMMA) solution; (ii) the direct exfoliation of bP in a polymeric solution; (iii) the in situ radical polymerization after exfoliating bP in the liquid monomer (methyl methacrylate, MMA). This last methodology concerns the preparation of stable suspensions of bPn–MMA by sonication-assisted liquid-phase exfoliation (LPE) of bP in the presence of MMA followed by radical polymerization. The hybrids characteristics have been compared in order to evaluate the bP dispersion and the effectiveness of the bPn interfacial interactions with polymer chains aimed at their long-term environmental stabilization. The passivation of the bPn is particularly effective when the hybrid material is prepared by in situ polymerization. By using this synthetic methodology, the nanoflakes, even if with a gradient of dispersion (size of aggregates), preserve their chemical structure from oxidation (as proved by both Raman and 31P-solid state NMR studies) and are particularly stable to air and UV light exposure. The feasibility of this approach, capable of efficiently exfoliating bP while protecting the bPn, has been then verified by using different vinyl monomers (styrene and N-vinylpyrrolidone), thus obtaining hybrids where the nanoflakes are embedded in polymer matrices with a variety of intriguing thermal, mechanical, and solubility characteristics.

  6. Synthesis of hydrazide-functionalized hydrophilic polymer hybrid graphene oxide for highly efficient N-glycopeptide enrichment and identification by mass spectrometry.

    Science.gov (United States)

    Bai, Haihong; Pan, Yiting; Guo, Cong; Zhao, Xinyuan; Shen, Bingquan; Wang, Xinghe; Liu, Zeyuan; Cheng, Yuanguo; Qin, Weijie; Qian, Xiaohong

    2017-08-15

    Protein N-glycosylation is one of the most important post-translational modifications, participating in many key biological and pathological processes. Large-scale and precise identification of N-glycosylated proteins and peptides is especially beneficial for understanding their biological functions and for discovery of new clinical biomarkers and therapeutic drug targets. However, protein N-glycosylation is microheterogeneous and low abundant in living organisms, therefore specific enrichment of N-glycosylated proteins/peptides before mass spectrometry analysis is a prerequisite. In this work, we developed a new type of polymer hybrid graphene oxide (GO) by in situ growth of hydrazide-functionalized hydrophilic polymer chains on the GO surface (GO-PAAH) for selective N-glycopeptide enrichment and identification by mass spectrometry. The densely attached and low steric hindrance hydrazide groups as well as the highly hydrophilic nature of GO-PAAH facilitate N-glycopeptide enrichment by the combination of hydrazide capturing and HILIC interaction. Taking advantage of the unique features of GO-PAAH, all of the three N-glycopeptides of bovine fetuin were successfully enriched and identified with significantly enhanced signal intensities from a digest mixture of bovine fetuin and bovine serum albumin at a mass ratio of 1:100, demonstrating the excellent enrichment selectivity of GO-PAAH. Furthermore, a total of 507 N-glycosylation sites and 480 N-glycopeptides in 232 N-glycoproteins were enriched and identified from 10μL of human serum by three replicates using this novel enrichment material, which is nearly two times higher than the commercial hydrazide resin based method (280 N-glycosylation sites, 261 N-glycopeptides and 144 N-glycoproteins in three experiments). Among the identified, 95 N-glycosylation sites were not reported in the Uniprot database, and 106 N-glycoproteins were disease related in the Nextprot database, indicating the potential of this new

  7. A strong adjuvant based on glycol-chitosan-coated lipid-polymer hybrid nanoparticles potentiates mucosal immune responses against the recombinant Chlamydia trachomatis fusion antigen CTH522.

    Science.gov (United States)

    Rose, Fabrice; Wern, Jeanette Erbo; Gavins, Francesca; Andersen, Peter; Follmann, Frank; Foged, Camilla

    2018-02-10

    Induction of mucosal immunity with vaccines is attractive for the immunological protection against pathogen entry directly at the site of infection. An example is infection with Chlamydia trachomatis (Ct), which is the most common sexually transmitted infection in the world, and there is an unmet medical need for an effective vaccine. A vaccine against Ct should elicit protective humoral and cell-mediated immune (CMI) responses in the genital tract mucosa. We previously designed an antibody- and CMI-inducing adjuvant based on poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles modified with the cationic surfactant dimethyldioctadecylammonium bromide and the immunopotentiator trehalose-6,6'-dibehenate. Here we show that immunization with these lipid-polymer hybrid nanoparticles (LPNs) coated with the mucoadhesive polymer chitosan enhances mucosal immune responses. Glycol chitosan (GC)-modified LPNs were engineered using an oil-in-water single emulsion solvent evaporation method. The nanoparticle design was optimized in a highly systematic way by using a quality-by-design approach to define the optimal operating space and to gain maximal mechanistic information about the GC coating of the LPNs. Cryo-transmission electron microscopy revealed a PLGA core coated with one or several concentric lipid bilayers. The GC coating of the surface was identified as a saturable, GC concentration-dependent increase in particle size and a reduction of the zeta-potential, and the coating layer could be compressed upon addition of salt. Increased antigen-specific mucosal immune responses were induced in the lungs and the genital tract with the optimized GC-coated LPN adjuvant upon nasal immunization of mice with the recombinant Ct fusion antigen CTH522. The mucosal responses were characterized by CTH522-specific IgG/IgA antibodies, together with CTH522-specific interferon γ-producing Th1 cells. This study demonstrates that mucosal administration of CTH522 adjuvanted with chitosan

  8. Cyclic behavior, development, and characteristics of a ductile hybrid fiber-reinforced polymer (DHFRP) for reinforced concrete members

    Science.gov (United States)

    Hampton, Francis Patrick

    Reinforced concrete (R/C) structures especially pavements and bridge decks that constitute vital elements of the infrastructure of all industrialized societies are deteriorating prematurely. Structural repair and upgrading of these structural elements have become a more economical option for constructed facilities especially in the United States and Canada. One method of retrofitting concrete structures is the use of advanced materials. Fiber reinforced polymer (FRP) composite materials typically are in the form of fabric sheets or reinforcing bars. While the strength and stiffness of the FRP is high, composites are inherently brittle, with limited or no ductility. Conventional FRP systems cannot currently meet ductility demand, and therefore, may fail in a catastrophic failure mode. The primary goal of this research was to develop an optimized prototype 10-mm diameter DHFRP bar. The behavior of the bar under full load reversals to failure was investigated. However, this bar first needed to be designed and manufactured in the Fibrous Materials Research at Drexel University. Material properties were determined through testing to categorize the strength properties of the DHFRP. Similitude was used to demonstrate the scaling of properties from the original model bars. The four most important properties of the DHFRP bars are sufficient strength and stiffness, significant ductility for plasticity to develop in the R/C section, and sufficient bond strength for the R/C section to develop its full strength. Once these properties were determined the behavior of reinforced concrete members was investigated. This included the testing of prototype-size beams under monotonic loading and model and prototype beam-columns under reverse cyclic loading. These tests confirmed the large ductility exhibited by the DHFRP. Also the energy absorption capacity of the bar was demonstrated by the hysteretic behavior of the beam-columns. Displacement ductility factors in the range of 3

  9. Panchromatic response composed of hybrid visible-light absorbing polymers and near-IR absorbing dyes for nanocrystalline TiO{sub 2}-based solid-state solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyo Joong; Graetzel, Michael; Nazeeruddin, Md. Khaja [Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland); Leventis, Henry C.; Haque, Saif A. [Department of Chemistry, Imperial College of Science Technology and Medicine, London SW72AZ (United Kingdom); Torres, Tomas [Departamento de Quimica Organica, Universidad Autonoma de Madrid (UAM), 28049 Madrid (Spain)

    2011-01-01

    In pursuit of panchromatic sensitizers for mesoporous TiO{sub 2}-based solid-state solar cells, a near-IR absorbing zinc phthalocyanine dye (coded TT1) was firstly adsorbed over relatively thin ({proportional_to}1 {mu}m) TiO{sub 2} mesoporous films and then a visible-light absorbing polymer [regioregular poly(3-hexylthiophene), P3HT] was incorporated into the mesopores as both a second sensitizer and a solid hole conductor. After optimizing some experimental parameters, these hybrid solid-state cells exhibited a clear panchromatic response, and an overall conversion efficiency of around 1% at full sun intensity. (author)

  10. Hybrid Lipid/Polymer Nanoparticles for Pulmonary Delivery of siRNA: Development and Fate Upon In Vitro Deposition on the Human Epithelial Airway Barrier.

    Science.gov (United States)

    d'Angelo, Ivana; Costabile, Gabriella; Durantie, Estelle; Brocca, Paola; Rondelli, Valeria; Russo, Annapina; Russo, Giulia; Miro, Agnese; Quaglia, Fabiana; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Ungaro, Francesca

    2017-10-16

    Nowadays, the downregulation of genes involved in the pathogenesis of severe lung diseases through local siRNA delivery appears an interesting therapeutic approach. In this study, we propose novel hybrid lipid-polymer nanoparticles (hNPs) consisting of poly(lactic-co-glycolic) acid (PLGA) and dipalmitoyl phosphatidylcholine (DPPC) as siRNA inhalation system. A panel of DPPC/PLGA hNPs was prepared by emulsion/solvent diffusion and fully characterized. A combination of model siRNAs against the sodium transepithelial channel (ENaC) was entrapped in optimized hNPs comprising or not poly(ethylenimine) (PEI) as third component. siRNA-loaded hNPs were characterized for encapsulation efficiency, release kinetics, aerodynamic properties, and stability in artificial mucus (AM). The fate and cytotoxicity of hNPs upon aerosolization on a triple cell co-culture model (TCCC) mimicking human epithelial airway barrier were assessed. Finally, the effect of siRNA-loaded hNPs on ENaC protein expression at 72 hours was evaluated in A549 cells. Optimized muco-inert hNPs encapsulating model siRNA with high efficiency were produced. The developed hNPs displayed a hydrodynamic diameter of ∼150 nm, a low polydispersity index, a negative ζ potential close to -25 mV, and a peculiar triphasic siRNA release lasting for 5 days, which slowed down in the presence of PEI. siRNA formulations showed optimal in vitro aerosol performance after delivery with a vibrating mesh nebulizer. Furthermore, small-angle X-ray scattering analyses highlighted an excellent stability upon incubation with AM, confirming the potential of hNPs for direct aerosolization on mucus-lined airways. Studies in TCCC confirmed that fluorescent hNPs are internalized inside airway epithelial cells and do not exert any cytotoxic or acute proinflammatory effect. Finally, a prolonged inhibition of ENaC protein expression was observed in A549 cells upon treatment with siRNA-loaded hNPs. Results demonstrate the great potential

  11. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin-Kyu; Dung, Mai Xuan; Jeong, Hyun-Dam, E-mail: hdjeong@chonnam.ac.kr

    2014-11-14

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD.

  12. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    International Nuclear Information System (INIS)

    Choi, Jin-Kyu; Dung, Mai Xuan; Jeong, Hyun-Dam

    2014-01-01

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD

  13. Polymer films

    Science.gov (United States)

    Granick, Steve; Sukhishvili, Svetlana A.

    2004-05-25

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  14. The Influence of the Polymer Amount on the Biological Properties of PCL/ZrO2 Hybrid Materials Synthesized via Sol-Gel Technique

    Directory of Open Access Journals (Sweden)

    Michelina Catauro

    2017-10-01

    Full Text Available Organic/inorganic hybrid materials are attracting considerable attention in the biomedical area. The sol-gel process provides a convenient way to produce many bioactive organic–inorganic hybrids. Among those, poly(e-caprolactone/zirconia (PCL/ZrO2 hybrids have proved to be bioactive with no toxic materials. The aim of this study was to investigate the effects of these materials on the cellular response as a function of the PCL content, in order to evaluate their potential use in the biomedical field. For this purpose, PCL/ZrO2 hybrids containing 6, 12, 24, and 50 wt % of PCL were synthesized by the sol-gel method. The effects of their presence on the NIH-3T3 fibroblast cell line carrying out direct cell number counting, MTT, cell damage assays, flow cytometry-based analysis of cell-cycle progression, and immunoblotting experiments. The results confirm and extend the findings that PCL/ZrO2 hybrids are free from toxicity. The hybrids containing 12 and 24 wt % PCL, (more than 6 and 50 wt % ones enhance cell proliferation when compared to pure ZrO2 by affecting cell cycle progression. The finding that the content of PCL in PCL/ZrO2 hybrids differently supports cell proliferation suggests that PCL/ZrO2 hybrids could be useful tools with different potential clinical applications.

  15. The Influence of the Polymer Amount on the Biological Properties of PCL/ZrO2 Hybrid Materials Synthesized via Sol-Gel Technique

    Science.gov (United States)

    Tranquillo, Elisabetta; Illiano, Michela; Sapio, Luigi; Spina, Annamaria; Naviglio, Silvio

    2017-01-01

    Organic/inorganic hybrid materials are attracting considerable attention in the biomedical area. The sol-gel process provides a convenient way to produce many bioactive organic–inorganic hybrids. Among those, poly(e-caprolactone)/zirconia (PCL/ZrO2) hybrids have proved to be bioactive with no toxic materials. The aim of this study was to investigate the effects of these materials on the cellular response as a function of the PCL content, in order to evaluate their potential use in the biomedical field. For this purpose, PCL/ZrO2 hybrids containing 6, 12, 24, and 50 wt % of PCL were synthesized by the sol-gel method. The effects of their presence on the NIH-3T3 fibroblast cell line carrying out direct cell number counting, MTT, cell damage assays, flow cytometry-based analysis of cell-cycle progression, and immunoblotting experiments. The results confirm and extend the findings that PCL/ZrO2 hybrids are free from toxicity. The hybrids containing 12 and 24 wt % PCL, (more than 6 and 50 wt % ones) enhance cell proliferation when compared to pure ZrO2 by affecting cell cycle progression. The finding that the content of PCL in PCL/ZrO2 hybrids differently supports cell proliferation suggests that PCL/ZrO2 hybrids could be useful tools with different potential clinical applications. PMID:29039803

  16. Clay-containing polymer nanocomposites: from fundamentals to real applications

    CSIR Research Space (South Africa)

    Sinha Ray, S

    2013-01-01

    Full Text Available Much research and development effort has emerged in addressing hybrid organic-inorganic systems; particular attention has been given to those systems in which nanofillers are dispersed in polymer matrices. This class of materials called polymer...

  17. A novel polymer of Al2(SO43-poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonate ionic hybrid prepared by dispersion polymerization

    Directory of Open Access Journals (Sweden)

    2010-03-01

    Full Text Available A novel polymer Al2(SO43-poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonate (Al2(SO43-P(AM/AMPS had been synthesized by dispersion polymerization in an aqueous solution of ammonium sulfate and aluminum sulfate, using poly(2-acrylamido-2-methyl-1-propanesulfonate P(AMPS as stabilizer, acrylamide (AM and 2-acrylamido-2-methyl-1-propanesulfonate (AMPS as monomers, poly(2-acrylamido-2-methyl-1-propanesulfonate (PAMPS as stabilizer and [2-(2-imidazdino-2-ylpropane]dihydrochloride (VA-044 as initiator. The average particle size of polymer dispersion ranged from 0.2 to 0.3 µm, the molecular weight was from 4.3•106 to 5.7•106 g•mol-1. The polymer was characterized by infrared (IR spectroscopy, thermogravimetry (TGA and transmission electron microscopy (TEM. The swelling property of the dispersion polymer was studied by particle size distribution. When the polymer dispersion was diluted with deionized water, particle sizes decreased several times. When the polymer dispersion was diluted with salt water, the particle size increased with increasing concentration of salt. The effects of Al2(SO43 and stabilizer on the particle size and the relative molecular weight of the polymer were investigated, respectively. The optimum conditions for the stable Al2(SO43-P(AM/AMPS dispersion were that the concentration of Al2(SO43 was 1.12 wt%, the concentration of PAMPS stabilizer was 3 wt% and the concentration of initiator was 0.2 mol•l-1 and the monomers concentration was 14 wt%.

  18. Synthesis and electrochemical characterization of hybrid membrane Nafion-SiO2 for application as polymer electrolyte in PEM fuel cell

    International Nuclear Information System (INIS)

    Dresch, Mauro Andre

    2009-01-01

    In this work, the effect of sol-gel synthesis parameters on the preparation and polarization response of Nafion-SiO 2 hybrids as electrolytes for proton exchange membrane fuel cells (PEMFC) operating at high temperatures (130 degree C) was evaluated. The inorganic phase was incorporated in a Nafion matrix with the following purposes: to improve the Nafion water uptake at high temperatures (> 100 degree C); to increase the mechanical strength of Nafion and; to accelerate the electrode reactions. The hybrids were prepared by an in-situ incorporation of silica into commercial Nafion membranes using an acid-catalyzed sol-gel route. The effects of synthesis parameters, such as catalyst concentration, sol-gel solvent, temperature and time of both hydrolysis and condensation reactions, and silicon precursor concentration (Tetraethyl orthosilicate - TEOS), were evaluated as a function on the incorporation degree and polarization response. Nafion-SiO 2 hybrids were characterized by gravimetry, thermogravimetric analysis (TGA), scanning electron microscopy and X-ray dispersive energy (SEM-EDS), electrochemical impedance spectroscopy (EIS), and X-ray small angle scattering (SAXS). The hybrids were tested as electrolyte in single H 2 /O 2 fuel cells in the temperature range of 80 - 130 degree C and at 130 degree C and reduced relative humidity (75% and 50%). Summarily, the hybrid performance showed to be strongly dependent on the synthesis parameters, mainly, the type of alcohol and the TEOS concentration. (author)

  19. Fabrication of polymer/cadmium sulfide hybrid solar cells [P3HT:CdS and PCPDTBT:CdS] by spray deposition.

    Science.gov (United States)

    Kumar, Neetesh; Dutta, Viresh

    2014-11-15

    This paper investigates fabrication of surfactant free CdS nanoparticles (NPs) and application in the fabrication of P3HT:CdS and PCPDTBT:CdS bulk-heterojunction hybrid solar cells using high-throughput, large-area, low cost spray deposition technique. Both the hybrid active layers and hole transport layers are deposited by spray technique. The CdS/Poly(3-hexylthiophene-2,5-diyl) (P3HT) and CdS/Poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) hybrid devices are fabricated by spray deposition process at optimized conditions (i.e. film thickness, spray solution volume, distance between sample and spray nozzle, substrate temperature, etc.). The power conversion efficiency of η=0.6% and 1.02% is obtained for P3HT:CdS and PCPDTBT:CdS hybrid devices, respectively. Spray coating holds significant promise as a technique capable of fabricating large-area, high performance hybrid solar cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Biodegradable Polymers

    OpenAIRE

    Vroman, Isabelle; Tighzert, Lan

    2009-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. ...

  1. High-efficiency and conveniently recyclable photo-catalysts for dye degradation based on urchin-like CuO microparticle/polymer hybrid composites

    Science.gov (United States)

    Liu, Xiong; Cheng, Yuming; Li, Xuefeng; Dong, Jinfeng

    2018-05-01

    In this work, we developed a new type of photo-catalysts composed of the urchin-like cupric oxide (CuO) microparticle and polyvinylidene fluoride (PVDF) hybrid composites by the convenient organic-inorganic hybrid strategy, which show high-efficiency and conveniently recyclable for dye degradation including methylene blue (MB), Congo red (CR), and malachite green (MG) by visible light irradiation. The micro-structural characteristics of urchin-like CuO microparticles are crucial and dominant over the photo-degrading efficiency of hybrid catalyst because of their highly exposed {0 0 2} facet and larger specific surface area. Simultaneously, the intrinsic porous framework of PVDF membrane not only remains the excellent photo-catalytic activity of urchin-like CuO microparticles but also facilitates the enrichment of dyes on the membrane, and thereby synergistically contributing to the photo-catalytic efficiency. The microstructures of both urchin-like CuO microparticles and hybrid catalysts are systematically characterized by various techniques including scanning electron microscopy (SEM), transmission electron microscope (TEM), high-resolution transmission electron microscope (HRTEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption/desorption isotherms, which evidently support the mentioned mechanism.

  2. A hybrid, massively parallel implementation of a genetic algorithm for optimization of the impact performance of a metal/polymer composite plate

    KAUST Repository

    Narayanan, Kiran; Mora Cordova, Angel; Allsopp, Nicholas; El Sayed, Tamer S.

    2012-01-01

    A hybrid parallelization method composed of a coarse-grained genetic algorithm (GA) and fine-grained objective function evaluations is implemented on a heterogeneous computational resource consisting of 16 IBM Blue Gene/P racks, a single x86 cluster

  3. Resistive switching of organic–inorganic hybrid devices of conductive polymer and permeable ultra-thin SiO2 films

    Science.gov (United States)

    Yamamoto, Shunsuke; Kitanaka, Takahisa; Miyashita, Tokuji; Mitsuishi, Masaya

    2018-06-01

    We propose a resistive switching device composed of conductive polymer (PEDOT:PSS) and SiO2 ultra-thin films. The SiO2 film was fabricated from silsesquioxane polymer nanosheets as a resistive switching layer. Devices with metal (Ag or Au)∣SiO2∣PEDOT:PSS architecture show good resistive switching performance with set–reset voltages as low as several hundred millivolts. The device properties and the working mechanism were investigated by varying the electrode material, surrounding atmosphere, and SiO2 film thickness. Results show that resistive switching is based on water and ion migration at the PEDOT:PSS∣SiO2 interface.

  4. Synthesis, structure and optical limiting effect of a novel inorganic-organic hybrid polymer containing mixed chains of copper(I)/iodine

    International Nuclear Information System (INIS)

    Li Haohong; Chen Zhirong; Li Junqian; Zhan Hongbing; Zhang Wenxuan; Huang Changcang; Ma Cheng; Zhao Bin

    2006-01-01

    In this paper, treatment of N-ethyl-benzo[f]quinolium (ebq) iodide and CuI with excess KI afforded an unusual coordination polymer [(ebq) 2 (Cu 3 I 4 )(CuI 2 )] n (1). 1 crystallizes in tetragonal system, space group P4(2)bc with cell parameters of a=23.2040(6)A, c=6.7393(3)A, V=3628.6(2)A 3 , Z=8, D c =2.622g/c 3 , R 1 =0.0447 and wR 2 =0.0974. A highly interesting feature of 1 is its presence of mixed types of chains [(Cu 3 I 4 ) n - and (CuI 2 ) n - chain] in one crystal lattice based on supramolecular self-assembly directed by cations. The infinite chains (Cu 3 I 4 ) n - and (CuI 2 ) n - in 1 could be described as the edge-sharing arrangement of CuI 4 tetrahedron. Furthermore, IR, EA, UV-Vis, thermal analysis and optical limiting measurements were adopted to characterize polymer 1. The optical limiting experiment shows that the present polymer exhibits a large optical limiting capacity

  5. Stable and Efficient Organo-Metal Halide Hybrid Perovskite Solar Cells via π-Conjugated Lewis Base Polymer Induced Trap Passivation and Charge Extraction.

    Science.gov (United States)

    Qin, Ping-Li; Yang, Guang; Ren, Zhi-Wei; Cheung, Sin Hang; So, Shu Kong; Chen, Li; Hao, Jianhua; Hou, Jianhui; Li, Gang

    2018-03-01

    High-quality pinhole-free perovskite film with optimal crystalline morphology is critical for achieving high-efficiency and high-stability perovskite solar cells (PSCs). In this study, a p-type π-conjugated polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl) thiophen-2-yl)-benzo[1,2-b:4,5-b'] dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl) benzo[1',2'-c:4',5'-c'] dithiophene-4,8-dione))] (PBDB-T) is introduced into chlorobenzene to form a facile and effective template-agent during the anti-solvent process of perovskite film formation. The π-conjugated polymer PBDB-T is found to trigger a heterogeneous nucleation over the perovskite precursor film and passivate the trap states of the mixed perovskite film through the formation of Lewis adducts between lead and oxygen atom in PBDB-T. The p-type semiconducting and hydrophobic PBDB-T polymer fills in the perovskite grain boundaries to improve charge transfer for better conductivity and prevent moisture invasion into the perovskite active layers. Consequently, the PSCs with PBDB-T modified anti-solvent processing leads to a high-efficiency close to 20%, and the devices show excellent stability, retaining about 90% of the initial power conversion efficiency after 150 d storage in dry air. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Polymer compound

    NARCIS (Netherlands)

    1995-01-01

    A Polymer compound comprising a polymer (a) that contains cyclic imidesgroups and a polymer (b) that contains monomer groups with a 2,4-diamino-1,3,5-triazine side group. According to the formula (see formula) whereby themole percentage ratio of the cyclic imides groups in the polymer compoundwith

  7. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  8. Hybrid Energy Cell with Hierarchical Nano/Micro-Architectured Polymer Film to Harvest Mechanical, Solar, and Wind Energies Individually/Simultaneously.

    Science.gov (United States)

    Dudem, Bhaskar; Ko, Yeong Hwan; Leem, Jung Woo; Lim, Joo Ho; Yu, Jae Su

    2016-11-09

    We report the creation of hybrid energy cells based on hierarchical nano/micro-architectured polydimethylsiloxane (HNMA-PDMS) films with multifunctionality to simultaneously harvest mechanical, solar, and wind energies. These films consist of nano/micro dual-scale architectures (i.e., nanonipples on inverted micropyramidal arrays) on the PDMS surface. The HNMA-PDMS is replicable by facile and cost-effective soft imprint lithography using a nanoporous anodic alumina oxide film formed on the micropyramidal-structured silicon substrate. The HNMA-PDMS film plays multifunctional roles as a triboelectric layer in nanogenerators and an antireflection layer for dye-sensitized solar cells (DSSCs), as well as a self-cleaning surface. This film is employed in triboelectric nanogenerator (TENG) devices, fabricated by laminating it on indium-tin oxide-coated polyethylene terephthalate (ITO/PET) as a bottom electrode. The large effective contact area that emerged from the densely packed hierarchical nano/micro-architectures of the PDMS film leads to the enhancement of TENG device performance. Moreover, the HNMA-PDMS/ITO/PET, with a high transmittance of >90%, also results in highly transparent TENG devices. By placing the HNMA-PDMS/ITO/PET, where the ITO/PET is coated with zinc oxide nanowires, as the top glass substrate of DSSCs, the device is able to add the functionality of TENG devices, thus creating a hybrid energy cell. The hybrid energy cell can successfully convert mechanical, solar, and wind energies into electricity, simultaneously or independently. To specify the device performance, the effects of external pushing frequency and load resistance on the output of TENG devices are also analyzed, including the photovoltaic performance of the hybrid energy cells.

  9. Nanoimprinted polymer photonic crystal dye lasers

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Smith, Cameron; Buss, Thomas

    2010-01-01

    Optically pumped polymer photonic crystal band-edge dye lasers are presented. The photonic crystal is a rectangular lattice providing laser feedback as well as an optical resonance for the pump light. The lasers are defined in a thin film of photodefinable Ormocore hybrid polymer, doped...

  10. Investigation of Coating Performance of UV-Curable Hybrid Polymers Containing 1H,1H,2H,2H-Perfluorooctyltriethoxysilane Coated on Aluminum Substrates

    Directory of Open Access Journals (Sweden)

    Mustafa Çakır

    2017-03-01

    Full Text Available This study describes preparation and characterization of fluorine-containing organic-inorganic hybrid coatings. The organic part consists of bisphenol-A glycerolate (1 glycerol/phenol diacrylate resin and 1,6-hexanediol diacrylate reactive diluent. The inorganically rich part comprises trimethoxysilane-terminated urethane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 3-(trimethoxysilyl propyl methacrylate and sol–gel precursors that are products of hydrolysis and condensation reactions. Bisphenol-A glycerolate (1 glycerol/phenol diacrylate resin was added to the inorganic part in predetermined amounts. The resultant mixture was utilized in the preparation of free films as well as coatings on aluminum substrates. Thermal and mechanical tests such as DSC, thermo-gravimetric analysis (TGA, and tensile and shore D hardness tests were performed on free films. Water contact angle, gloss, Taber abrasion test, cross-cut and tubular impact tests were conducted on the coated samples. SEM examination and EDS analysis was performed on the fractured surfaces of free films. The hybrid coatings on the aluminum sheets gave rise to properties such as moderately glossed surface; low wear rate and hydrophobicity. Tensile strength of free films increased with up to 10% inorganic content in the hybrid structure and this increase was approximately three times that of the control sample. As expected; the % strain value decreased by 17.3 with the increase in inorganic content and elastic modulus values increased by a factor of approximately 6. Resistance to ketone-based solvents was proven and an increase in hardness was observed as the ratio of the inorganic part increased. Samples which contain 10% sol–gel content were observed to provide optimal properties.

  11. Programmed Switching of Single Polymer Conformation on DNA Origami

    DEFF Research Database (Denmark)

    Krissanaprasit, Abhichart; Madsen, Mikael; Knudsen, Jakob Bach

    2016-01-01

    -molecule conjugated polymer. The polymer is functionalized with short single-stranded (ss) DNA strands that extend from the backbone of the polymer and serve as handles. The DNA polymer conjugate can be aligned on DNA origami in three well-defined geometries (straight line, left-turned, and right-turned pattern......) by DNA hybridization directed by single-stranded guiding strands and ssDNA tracks extending from the origami surface and polymer handle. We demonstrate switching of a conjugated organic polymer conformation between left- and right-turned conformations of the polymer on DNA origami based on toehold...

  12. A hybrid, massively parallel implementation of a genetic algorithm for optimization of the impact performance of a metal/polymer composite plate

    KAUST Repository

    Narayanan, Kiran

    2012-07-17

    A hybrid parallelization method composed of a coarse-grained genetic algorithm (GA) and fine-grained objective function evaluations is implemented on a heterogeneous computational resource consisting of 16 IBM Blue Gene/P racks, a single x86 cluster node and a high-performance file system. The GA iterator is coupled with a finite-element (FE) analysis code developed in house to facilitate computational steering in order to calculate the optimal impact velocities of a projectile colliding with a polyurea/structural steel composite plate. The FE code is capable of capturing adiabatic shear bands and strain localization, which are typically observed in high-velocity impact applications, and it includes several constitutive models of plasticity, viscoelasticity and viscoplasticity for metals and soft materials, which allow simulation of ductile fracture by void growth. A strong scaling study of the FE code was conducted to determine the optimum number of processes run in parallel. The relative efficiency of the hybrid, multi-level parallelization method is studied in order to determine the parameters for the parallelization. Optimal impact velocities of the projectile calculated using the proposed approach, are reported. © The Author(s) 2012.

  13. PHOTOREFRACTIVE POLYMERS

    NARCIS (Netherlands)

    Morichere, D; Malliaras, G.G; Krasnikov, V.V.; Bolink, H.J; Hadziioannou, G

    The use of polymers as photorefractive materials offers many advantages : flexibility in synthesis, doping, processing and low cost. The required functionalities responsible for photorefractivity, namely charge generation, transport, trapping and linear electrooptic effect are given in the polymer

  14. Photorefractive polymers

    NARCIS (Netherlands)

    Bolink, Hendrik Jan; Hadziioannou, G

    1997-01-01

    This thesis describes the synthesis and properties of photorefractive polymers. Photorefractive polymers are materials in which the refractive index can be varied by the interaction with light. Unlike in numerous other photosensitive materials, in photorefractive materials this occurs via

  15. Synthesis and characterization of a multifunctional inorganic-organic hybrid mixed-valence copper(I/II) coordination polymer: {[CuCN][Cu(isonic)2]}n

    Science.gov (United States)

    Liu, Dong-Sheng; Chen, Wen-Tong; Ye, Guang-Ming; Zhang, Jing; Sui, Yan

    2017-12-01

    A new multifunctional mixed-valence copper(I/II) coordination polymer, {[CuCN][Cu(isonic)2]}n(1) (Hisonic = isonicotinic acid), was synthesized by treating isonicotinic acid and 5-amino-tetrazolate (Hatz = 5-amino-tetrazolate) with copper(II) salts under hydrothermal conditions, and characterized by elemental analysis, infrared spectroscopy, and single crystal X-ray diffraction, respectively. The X-ray diffraction analysis reveals that compound exhibit noncentrosymmetric polar packing arrangement. It is three-dimensional (3D) framework with (3,5)-connected 'seh-3' topological network constructed from metal organic framework {[Cu(isonic)2]}n and the inorganic linear chain{Cu(CN)}n subunits. A remarkable feature of 1 is the rhombic open channels that are occupied by a linear chain of {Cu(CN)}n. Impressively compound 1 displays not only a second harmonic generation (SHG) response, but also a ferroelectric behavior and magnetic properties.

  16. Encapsulation of Polymer Colloids in a Sol-Gel Matrix. Direct-Writing of Coassembling Organic-Inorganic Hybrid Photonic Crystals.

    Science.gov (United States)

    Mikosch, Annabel; Kuehne, Alexander J C

    2016-03-22

    The spontaneous self-assembly of polymer colloids into ordered arrangements provides a facile strategy for the creation of photonic crystals. However, these structures often suffer from defects and insufficient cohesion, which result in flaking and delamination from the substrate. A coassembly process has been developed for convective assembly, resulting in large-area encapsulated colloidal crystals. However, to generate patterns or discrete deposits in designated places, convective assembly is not suitable. Here we experimentally develop conditions for direct-writing of coassembling monodisperse dye-doped polystyrene particles with a sol-gel precursor to form solid encapsulated photonic crystals. In a simple procedure the colloids are formulated in a sol-gel precursor solution, drop-cast on a flat substrate, and dried. We here establish the optimal parameters to form reproducible highly ordered photonic crystals with good optical performance. The obtained photonic crystals interact with light in the visible spectrum with a narrow optical stop-gap.

  17. Hybrid inorganic-organic polymer electrolytes: synthesis, FT-Raman studies and conductivity of {l_brace}Zr[(CH{sub 2}CH{sub 2}O){sub 8.7}]{sub {rho}}/(LiClO{sub 4}){sub z}{r_brace}{sub n} network complexes

    Energy Technology Data Exchange (ETDEWEB)

    Di Noto, Vito; Zago, Vanni; Biscazzo, Simone; Vittadello, Michele

    2003-01-15

    This paper describes the synthesis and characterization of three-dimensional hybrid inorganic-organic networks prepared by a polycondensation reaction between Zr(O(CH{sub 2}){sub 3}CH{sub 3}){sub 4} and polyethylene glycol 400 (PEG400). Eleven hybrid networks doped with varying concentrations of LiClO{sub 4} salt were prepared. On the basis of analytical data and FT-Raman studies it was concluded that these polymer electrolytes consist of inorganic-organic networks with zirconium atoms bonded together by PEG400 bridges. These polymers are transparent with a solid rubber consistency and are very stable under inert atmosphere. Scanning electron microscopy revealed a smooth glassy surface. X-ray fluorescence microanalysis with energy dispersive spectroscopy demonstrated that all the constituent elements are homogeneously distributed in the materials. Thermogravimetric measurements revealed that these materials are thermally stable up to 262 deg. C. Differential Scanning Calorimetry measurements indicated that the glass transition temperature T{sub g} of these inorganic-organic hybrids varies from -43 to -15 deg. C with increasing LiClO{sub 4} concentration. FT-Raman investigations revealed the TGT (T=trans, G=gauche) conformation of polyether chains and allowed characterization of the types of ion-ion and ion-polymer host interactions in the bulk materials. The conductivity of the materials at different temperatures was determined by impedance spectroscopy over the 20 Hz-1 MHz frequency range. Results indicated that the materials conduct ionically and that their ionic conductivity is strongly influenced by the segmental motion of the polymer network and the type of ionic species distributed in the bulk material. Finally, it is to be highlighted that the hybrid network with a n{sub Li}/n{sub O} molar ratio of 0.0223 shows a conductivity of ca. 1x10{sup -5} S cm{sup -1} at 40 deg. C.

  18. Preparation of dual-responsive hybrid fluorescent nano probe based on graphene oxide and boronic acid/BODIPY-conjugated polymer for cell imaging

    Energy Technology Data Exchange (ETDEWEB)

    Khoerunnisa [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Kang, Eun Bi [Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Mazrad, Zihnil Adha Islamy [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Lee, Gibaek [Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); In, Insik [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Department of Polymer Science and Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Park, Sung Young, E-mail: parkchem@ut.ac.kr [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of)

    2017-02-01

    Here, we report a pH- and thermo-responsive fluorescent nanomaterial of functionalized reduced graphene oxide (rGO) with cross-linked polymer produced via catechol-boronate diol binding mechanism. When conjugated with the hydrophobic dye boron dipyrromethane (BODIPY), this material can act as a dual-responsive nanoplatform for cells imaging. 2-Chloro-3′,4′-dihydroxyacetophenone (CCDP)-quaternized-poly(dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) [C-PDN] was cross-linked with BODIPY and 4-chlorophenyl boronic acid (BA)-quaternized-poly(ethylene glycol)-g-poly(dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) [BB-PPDN]. The GO was then reduced by the catechol group in the cross-linked polymer to synthesize rGO nanoparticles, which able to stabilize the quenching mechanism. This nanoplatform exhibits intense fluorescence at acidic pH and low fluorescence at physiological pH. Confocal laser scanning microscopy (CLSM) images shows bright fluorescence at lysosomal pH and total quench at physiological pH. Therefore, we have successfully developed a promising sensitive bio-imaging probe for identifying cancer cells. - Graphical abstract: [BB-PPDN]-[C-PDN]/rGO nanoparticles with boronic acid-catechol cis-diol binding mechanism toward change in pH demonstrated good biocompatibility and effective quenching for cancer cell detection. - Highlights: • Dual responsive (pH- and thermo) fluorescent nano probe was proposed for cells imaging. • The mechanism was based on cis-diol binding mechanism of boronic acid and catechol. • Reduced graphene oxide was used as quencher on nano-platform. • Detection was controlled dependent on pH based on diol compound of boron chemistry.

  19. Polymer Directed Protein Assemblies

    Directory of Open Access Journals (Sweden)

    Patrick van Rijn

    2013-05-01

    Full Text Available Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e.g., virus particles. Viruses are a multi-protein assembly of which the morphology is dictated by poly-nucleotides namely RNA or DNA. This “biopolymer” directs the proteins and imposes limitations on the structure like the length or diameter of the particle. Not only do these bionanoparticles use polymer-directed self-assembly, also processes like amyloid formation are in a way a result of directed protein assembly by partial unfolded/misfolded biopolymers namely, polypeptides. The combination of proteins and synthetic polymers, inspired by the natural processes, are therefore regarded as a highly promising area of research. Directed protein assembly is versatile with respect to the possible interactions which brings together the protein and polymer, e.g., electrostatic, v.d. Waals forces or covalent conjugation, and possible combinations are numerous due to the large amounts of different polymers and proteins available. The protein-polymer interacting behavior and overall morphology is envisioned to aid in clarifying protein-protein interactions and are thought to entail some interesting new functions and properties which will ultimately lead to novel bio-hybrid materials.

  20. Polymer Brushes

    NARCIS (Netherlands)

    Vos, de W.M.; Kleijn, J.M.; Keizer, de A.; Cosgrove, T.; Cohen Stuart, M.A.

    2010-01-01

    A polymer brush can be defined as a dense array of polymers end-attached to an interface that stretch out into the surrounding medium. Polymer brushes have been investigated for the past 30 years and have shown to be an extremely useful tool to control interfacial properties. This review is intended

  1. Effect of the Volume Fraction of Jute Fiber on the Interlaminar Shear Stress and Tensile Behavior Characteristics of Hybrid Glass/Jute Fiber Reinforced Polymer Composite Bar for Concrete Structures

    Directory of Open Access Journals (Sweden)

    Chan-Gi Park

    2016-01-01

    Full Text Available Hybrid glass/jute fiber reinforced polymer (HGJFRP composite bars were manufactured for concrete structures, and their interlaminar shear stress and tensile performance were evaluated. HGJFRP composite bars were manufactured using a combination of pultrusion and braiding processes. Jute fiber was surface-treated with a silane coupling agent. The mixing ratio of the fiber to the vinyl ester used in the HGJFRP composite bars was 7 : 3. Jute fiber was used to replace glass fiber in proportions of 0, 30, 50, 70, and 100%. The interlaminar shear stress decreased as the proportion of jute fiber increased. Fractures appeared due to delamination between the surface-treated component and the main part of the HGJFRP composite bar. Tensile load-strain curves with 50% jute fiber exhibited linear behavior. With a jute fiber volume fraction of 70%, some plastic deformation occurred. A jute fiber mixing ratio of 100% resulted in a display of linear elastic brittle behavior from the fiber; however, when the surface of the fiber was coated with poly(vinyl acetate, following failure, the jute fiber exhibited partial load resistance. The tensile strength decreased as the jute fiber content increased; however, the tensile strength did not vary linearly with jute fiber content.

  2. Hybrid molecularly imprinted polymers synthesized with 3-aminopropyltriethoxysilane-methacrylic acid monomer for miniaturized solid-phase extraction: A new and economical sample preparation strategy for determination of acyclovir in urine.

    Science.gov (United States)

    Yan, Hongyuan; Wang, Mingyu; Han, Yehong; Qiao, Fengxia; Row, Kyung Ho

    2014-06-13

    The miniaturized molecularly imprinted solid-phase extraction (mini-MISPE) coupled with high-performance liquid chromatography was proposed for the determination of acyclovir in urine. 1.5-mL tapered plastic centrifuge tube filled with hybrid molecularly imprinted polymers (HMIPs) was used as the cartridge of mini-MISPE, and the HMIPs synthesized with 3-aminopropyltriethoxy silane-methacrylic acid as monomer exhibited good recognition and selectivity for acyclovir. Under the optimized condition, good linear calibration was obtained in a range of 0.5-15μgmL(-1) with the correlation coefficient of 0.9994, and the recoveries at three spiked levels were 91.6-103.3% in urine with the relative standard deviation (RSD) of ≤3.5%. Excellent intra-day and inter-day repeatability were achieved with RSD of ≤2.6% and 4.0% in three different concentrations. This method combined the advantages of HMIPs and mini-MISPE, and it could become an alternative tool for analyzing the residues of acyclovir in complex urine matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. High-performance hybrid (electrostatic double-layer and faradaic capacitor-based) polymer actuators incorporating nickel oxide and vapor-grown carbon nanofibers.

    Science.gov (United States)

    Terasawa, Naohiro; Asaka, Kinji

    2014-12-02

    The electrochemical and electromechanical properties of polymeric actuators prepared using nickel peroxide hydrate (NiO2·xH2O) or nickel peroxide anhydride (NiO2)/vapor-grown carbon nanofibers (VGCF)/ionic liquid (IL) electrodes were compared with actuators prepared using solely VGCFs or single-walled carbon nanotubes (SWCNTs) and an IL. The electrode in these actuator systems is equivalent to an electrochemical capacitor (EC) exhibiting both electrostatic double-layer capacitor (EDLC)- and faradaic capacitor (FC)-like behaviors. The capacitance of the metal oxide (NiO2·xH2O or NiO2)/VGCF/IL electrode is primarily attributable to the EDLC mechanism such that, at low frequencies, the strains exhibited by the NiO2·xH2O/VGCF/IL and NiO2/VGCF/IL actuators primarily result from the FC mechanism. The VGCFs in the NiO2·xH2O/VGCF/IL and NiO2/VGCF/IL actuators strengthen the EDLC mechanism and increase the electroconductivity of the devices. The mechanism underlying the functioning of the NiO2·xH2O/VGCF/IL actuator in which NiO2·xH2O/VGCF = 1.0 was found to be different from that of the devices produced using solely VGCFs or SWCNTs, which exhibited only the EDLC mechanism. In addition, it was found that both NiO2 and VGCFs are essential with regard to producing actuators that are capable of exhibiting strain levels greater than those of SWCNT-based polymer actuators and are thus suitable for practical applications. Furthermore, the frequency dependence of the displacement responses of the NiO2·xH2O/VGCF and NiO2/VGCF polymer actuators were successfully simulated using a double-layer charging kinetic model. This model, which accounted for the oxidization and reduction reactions of the metal oxide, can also be applied to SWCNT-based actuators. The results of electromechanical response simulations for the NiO2·xH2O/VGCF and NiO2/VGCF actuators predicted the strains at low frequencies as well as the time constants of the devices, confirming that the model is applicable

  4. Magnetic iron oxide nanoparticles (MIONs) cross-linked natural polymer-based hybrid gel beads: Controlled nano anti-TB drug delivery application.

    Science.gov (United States)

    Kesavan, Mookkandi Palsamy; Ayyanaar, Srinivasan; Vijayakumar, Vijayaparthasarathi; Dhaveethu Raja, Jeyaraj; Annaraj, Jamespandi; Sakthipandi, Kathiresan; Rajesh, Jegathalaprathaban

    2018-04-01

    The nanosized rifampicin (RIF) has been prepared to increase the solubility in aqueous solution, which leads to remarkable enhancement of its bioavailability and their convenient delivery system studied by newly produced nontoxic, biodegradable magnetic iron oxide nanoparticles (MIONs) cross-linked polyethylene glycol hybrid chitosan (mCS-PEG) gel beads. The functionalization of both nano RIF and mCS-PEG gel beads were studied using various spectroscopic and microscopic techniques. The size of prepared nano RIF was found to be 70.20 ± 3.50 nm. The mechanical stability and swelling ratio of the magnetic gel beads increased by the addition of PEG with a maximum swelling ratio of 38.67 ± 0.29 g/g. Interestingly, this magnetic gel bead has dual responsive assets in the nano drug delivery application (pH and the magnetic field). As we expected, magnetic gel beads show higher nano drug releasing efficacy at acidic medium (pH = 5.0) with maximum efficiency of 71.00 ± 0.87%. This efficacy may also be tuned by altering the external magnetic field and the weight percentage (wt%) of PEG. These results suggest that such a dual responsive magnetic gel beads can be used as a potential system in the nano drug delivery applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1039-1050, 2018. © 2017 Wiley Periodicals, Inc.

  5. Effect of water on the physical properties and carbon dioxide capture capacities of liquid-like Nanoparticle Organic Hybrid Materials and their corresponding polymers

    KAUST Repository

    Petit, Camille; Bhatnagar, Sonali; Park, Ah-Hyung Alissa

    2013-01-01

    Binary systems composed of liquid-like Nanoparticle Organic Hybrid Materials (NOHMs) and the secondary fluid (i.e., water) were prepared, and their thermal stabilities, densities, viscosities, and CO2 absorption capacities were investigated. Recent work has suggested NOHMs as an alternative CO2 capture media with interesting chemical and physical tunability. Anhydrous CO2 capture solvents often degrade when they are exposed to water, while flue gas generally contains about 8-16% water. Thus, this study was conducted to investigate the effect of water on the NOHMs' properties relevant to CO2 capture as well as the chemical and thermal stabilities of H2O-loaded NOHMs. It was found that water acted as an antisolvent of NOHMs, and therefore, caused a decreased CO2 capture capacity. On the other hand, the results indicated that while water did not affect the NOHMs' thermal stability, it significantly helped lowering their density and viscosity. In order to investigate the effect of intermolecular interactions among two fluids on the density and viscosity, the excess volumes and viscosity deviations were calculated and correlated with Redlich-Kister equations. The trends revealed the existence of strong intermolecular interactions between water molecules and the poly(ethlyne glycol) component of NOHMs, which may have caused the drastic decrease in the NOHMs' viscosity with the addition of water. © 2013 Elsevier Inc.

  6. Effect of water on the physical properties and carbon dioxide capture capacities of liquid-like Nanoparticle Organic Hybrid Materials and their corresponding polymers

    KAUST Repository

    Petit, Camille

    2013-10-01

    Binary systems composed of liquid-like Nanoparticle Organic Hybrid Materials (NOHMs) and the secondary fluid (i.e., water) were prepared, and their thermal stabilities, densities, viscosities, and CO2 absorption capacities were investigated. Recent work has suggested NOHMs as an alternative CO2 capture media with interesting chemical and physical tunability. Anhydrous CO2 capture solvents often degrade when they are exposed to water, while flue gas generally contains about 8-16% water. Thus, this study was conducted to investigate the effect of water on the NOHMs\\' properties relevant to CO2 capture as well as the chemical and thermal stabilities of H2O-loaded NOHMs. It was found that water acted as an antisolvent of NOHMs, and therefore, caused a decreased CO2 capture capacity. On the other hand, the results indicated that while water did not affect the NOHMs\\' thermal stability, it significantly helped lowering their density and viscosity. In order to investigate the effect of intermolecular interactions among two fluids on the density and viscosity, the excess volumes and viscosity deviations were calculated and correlated with Redlich-Kister equations. The trends revealed the existence of strong intermolecular interactions between water molecules and the poly(ethlyne glycol) component of NOHMs, which may have caused the drastic decrease in the NOHMs\\' viscosity with the addition of water. © 2013 Elsevier Inc.

  7. Hybrid particles and associated methods

    Science.gov (United States)

    Fox, Robert V; Rodriguez, Rene; Pak, Joshua J; Sun, Chivin

    2015-02-10

    Hybrid particles that comprise a coating surrounding a chalcopyrite material, the coating comprising a metal, a semiconductive material, or a polymer; a core comprising a chalcopyrite material and a shell comprising a functionalized chalcopyrite material, the shell enveloping the core; or a reaction product of a chalcopyrite material and at least one of a reagent, heat, and radiation. Methods of forming the hybrid particles are also disclosed.

  8. Looking for new hybrid polymer fillers: synthesis of nanosized α-type Zr(IV) organophosphonates through an unconventional topotactic anion exchange reaction.

    Science.gov (United States)

    Pica, Monica; Donnadio, Anna; Troni, Elisabetta; Capitani, Donatella; Casciola, Mario

    2013-07-01

    Gels of α-type zirconium(IV) phosphate alkylphosphonates, ZP(Cn)x, were prepared by reacting, at room temperature, propanol intercalated nanosized α-zirconium phosphate (α-ZrP) with propanol solutions of alkylphosphonic acids (H2Cn, n = number of carbon atoms in the alkyl chain = 4, 5, 6), with (H2Cn/Zr) molar ratios in the range 0.4-4.0. (31)P MAS NMR showed the presence of resonances due to the phosphate and phosphonate groups bonded to the Zr atoms mainly by three oxygen atoms, as in the α-type layer. The composition of the ZP(Cn)x materials, obtained by thermogravimetric analysis, ranges from x ≈ 0.2 to x ≈ 1.1. On the basis of the NMR data and of the analysis of the X-ray patterns of gels and powders, it is inferred that the ZP(Cn)x compounds have an α-type layered structure and that the reaction between α-ZrP and H2Cn is a topotactic anion exchange process. The evolution of the X-ray patterns during propanol deintercalation is consistent with a random distribution of the alkylphosphonate groups on the α-type layers which gives rise to porous pathways in the interlayer region. To test the possibility of using ZP(Cn)x as mechanical reinforcement of a polymer matrix, a starch membrane filled with 5 wt % ZP(C6)0.54 was prepared and characterized by stress-strain mechanical tests. Besides an excellent flexibility, this membrane exhibited a proportional increase of the Young's modulus by 230% in comparison with neat starch.

  9. Thermoresponsive AuNPs Stabilized by Pillararene-Containing Polymers.

    Science.gov (United States)

    Liao, Xiaojuan; Guo, Lei; Chang, Junxia; Liu, Sha; Xie, Meiran; Chen, Guosong

    2015-08-01

    Pillararene-containing thermoresponsive polymers are synthesized via reversible addition-fragmentation chain transfer polymerization using pillararene derivatives as the effective chain transfer agents for the first time. These polymers can self-assemble into micelles and form vesicles after guest molecules are added. Furthermore, such functional polymers can be further applied to prepare hybrid gold nanoparticles, which integrate the thermoresponsivity of polymers and molecular recognition of pillararenes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Inorganic polymers and materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sneddon, Larry G.

    2001-01-01

    This DOE-sponsored project was focused on the design, synthesis, characterization, and applications of new types of boron and silicon polymers with a goal of attaining processable precursors to advanced ceramic materials of technological importance. This work demonstrated a viable design strategy for the systematic formation of polymeric precursors to ceramics based on the controlled functionalization of preformed polymers with pendant groups of suitable compositions and crosslinking properties. Both the new dipentylamine-polyborazylene and pinacolborane-hydridopolysilazane polymers, unlike the parent polyborazylene and other polyborosilazanes, are stable as melts and can be easily spun into polymer fibers. Subsequent pyrolyses of these polymer fibers then provide excellent routes to BN and SiNCB ceramic fibers. The ease of synthesis of both polymer systems suggests new hybrid polymers with a range of substituents appended to polyborazylene or polysilazane backbones, as well as other types of preceramic polymers, should now be readily achieved, thereby allowing even greater control over polymer and ceramic properties. This control should now enable the systematic tailoring of the polymers and derived ceramics for use in different technological applications. Other major recent achievements include the development of new types of metal-catalyzed methods needed for the polymerization and modification of inorganic monomers and polymers, and the modification studies of polyvinylsiloxane and related polymers with substituents that enable the formation of single source precursors to high-strength, sintered SiC ceramics.

  11. Advanced Electroactive Single Crystal and Polymer Actuator Concepts for Passive Optics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — TRS Technologies proposes large stroke and high precision piezoelectric single crystal and electroactive polymer actuator concepts?HYBrid Actuation System (HYBAS)...

  12. Hybrid white organic light-emitting diodes combining blue-fluorescent polymer and red phosphorescent Pt(II) complexes as active layer

    Energy Technology Data Exchange (ETDEWEB)

    Germino, Jose Carlos; Faleiros, Marcelo Meira; Moraes, Emmanuel Santos; Atvars, Teresa Dib Zambon, E-mail: kakagermino@hotmail.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Domingues, Raquel Aparecida [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil); Quites, Fernando Junior [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil); Freitas, Jilian Nei de [Centro de Tecnologia da Informacao Renato Archer, Campinas, SP (Brazil)

    2016-07-01

    Full text: In this work we proposed a PFO composite with two salicylidene based Pt(II) coordination compounds, the [Pt(salophen)] and [Pt(sal-3,4-ben)] (red emitters), as emissive layer (EML) for Organic Light-emitting Diodes (OLEDs), combining a blue-fluorescent polymer (PFO) with red-phosphorescent Pt(II) coordination complexes in order to obtain an efficient white electroluminescent EML for WOLEDs application. Firstly, [Pt(salophen)] and [Pt(sal-3,4-ben)] were synthesized, purified and characterized by single crystal X-ray diffraction, yielding their respective expected molecular structures. The photoluminescence properties of the devices were evaluated by steady-state (electronic absorption and emission spectroscopies) and transient (fluorescence decays and TRES) measurements. It was observed the presence of non-radiative energy transfer processes between the PFO derivative and Pt(II) complexes. Posteriorly, the Pt(II) complexes were blended with PVK at 1% mol:mol ratio and OLEDs were made, leading to red-emitting devices with high color purity for the two coordination compounds. However, the two devices present low current efficiency values. In order to improve the electroluminescence properties of Pt(II) complexes PhOLEDs, PVK host was substituted by PFO at 0.5, 1.0 and 2.5% mol:mol ratios of complex and it was observed a great improvement of their optical-electronic properties in terms of luminance, voltage, current density and current efficiency in comparison to PVK composites or pure PFO devices. At 2.5% concentration, predominant bands of Pt(II) complexes were observed at low and high voltages. For the other concentrations, a different behavior was observed: the emission bands and device color were function of applied electrical field, exhibiting a red color at lower voltages (5 to 9V) and the PFO characteristic emission between 9 and 13V, leading to a white light emission at 13V. The best results were obtained for [Pt(sal-3,4-ben)] coordination compound

  13. Polymer Electrolytes

    Science.gov (United States)

    Hallinan, Daniel T.; Balsara, Nitash P.

    2013-07-01

    This review article covers applications in which polymer electrolytes are used: lithium batteries, fuel cells, and water desalination. The ideas of electrochemical potential, salt activity, and ion transport are presented in the context of these applications. Potential is defined, and we show how a cell potential measurement can be used to ascertain salt activity. The transport parameters needed to fully specify a binary electrolyte (salt + solvent) are presented. We define five fundamentally different types of homogeneous electrolytes: type I (classical liquid electrolytes), type II (gel electrolytes), type III (dry polymer electrolytes), type IV (dry single-ion-conducting polymer electrolytes), and type V (solvated single-ion-conducting polymer electrolytes). Typical values of transport parameters are provided for all types of electrolytes. Comparison among the values provides insight into the transport mechanisms occurring in polymer electrolytes. It is desirable to decouple the mechanical properties of polymer electrolyte membranes from the ionic conductivity. One way to accomplish this is through the development of microphase-separated polymers, wherein one of the microphases conducts ions while the other enhances the mechanical rigidity of the heterogeneous polymer electrolyte. We cover all three types of conducting polymer electrolyte phases (types III, IV, and V). We present a simple framework that relates the transport parameters of heterogeneous electrolytes to homogeneous analogs. We conclude by discussing electrochemical stability of electrolytes and the effects of water contamination because of their relevance to applications such as lithium ion batteries.

  14. Star Polymers.

    Science.gov (United States)

    Ren, Jing M; McKenzie, Thomas G; Fu, Qiang; Wong, Edgar H H; Xu, Jiangtao; An, Zesheng; Shanmugam, Sivaprakash; Davis, Thomas P; Boyer, Cyrille; Qiao, Greg G

    2016-06-22

    Recent advances in controlled/living polymerization techniques and highly efficient coupling chemistries have enabled the facile synthesis of complex polymer architectures with controlled dimensions and functionality. As an example, star polymers consist of many linear polymers fused at a central point with a large number of chain end functionalities. Owing to this exclusive structure, star polymers exhibit some remarkable characteristics and properties unattainable by simple linear polymers. Hence, they constitute a unique class of technologically important nanomaterials that have been utilized or are currently under audition for many applications in life sciences and nanotechnologies. This article first provides a comprehensive summary of synthetic strategies towards star polymers, then reviews the latest developments in the synthesis and characterization methods of star macromolecules, and lastly outlines emerging applications and current commercial use of star-shaped polymers. The aim of this work is to promote star polymer research, generate new avenues of scientific investigation, and provide contemporary perspectives on chemical innovation that may expedite the commercialization of new star nanomaterials. We envision in the not-too-distant future star polymers will play an increasingly important role in materials science and nanotechnology in both academic and industrial settings.

  15. Polymer chemistry (revised edition)

    International Nuclear Information System (INIS)

    Kim, Jae Mum

    1987-02-01

    This book deals with polymer chemistry, which is divided into fourteen chapters. The contents of this book are development of polymer chemistry, conception of polymer, measurement of polymer chemistry, conception of polymer, measurement of polymer, molecule structure of polymer, thermal prosperities of solid polymer, basic theory of polymerization, radical polymerization, ion polymerization, radical polymerization, copolymerization, polymerization by step-reaction, polymer reaction, crown polymer and inorganic polymer on classification and process of creation such as polymeric sulfur and carbon fiber.

  16. Conductive polymer/superconductor bilayer structures

    International Nuclear Information System (INIS)

    McDevitt, J.T.; Haupt, S.G.; Riley, D.R.; Zhao, J.; Grassi, J.; Lo, R.K.; Jones, C.

    1994-01-01

    The preparation of a hybrid conducting polymer/high-temperature superconductor device consisting of a polypyrrole-coated YBa 2 Cu 3 O 7-∂ microbridge is reported. Electrochemical techniques are exploited to alter the oxidation state of the polymer and, in doing so, it is found for the first time that superconductivity can be modulated in a controllable and reproducible fashion by a polymer layer. Whereas the neutral (insulating) polypyrrole only slightly influences the electrical properties of the underlying YBa 2 Cu 3 O 7-∂ film, the oxidized (conductive) polymer depresses Tc by up to 50K. In a similar fashion, the oxidation state of the polymer is found to modulate reversibly the magnitude of J c , the superconducting critical current. Thus, a new type of molecular switch for controlling superconductivity is demonstrated. Electrochemical, resistance vs. temperature, conact resistance, atomic force microscopy and scanning electron microscopy measurements are utilized to explore the polymer/superconductor interactions

  17. Polymer Nanocomposites

    Indian Academy of Sciences (India)

    methods for the synthesis of polymer nanocomposites. In this article we .... ers, raw materials recovery, drug delivery and anticorrosion .... region giving rise to dose-packed absorption bands called an IR ... using quaternary ammonium salts.

  18. BioArtificial polymers

    Science.gov (United States)

    Szałata, Kamila; Gumi, Tania

    2017-07-01

    Nowadays, the polymer science has impact in practically all life areas. Countless benefits coming from the usage of materials with high mechanical and chemical resistance, variety of functionalities and potentiality of modification drive to the development of new application fields. Novel approaches of combining these synthetic substances with biomolecules lead to obtain multifunctional hybrid conjugates which merge the bioactivity of natural component with outstanding properties of artificial polymer. Over the decades, an immense progress in bioartificial composites domain allowed to reach a high level of knowledge in terms of natural-like systems engineering, leading to diverse strategies of biomolecule immobilization. Together with different available options, including covalent and noncovalent attachment, come various challenges, related mainly with maintaining the biological activity of fixed molecules. Even though the amount of applications that achieve commercial status is still not substantial, and is expanding continuously in the disciplines like "smart materials," biosensors, delivery systems, nanoreactors and many others. A huge number of remarkable developments reported in the literature present a potential of bioartificial conjugates as a fabrics with highly controllable structure and multiple functionalities, serving as a powerful nanotechnological tool. This novel approach brings closer biologists, chemists and engineers, who sharing their effort and complementing the knowledge can revolutionize the field of bioartificial polymer science.

  19. Enhancement of polymer dye lasers by multifunctional photonic crystal lattice

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Xiao, Sanshui; Mortensen, Asger

    2009-01-01

    The light output of dye doped hybrid polymer band-edge lasers is increased more than 100 times by using a rectangular lattice photonic crystal, which provides both feedback and couples more pump light into the laser.......The light output of dye doped hybrid polymer band-edge lasers is increased more than 100 times by using a rectangular lattice photonic crystal, which provides both feedback and couples more pump light into the laser....

  20. Mechanical and tribological studies of polymer hybrid ...

    Indian Academy of Sciences (India)

    Administrator

    new materials which enhance optimal utilization of natural resources and particularly of renewable resources. .... The PM 100 is a bench- top model ... In particular, when being used in ... in the range of 3 : 10 and silica particle reinforced nano-.

  1. Conductive polymer switch for controlling superconductivity

    International Nuclear Information System (INIS)

    McDevitt, J.T.; Haupt, S.G.; Riley, D.R.; Zhao, J.; Grassi, J.; Lo, K.; Jones, C.

    1994-01-01

    The preparation of a hybrid conducting polymer/high-temperature superconductor device consisting of a polypyrrole coated YBa 2 Cu 3 O 7-σ microbridge is reported. Electrochemical techniques are exploited to alter the oxidation state of the polymer and, in doing so, it is found for the first time that superconductivity can be modulated in a controllable and reproducible fashion by a polymer layout. Whereas the neutral (insulating) polypyrrole only slightly influences the electrical properties of the underlying YBa 2 Cu 3 O 7-σ film, the oxidized (conductive) polymer depresses T c by up to 50K. In a similar fashion, the oxidation state of the polymer is found to reversibly modulate the magnitude of J c , the superconducting critical current. Thus, a new type of molecule switch for controlling superconductivity is demonstrated

  2. Polymer nanocomposites: polymer and particle dynamics

    KAUST Repository

    Kim, Daniel; Srivastava, Samanvaya; Narayanan, Suresh; Archer, Lynden A.

    2012-01-01

    Polymer nanocomposites containing nanoparticles smaller than the random coil size of their host polymer chains are known to exhibit unique properties, such as lower viscosity and glass transition temperature relative to the neat polymer melt. It has

  3. Antimocrobial Polymer

    Science.gov (United States)

    McDonald, William F.; Huang, Zhi-Heng; Wright, Stacy C.

    2005-09-06

    A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from quaternary ammonium compounds, gentian violet compounds, substituted or unsubstituted phenols, biguanide compounds, iodine compounds, and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A)3P wherein A is hydroxyalkyl; and the antimicrobial agent is chlorhexidine, dimethylchlorophenol, cetyl pyridinium chloride, gentian violet, triclosan, thymol, iodine, and mixtures thereof.

  4. Polymer electronics

    CERN Document Server

    Geoghegan, Mark

    2013-01-01

    Polymer electronics is the science behind many important new developments in technology, such as the flexible electronic display (e-ink) and many new developments in transistor technology. Solar cells, light-emitting diodes, and transistors are all areas where plastic electronics is likely to, or is already having, a serious impact on our daily lives. With polymer transistors and light-emitting diodes now being commercialised, there is a clear need for a pedagogic text thatdiscusses the subject in a clear and concise fashion suitable for senior undergraduate and graduate students. The content

  5. Hybrid dual gate ferroelectric memory for multilevel information storage

    KAUST Repository

    Khan, Yasser; Caraveo-Frescas, Jesus Alfonso; Alshareef, Husam N.

    2015-01-01

    Here, we report hybrid organic/inorganic ferroelectric memory with multilevel information storage using transparent p-type SnO semiconductor and ferroelectric P(VDF-TrFE) polymer. The dual gate devices include a top ferroelectric field

  6. Polymer physics

    CERN Document Server

    Gedde, Ulf W

    1999-01-01

    This book is the result of my teaching efforts during the last ten years at the Royal Institute of Technology. The purpose is to present the subject of polymer physics for undergraduate and graduate students, to focus the fundamental aspects of the subject and to show the link between experiments and theory. The intention is not to present a compilation of the currently available literature on the subject. Very few reference citations have thus been made. Each chapter has essentially the same structure: starling with an introduction, continuing with the actual subject, summarizing the chapter in 30D-500 words, and finally presenting problems and a list of relevant references for the reader. The solutions to the problems presented in Chapters 1-12 are given in Chapter 13. The theme of the book is essentially polymer science, with the exclusion of that part dealing directly with chemical reactions. The fundamentals in polymer science, including some basic polymer chemistry, are presented as an introduction in t...

  7. Antimicrobial polymers.

    Science.gov (United States)

    Jain, Anjali; Duvvuri, L Sailaja; Farah, Shady; Beyth, Nurit; Domb, Abraham J; Khan, Wahid

    2014-12-01

    Better health is basic requirement of human being, but the rapid growth of harmful pathogens and their serious health effects pose a significant challenge to modern science. Infections by pathogenic microorganisms are of great concern in many fields such as medical devices, drugs, hospital surfaces/furniture, dental restoration, surgery equipment, health care products, and hygienic applications (e.g., water purification systems, textiles, food packaging and storage, major or domestic appliances etc.) Antimicrobial polymers are the materials having the capability to kill/inhibit the growth of microbes on their surface or surrounding environment. Recently, they gained considerable interest for both academic research and industry and were found to be better than their small molecular counterparts in terms of enhanced efficacy, reduced toxicity, minimized environmental problems, resistance, and prolonged lifetime. Hence, efforts have focused on the development of antimicrobial polymers with all desired characters for optimum activity. In this Review, an overview of different antimicrobial polymers, their mechanism of action, factors affecting antimicrobial activity, and application in various fields are given. Recent advances and the current clinical status of these polymers are also discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Polymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Naik, Sanjeev

    2017-08-22

    The present invention provides, among other things, extruded blends of aliphatic polycarbonates and polyolefins. In one aspect, provided blends comprise aliphatic polycarbonates such as poly(propylene carbonate) and a lesser amount of a crystalline or semicrystalline polymer. In certain embodiments, provided blends are characterized in that they exhibit unexpected improvements in their elongation properties. In another aspect, the invention provides methods of making such materials and applications of the materials in applications such as the manufacture of consumer packaging materials.

  9. Stratified polymer brushes from microcontact printing of polydopamine initiator on polymer brush surfaces.

    Science.gov (United States)

    Wei, Qiangbing; Yu, Bo; Wang, Xiaolong; Zhou, Feng

    2014-06-01

    Stratified polymer brushes are fabricated using microcontact printing (μCP) of initiator integrated polydopamine (PDOPBr) on polymer brush surfaces and the following surface initiated atom transfer radical polymerization (SI-ATRP). It is found that the surface energy, chemically active groups, and the antifouling ability of the polymer brushes affect transfer efficiency and adhesive stability of the polydopamine film. The stickiness of the PDOPBr pattern on polymer brush surfaces is stable enough to perform continuous μCP and SI-ATRP to prepare stratified polymer brushes with a 3D topography, which have broad applications in cell and protein patterning, biosensors, and hybrid surfaces. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Polyhedral Oligomeric Silsesquioxane (POSS)-Containing Polymer Nanocomposites

    Science.gov (United States)

    Ayandele, Ebunoluwa; Sarkar, Biswajit; Alexandridis, Paschalis

    2012-01-01

    Hybrid materials with superior structural and functional properties can be obtained by incorporating nanofillers into polymer matrices. Polyhedral oligomeric silsesquioxane (POSS) nanoparticles have attracted much attention recently due to their nanometer size, the ease of which these particles can be incorporated into polymeric materials and the unique capability to reinforce polymers. We review here the state of POSS-containing polymer nanocomposites. We discuss the influence of the incorporation of POSS into polymer matrices via chemical cross-linking or physical blending on the structure of nanocomposites, as affected by surface functional groups, and the POSS concentration. PMID:28348318

  11. Organometallic-inorganic hybrid electrodes for lithium-ion batteries

    Science.gov (United States)

    Huang, Qian; Lemmon, John P.; Choi, Daiwon; Cosimbescu, Lelia

    2016-09-13

    Disclosed are embodiments of active materials for organometallic and organometallic-inorganic hybrid electrodes and particularly active materials for organometallic and organometallic-inorganic hybrid cathodes for lithium-ion batteries. In certain embodiments the organometallic material comprises a ferrocene polymer.

  12. Hybrid reactors

    International Nuclear Information System (INIS)

    Moir, R.W.

    1980-01-01

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of 233 U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m -2 , and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid

  13. Methodological comparison on hybrid nano organic solar cell fabrication

    Science.gov (United States)

    Vairavan, Rajendaran; Hambali, Nor Azura Malini Ahmad; Wahid, Mohamad Halim Abd; Retnasamy, Vithyacharan; Shahimin, Mukhzeer Mohamad

    2018-02-01

    The development of low cost solar cells has been the main focus in recent years. This has lead to the generation of photovoltaic cells based on hybrid of nanoparticle-organic polymer materials. This type of hybrid photovoltaic cells can overcome the problem of polymeric devices having low optical absorption and carrier mobilities. The hybrid cell has the potential of bridging the efficiency gap, which in present in organic and inorganic semiconductor materials. This project focuses on obtaining an hybrid active layer consisting of nanoparticles and organic polymer, to understand the parameter involved in obtaining this active layer and finally to investigate if the addition of nano particles in to the active layer could enhance the output of the hybrid solar cell. The hybrid active layer have will be deposited using the spin coating technique by using CdTe, CdS nano particles mixed with poly (2-methoxy,5-(2-ethyl-hexyloxy)-p-phenylvinylene)MEH-PPV.

  14. Asymmetric Hybrid Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chumanov, George [Clemson Univ., SC (United States)

    2015-11-05

    Hybrid Nanoparticles (AHNs) are rationally-designed multifunctional nanostructures and novel building blocks for the next generation of advanced materials and devices. Nanoscale materials attract considerable interest because of their unusual properties and potential for practical applications. Most of the activity in this field is focused on the synthesis of homogeneous nanoparticles from metals, metal oxides, semiconductors, and polymers. It is well recognized that properties of nanoparticles can be further enhanced if they are made as hybrid structures. This program is concerned with the synthesis, characterization, and application of such hybrid structures termed AHNs. AHNs are composed of a homogeneous core and several caps of different materials deposited on its surface (Fig. 1). Combined properties of the core and the caps as well as new properties that arise from core-cap and cap-cap interactions render AHNs multifunctional. In addition, specific chemical reactivity of the caps enables directional self-assembly of AHNs into complex architectures that are not possible with only spherical nanoparticles.

  15. Multifunctional hybrids for electromagnetic absorption

    International Nuclear Information System (INIS)

    Huynen, I.; Quievy, N.; Bailly, C.; Bollen, P.; Detrembleur, C.; Eggermont, S.; Molenberg, I.; Thomassin, J.M.; Urbanczyk, L.

    2011-01-01

    Highlights: → EM absorption requires low dielectric constant and ∼1 S/m electrical conductivity. → New hybrids were processed with CNT-filled polymer foam inserted in Al honeycomb. → The EM absorption in the GHz range is superior to any known material. → A closed form model is used to guide the design of the hybrid. → The architectured material is light with potential for thermal management. - Abstract: Electromagnetic (EM) interferences are ubiquitous in modern technologies and impact on the reliability of electronic devices and on living cells. Shielding by EM absorption, which is preferable over reflection in certain instances, requires combining a low dielectric constant with high electrical conductivity, which are antagonist properties in the world of materials. A novel class of hybrid materials for EM absorption in the gigahertz range has been developed based on a hierarchical architecture involving a metallic honeycomb filled with a carbon nanotube-reinforced polymer foam. The waveguide characteristics of the honeycomb combined with the performance of the foam lead to unexpectedly large EM power absorption over a wide frequency range, superior to any known material. The peak absorption frequency can be tuned by varying the shape of the honeycomb unit cell. A closed form model of the EM reflection and absorption provides a tool for the optimization of the hybrid. This designed material sets the stage for a new class of sandwich panels combining high EM absorption with mass efficiency, stiffness and thermal management.

  16. Polymers for electronic & photonic application

    CERN Document Server

    Wong, C P

    2013-01-01

    The most recent advances in the use of polymeric materials by the electronic industry can be found in Polymers for Electronic and Photonic Applications. This bookprovides in-depth coverage of photoresis for micro-lithography, microelectronic encapsulants and packaging, insulators, dielectrics for multichip packaging,electronic and photonic applications of polymeric materials, among many other topics. Intended for engineers and scientists who design, process, and manufacturemicroelectronic components, this book will also prove useful for hybrid and systems packaging managers who want to be info

  17. Natural polymers: an overview

    CSIR Research Space (South Africa)

    John, MJ

    2012-08-01

    Full Text Available The scarcity of natural polymers during the world war years led to the development of synthetic polymers like nylon, acrylic, neoprene, styrene-butadiene rubber (SBR) and polyethylene. The increasing popularity of synthetic polymers is partly due...

  18. Interface induced growth and transformation of polymer-conjugated proto-crystalline phases in aluminosilicate hybrids: a multiple-quantum 23Na-23Na MAS NMR correlation spectroscopy study

    Czech Academy of Sciences Publication Activity Database

    Brus, Jiří; Kobera, Libor; Urbanová, Martina; Doušová, B.; Lhotka, M.; Koloušek, D.; Kotek, Jiří; Čuba, P.; Czernek, Jiří; Dědeček, Jiří

    2016-01-01

    Roč. 32, č. 11 (2016), s. 2787-2797 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GA13-24155S; GA MŠk(CZ) LD14010; GA MŠk(CZ) LO1507 Grant - others:European Commission(XE) COST Action MP1202 HINT Institutional support: RVO:61389013 ; RVO:61388955 Keywords : aluminosilicate hybrids * hybrid geopolymers * interface Subject RIV: CD - Macromolecular Chemistry; CF - Physical ; Theoretical Chemistry (UFCH-W) Impact factor: 3.833, year: 2016

  19. Hybrid Micro-Electro-Mechanical Tunable Filter

    Science.gov (United States)

    2007-09-01

    and polymer hybrid actuator and applications as a tunable filter in telecom and in IR chemical detector,” in Micromachining and Microfabrication...consistently achieved. At this temperature, SU8 - SU-8 bonding withstood subsequent processing steps, resulting in a 57% bond yield and an overall 30

  20. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites was investigated by Kalaprasad et al [25].Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane...

  1. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  2. Optics Communications: Special issue on Polymer Photonics and Its Applications

    Science.gov (United States)

    Zhang, Ziyang; Pitwon, Richard C. A.; Feng, Jing

    2016-03-01

    In the last decade polymer photonics has witnessed a tremendous boost in research efforts and practical applications. Polymer materials can be engineered to exhibit unique optical and electrical properties. Extremely transparent and reliable passive optical polymers have been made commercially available and paved the ground for the development of various waveguide components. Advancement in the research activities regarding the synthesis of active polymers has enabled devices such as ultra-fast electro-optic modulators, efficient white light emitting diodes, broadband solar cells, flexible displays, and so on. The fabrication technology is not only fast and cost-effective, but also provides flexibility and broad compatibility with other semiconductor processing technologies. Reports show that polymers have been integrated in photonic platforms such as silicon-on-insulator (SOI), III-V semiconductors, and silica PLCs, and vice versa, photonic components made from a multitude of materials have been integrated, in a heterogeneous/hybrid manner, in polymer photonic platforms.

  3. Polymer dynamics from synthetic polymers to proteins

    Indian Academy of Sciences (India)

    Keywords. Polymer dynamics; reptation; domain dynamics biomolecules. Abstract. Starting from the standard model of polymer motion - the Rouse model - we briefly present some key experimental results on the mesoscopic dynamics of polymer systems. We touch the role of topological confinement as expressed in the ...

  4. Synthesis and characterisation of star polymer/silicon carbide nanocomposites

    International Nuclear Information System (INIS)

    Majewski, Peter; Choudhury, Namita Roy; Spori, Doris; Wohlfahrt, Ellen; Wohlschloegel, Markus

    2006-01-01

    A new type of composite material's preparation and property are reported in this paper. The composite was formed by solution blending a styrene ethylene butylenes (SEBS) star polymer with silicon carbide at various compositions. The composites were characterised using spectroscopic, microscopic and thermal techniques. Photo-acoustic Fourier transform infrared spectroscopy (PA-FT-IR) and transmission electron microscopy (TEM) results show that the SiC resides uniformly in the organic network. Thermogravimetric analysis (TGA) of the hybrid shows that the thermal stability of the composite is higher than that of the star polymer. The maximum decomposition temperature increases by 73 deg. C. Dynamic mechanical analysis (DMA) of the hybrid shows that the storage modulus of the star polymer increases after the composite formation, indicating the existence of thermodynamically stable SiC nanoparticles mostly in the micro-phase separated multiarm structure of the polymer

  5. Shape memory polymers

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Thomas S.; Bearinger, Jane P.

    2017-08-29

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  6. Shape memory polymers

    Science.gov (United States)

    Wilson, Thomas S.; Bearinger, Jane P.

    2015-06-09

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  7. Covalent organic polymer functionalization of activated carbon surfaces through acyl chloride for environmental clean-up

    DEFF Research Database (Denmark)

    Mines, Paul D.; Thirion, Damien; Uthuppu, Basil

    2017-01-01

    Nanoporous networks of covalent organic polymers (COPs) are successfully grafted on the surfaces of activated carbons, through a series of surface modification techniques, including acyl chloride formation by thionyl chloride. Hybrid composites of activated carbon functionalized with COPs exhibit...

  8. Modeling Polymers Containing Rod-Like Fillers: From Morphology to Mechanical Behavior

    National Research Council Canada - National Science Library

    Balazs, Anna

    2004-01-01

    ... ̂ Predict the macroscopic properties of the reinforced polymers In order to carry out these studies, we employed hybrid models that we recently developed to investigate both the dynamic and equilibrium...

  9. Gas Sensors Based on Electrodeposited Polymers

    Directory of Open Access Journals (Sweden)

    Boris Lakard

    2015-07-01

    Full Text Available Electrochemically deposited polymers, also called “synthetic metals”, have emerged as potential candidates for chemical sensing due to their interesting and tunable chemical, electrical, and structural properties. In particular, most of these polymers (including polypyrrole, polyaniline, polythiophene and their derivatives can be used as the sensitive layer of conductimetric gas sensors because of their conducting properties. An important advantage of polymer-based gas sensors is their efficiency at room temperature. This characteristic is interesting since most of the commercially-available sensors, usually based on metal oxides, work at high temperatures (300–400 °C. Consequently, polymer-based gas sensors are playing a growing role in the improvement of public health and environment control because they can lead to gas sensors operating with rapid detection, high sensitivity, small size, and specificity in atmospheric conditions. In this review, the recent advances in electrodeposited polymer-based gas sensors are summarized and discussed. It is shown that the sensing characteristics of electrodeposited polymers can be improved by chemical functionalization, nanostructuration, or mixing with other functional materials to form composites or hybrid materials.

  10. 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

  11. Organic-inorganic hybrid membranes in separation processes: a 10-year review

    Directory of Open Access Journals (Sweden)

    V. C. Souza

    2013-12-01

    Full Text Available In relation to some inorganic membranes, polymeric membranes have relatively low separation performance. However, the processing flexibility and low cost of polymers still make them highly attractive for many industrial separation applications. Polymer-inorganic hybrid membranes constitute an emerging research field and have been recently developed to improve the separation properties of polymer membranes because they possess properties of both organic and inorganic membranes such as good hydrophilicity, selectivity, permeability, mechanical strength, and thermal and chemical stability. The structures and processing of polymer-inorganic nanocomposite hybrid membranes, as well as their use in the fields of ultrafiltration, nanofiltration, pervaporation, gas separation and separation mechanism are reviewed.

  12. Polymer nanocomposites: polymer and particle dynamics

    KAUST Repository

    Kim, Daniel

    2012-01-01

    Polymer nanocomposites containing nanoparticles smaller than the random coil size of their host polymer chains are known to exhibit unique properties, such as lower viscosity and glass transition temperature relative to the neat polymer melt. It has been hypothesized that these unusual properties result from fast diffusion of the nanostructures in the host polymer, which facilitates polymer chain relaxation by constraint release and other processes. In this study, the effects of addition of sterically stabilized inorganic nanoparticles to entangled cis-1,4-polyisoprene and polydimethylsiloxane on the overall rheology of nanocomposites are discussed. In addition, insights about the relaxation of the host polymer chains and transport properties of nanoparticles in entangled polymer nanocomposites are presented. The nanoparticles are found to act as effective plasticizers for their entangled linear hosts, and below a critical, chemistry and molecular-weight dependent particle volume fraction, lead to reduced viscosity, glass transition temperature, number of entanglements, and polymer relaxation time. We also find that the particle motions in the polymer host are hyperdiffusive and at the nanoparticle length scale, the polymer host acts like a simple, ideal fluid and the composites\\' viscosity rises with increasing particle concentration. © 2012 The Royal Society of Chemistry.

  13. Hybrid stars

    Indian Academy of Sciences (India)

    Hybrid stars. AsHOK GOYAL. Department of Physics and Astrophysics, University of Delhi, Delhi 110 007, India. Abstract. Recently there have been important developments in the determination of neutron ... number and the electric charge. ... available to the system to rearrange concentration of charges for a given fraction of.

  14. Influence of acceptor on charge mobility in stacked π-conjugated polymers

    Science.gov (United States)

    Sun, Shih-Jye; Menšík, Miroslav; Toman, Petr; Gagliardi, Alessio; Král, Karel

    2018-02-01

    We present a quantum molecular model to calculate mobility of π-stacked P3HT polymer layers with electron acceptor dopants coupled next to side groups in random position with respect to the linear chain. The hole density, the acceptor LUMO energy and the hybridization transfer integral between the acceptor and polymer were found to be very critical factors to the final hole mobility. For a dopant LUMO energy close and high above the top of the polymer valence band we have found a significant mobility increase with the hole concentration and with the dopant LUMO energy approaching the top of the polymer valence band. Higher mobility was achieved for small values of hybridization transfer integral between polymer and the acceptor, corresponding to the case of weakly bound acceptor. Strong couplings between the polymer and the acceptor with Coulomb repulsion interactions induced from the electron localizations was found to suppress the hole mobility.

  15. Photovoltaic cells and photodetectors made with semiconductor polymers: recent progress

    Science.gov (United States)

    Yu, Gang; Srdanov, Gordana; Wang, Hailiang; Cao, Yong; Heeger, Alan J.

    2000-05-01

    In this presentation, we discuss recent progress on polymer photovoltaic cells and polymer photodetectors. By improving the fill-factor of polymer photovoltaic cells, the energy conversion efficiency was improved significantly to over 4 percent. Such high efficiency polymer photovoltaic cells are promising for many applications including e-papers, e-books and smart-windows. Polymer photodetectors with similar device configuration show high photosensitivity, low dark current, large dynamic range, linear intensity dependence, low noise level and fast response time. These parameters are comparable to or even better than their inorganic counterparts. The advantages of low manufacturing cost, large detection area, and easy hybridization and integration with other electronic or optical components make them promising for a variety of applications including chemical/biomedical analysis, full-color digital image sensing and high energy radiation detection.

  16. Atomistic simulation of graphene-based polymer nanocomposites

    International Nuclear Information System (INIS)

    Rissanou, Anastassia N.; Bačová, Petra; Harmandaris, Vagelis

    2016-01-01

    Polymer/graphene nanostructured systems are hybrid materials which have attracted great attention the last years both for scientific and technological reasons. In the present work atomistic Molecular Dynamics simulations are performed for the study of graphene-based polymer nanocomposites composed of pristine, hydrogenated and carboxylated graphene sheets dispersed in polar (PEO) and nonpolar (PE) short polymer matrices (i.e., matrices containing chains of low molecular weight). Our focus is twofold; the one is the study of the structural and dynamical properties of short polymer chains and the way that they are affected by functionalized graphene sheets while the other is the effect of the polymer matrices on the behavior of graphene sheets.

  17. Electrospun nanocomposite fibrous polymer electrolyte for secondary lithium battery applications

    International Nuclear Information System (INIS)

    Padmaraj, O.; Rao, B. Nageswara; Jena, Paramananda; Satyanarayana, N.; Venkateswarlu, M.

    2014-01-01

    Hybrid nanocomposite [poly(vinylidene fluoride -co- hexafluoropropylene) (PVdF-co-HFP)/magnesium aluminate (MgAl 2 O 4 )] fibrous polymer membranes were prepared by electrospinning method. The prepared pure and nanocomposite fibrous polymer electrolyte membranes were soaked into the liquid electrolyte 1M LiPF 6 in EC: DEC (1:1,v/v). XRD and SEM are used to study the structural and morphological studies of nanocomposite electrospun fibrous polymer membranes. The nanocomposite fibrous polymer electrolyte membrane with 5 wt.% of MgAl 2 O 4 exhibits high ionic conductivity of 2.80 × 10 −3 S/cm at room temperature. The charge-discharge capacity of Li/LiCoO 2 coin cells composed of the newly prepared nanocomposite [(16 wt.%) PVdF-co-HFP+(5 wt.%) MgAl 2 O 4 ] fibrous polymer electrolyte membrane was also studied and compared with commercial Celgard separator

  18. 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.

  19. Paper actuators made with cellulose and hybrid materials.

    Science.gov (United States)

    Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad

    2010-01-01

    Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPap is quite comparable with other piezoelectric polymers. But, it is biodegradable, biocompatible, mechanically strong and thermally stable. To enhance ion migration effect in the cellulose, polypyrrole conducting polymer and ionic liquids were nanocoated on the cellulose film. This hybrid cellulose EAPap nanocomposite exhibits durable bending actuation in an ambient humidity and temperature condition. Fabrication, characteristics and performance of the cellulose EAPap and its hybrid EAPap materials are illustrated. Also, its possibility for remotely microwave-driven paper actuator is demonstrated.

  20. Tuning Structure and Properties of Graded Triblock Terpolymer-Based Mesoporous and Hybrid Films

    KAUST Repository

    Phillip, William A.; Mika Dorin, Rachel; Werner, Jörg; Hoek, Eric M. V.; Wiesner, Ulrich; Elimelech, Menachem

    2011-01-01

    -responsive, and contain pores with a nearly monodisperse diameter. These results suggest that moving to multiblock polymers and their hybrids may open new paths to produce high-performance graded membranes for filtration, separations, nanofluidics, catalysis, and drug

  1. 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 ...

  2. Electroluminescence from GaN-polymer heterojunction

    International Nuclear Information System (INIS)

    Chitara, Basant; Lal, Nidhi; Krupanidhi, S.B.; Rao, C.N.R.

    2011-01-01

    Inorganic and organic semiconductor devices are generally viewed as distinct and separate technologies. Herein we report a hybrid inorganic-organic light-emitting device employing the use of an air stable polymer, Poly (9,9-dioctylfluorene-alt-benzothiadiazole) as a p-type layer to create a heterojunction, avoiding the use of p-type GaN, which is difficult to grow, being prone to the complex and expensive fabrication techniques that characterises it. I-V characteristics of the GaN-polymer heterojunction fabricated by us exhibits excellent rectification. The luminescence onset voltage is typically about 8-10 V. The device emits yellowish white electroluminescence with CIE coordinates (0.42, 0.44). - Highlights: → We use a polymer Poly (9,9-dioctylfluorene-alt-benzothiadiazole) as a p-type layer to create a heterojunction. → I-V characteristics of the device fabricated by us exhibits excellent rectification. → The p-type polymer also emits yellow light, which when combined in proper composition with GaN, give rise to white light. → Device can be readily fabricated by just spin coating the polymer over GaN reducing the cost of the device.

  3. Cationic Antimicrobial Polymers and Their Assemblies

    Science.gov (United States)

    Carmona-Ribeiro, Ana Maria; de Melo Carrasco, Letícia Dias

    2013-01-01

    Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs). The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications. PMID:23665898

  4. Cationic Antimicrobial Polymers and Their Assemblies

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2013-05-01

    Full Text Available Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs. The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications.

  5. Hybrid Fiber Layup and Fiber-Reinforced Polymeric Composites Produced Therefrom

    Science.gov (United States)

    Barnell, Thomas J. (Inventor); Garrigan, Sean P. (Inventor); Rauscher, Michael D. (Inventor); Dietsch, Benjamin A. (Inventor); Cupp, Gary N. (Inventor)

    2018-01-01

    Embodiments of a hybrid fiber layup used to form a fiber-reinforced polymeric composite, and a fiber-reinforced polymeric composite produced therefrom are disclosed. The hybrid fiber layup comprises one or more dry fiber strips and one or more prepreg fiber strips arranged side by side within each layer, wherein the prepreg fiber strips comprise fiber material impregnated with polymer resin and the dry fiber strips comprise fiber material without impregnated polymer resin.

  6. Thermosetting Phthalocyanine Polymers

    Science.gov (United States)

    Fohlen, G.; Parker, J.; Achar, B.

    1985-01-01

    Group of phthalocyanine polymers resist thermal degradation. Polymers expected semiconducting. Principal applications probably in molded or laminated parts that have to withstand high temperatures. Polymers made from either of two classes of monomer: Bisphthalonitriles with imide linkages or Bisphthalonitriles with ester-imide linkages.

  7. based gel polymer electrolytes

    Indian Academy of Sciences (India)

    (PVdF) as a host polymer, lithium perchlorate (LiClO4), lithium triflate ... TG/DTA studies showed the thermal stability of the polymer electrolytes. .... are observed while comparing pure XRD spectra with .... batteries as its operating temperature is normally in the .... chain ion movements and the conductivity of the polymer.

  8. 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.

  9. Separation of Armchair SWNTs by Using Polymer Conformation Guided Assembly

    Science.gov (United States)

    2013-08-22

    Chan-Park, M. B. Diameter- and Metallicity-Selective Enrichment of Single-Walled Carbon Nanotubes Using Polymethacrylates with Pendant Aromatic...Emitting PPE-PPV Hybrid Polymers: Efficient Energy Transfer across the m-Phenylene Bridge . Macromolecules 2003, 36, 3848-3853. 34. Yao, J.; Chen, Y

  10. Polymer photonic crystal dye lasers as optofluidic cell sensors

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Lopacinska, Joanna M.; Jakobsen, Mogens Havsteen

    2009-01-01

    Dye doped hybrid polymer lasers are implemented as label free evanescent field biosensors for detection of cells. It is demonstrated that although the coverage is irregular and the cells extend over several lattice constants, the emission wavelength depends linearly on the fraction of the surface...

  11. The interplay of nanostructure and efficiency of polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chunhong, Yin

    2008-12-04

    The aim of this thesis is to achieve a deep understanding of the working mechanism of polymer based solar cells and to improve the device performance. Two types of the polymer based solar cells are studied here: the polymer-polymer solar cells, and the polymer-small molecule solar cell which has polymer as electron donor incorporating with organic small molecule as electron acceptor. For the polymer-polymer devices, I compared the photocurrent characteristics of bilayer and blend devices as well as the blend devices with different nano-morphology, which is fine tuned by applying solvents with different boiling points. The main conclusion based on the complementary measurements is that the performance-limiting step is the field-dependent generation of free charge carriers, while bimolecular recombination and charge extraction do not compromise device performance. Regarding polymer-small molecular hybrid solar cells I combined the hole-transporting polymer M3EH-PPV with a novel small molecule electron acceptor vinazene. This molecule can be either deposited from solution or by thermal evaporation, allowing for a large variety of layer architectures to be realized. I then demonstrated that the layer architecture has a large influence on the photovoltaic properties. Solar cells with very high fill factors of up to 57 % and an open circuit voltage of 1V without thermal treatment of the devices were achieved. In the past, fill factors of solar cells exceeding 50 % have only been observed when using fullerene-derivatives as the electron-acceptor. The finding that proper processing of polymer-vinazene devices leads to similar high values is a major step towards the design of efficient polymer-based solar cells. (orig.)

  12. Nanostructured polymer- and metal surfaces

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun

    , on wafer scale. The BSi structures were replicated into the UV curable organicinorganic hybrid polymer Ormocomp, in order to further assess the optical properties of the structures. BSi structures with lateral dimensions of around 1 μm would selectively scatter specific bands of wavelengths, resulting...... in a structural colour filter for specularly transmitted light. By reducing the height and lateral size, the structures enter a regime where scattering of visible light becomes insignificant. In this regime, the BSi structures were shown to be antireflective. An empirical relation between the characteristic...... moulding in polypropylene. A Ni shim was electroplated from a BSi master, and inserted in an injection moulding tool. The reflectance of the injection moulded parts was reduced from 4.5 % to 2.5% in the visible spectrum. The reflectance was calculated from the gradient in the refractive index from AFM data...

  13. Electroluminescence of Multicomponent Conjugated Polymers. 1. Roles of Polymer/Polymer Interfaces in Emission Enhancement and Voltage-Tunable Multicolor Emission in Semiconducting Polymer/Polymer Heterojunctions

    National Research Council Canada - National Science Library

    Zhang, Xuejun, Ph.D

    1999-01-01

    Effects of the electronic structure of polymer/polymer interfaces on the electroluminescence efficiency and tunable multicolor emission of polymer heterojunction light-emitting diodes were explored...

  14. Nanoporous polymer electrolyte

    Science.gov (United States)

    Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO

    2012-04-24

    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  15. Polymer friction Molecular Dynamics

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively...... independent of molecular length. For polymer sliding on polymer the friction is significantly larger, and dependent on the molecular chain length. In both cases, the shear stresses are proportional to the squeezing pressure and finite at zero load, indicating an adhesional contribution to the friction force....

  16. Biostable glucose permeable polymer

    DEFF Research Database (Denmark)

    2017-01-01

    A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

  17. Hybrid fiber and nanopowder reinforced composites for wind turbine blades

    Directory of Open Access Journals (Sweden)

    Nikoloz M. Chikhradze

    2015-01-01

    Full Text Available The results of an investigation into the production of wind turbine blades manufactured using polymer composites reinforced by hybrid (carbon, basalt, glass fibers and strengthened by various nanopowders (oxides, carbides, borides are presented. The hybrid fiber-reinforced composites (HFRC were manufactured with prepreg technology by molding pre-saturated epoxy-strengthened matrix-reinforced fabric. Performance of the manufactured composites was estimated with values of the coefficient of operating condition (COC at a moderate and elevated temperature.

  18. MODELLING OF CHARGE CARRIER MOBILITY FOR TRANSPORT BETWEEN ELASTIC POLYACETYLENE-LIKE POLYMER NANORODS

    Directory of Open Access Journals (Sweden)

    M. Mensik

    2017-03-01

    Full Text Available A quantum model solving the charge carrier mobility between polyacetylene-like polymer nanorods is presented. The model assumes: a Quantum mechanical calculation of hole on-chain delocalization involving electron-phonon coupling leading to the Peierls instability, b Hybridization coupling between the polymer backbone and side-groups (or environmental states, which act as hole traps, and c Semiclassical description of the inter-chain hole transfer in an applied voltage based on Marcus theory. We have found that mobility resonantly depends on the hybridization coupling between polymer and linked groups. We observed also non-trivial mobility dependences on the difference of energies of the highest occupied molecular orbitals localized on the polymer backbone and side-groups, respectively, and hole concentration. Those findings are important for optimization of hybrid opto-electronic devices.

  19. Fluorination of polymers

    International Nuclear Information System (INIS)

    Du Toit, F.J.

    1991-01-01

    Polyethylene and polypropylene were reacted with elemental fluorine under carefully controlled conditions to produce fluorocarbon polymers. Fluorination of polymer films resulted in fluorination of only the outer surfaces of the films, while the reaction of elemental fluorine with powdered hydrocarbon polymers produced perfluorocarbon polymers. Existing and newly developed techniques were used to characterize the fluorinated polymers. It was shown that the degree of fluorination was influenced by the surface area of the hydrocarbon material, the concentration, of the fluorine gas, and the time and temperature of fluorination. A fluidized-bed reactor used for the fluorination of polymer powders effectively increased the reaction rate. The surface tension and the oxygen permeability of the fluorinated polymers were studied. The surface tension of hydrocarbon polymers was not influenced by different solvents, but the surface tension of fluorinated polymers was affected by the type of solvent that was used. There were indications that the surface tension was affected by oxygen introduced into the polymer surface during fluorination. Fluorination lowered the permeability of oxygen through hydrocarbon polymers. 55 refs., 51 figs., 26 tabs

  20. Advanced polymers in medicine

    CERN Document Server

    Puoci, Francesco

    2014-01-01

    The book provides an up-to-date overview of the diverse medical applications of advanced polymers. The book opens by presenting important background information on polymer chemistry and physicochemical characterization of polymers. This serves as essential scientific support for the subsequent chapters, each of which is devoted to the applications of polymers in a particular medical specialty. The coverage is broad, encompassing orthopedics, ophthalmology, tissue engineering, surgery, dentistry, oncology, drug delivery, nephrology, wound dressing and healing, and cardiology. The development of polymers that enhance the biocompatibility of blood-contacting medical devices and the incorporation of polymers within biosensors are also addressed. This book is an excellent guide to the recent advances in polymeric biomaterials and bridges the gap between the research literature and standard textbooks on the applications of polymers in medicine.

  1. Antiviral Polymer Therapeutics

    DEFF Research Database (Denmark)

    Smith, Anton Allen Abbotsford

    2014-01-01

    polymerized in a controlled manner with carrier monomers of historically proven biocompatible polymers. The carrier polymers, the loading of ribavirin as well as the size of the polymer were varied systematically with the aid of an automated synthesis platform. These polymers were tested in a cellular assay...... of reversible-addition-fragmentation chain transfer polymerization, which not only controls the size of polymer, but also allows the introduction of a terminal amine on the polymer which can be used for further conjugation. This has allowed for not only fluorescent labeling of the polymer, but also protein...... is mediated through specific transporters, it is thought that the accumulation can be alleviated through the attachment of ribavirin to a macromolecule. To this end, ribavirin was enzymatically modified into a monomer compatible with controlled polymerization techniques. The ribavirin monomers were...

  2. Nanofibrous nonwovens based on dendritic-linear-dendritic poly(ethylene glycol) hybrids

    DEFF Research Database (Denmark)

    Kikionis, Stefanos; Ioannou, Efstathia; Andren, Oliver C.J.

    2017-01-01

    unsuccessful. Nevertheless, when these DLD hybrids were blended with an array of different biodegradable polymers as entanglement enhancers, nanofibrous nonwovens were successfully prepared by electrospinning. The pseudogeneration degree of the DLDs, the nature of the co-electrospun polymer and the solvent...... nanofibers. Such dendritic nanofibrous scaffolds can be promising materials for biomedical applications due to their biocompatibility, biodegradability, multifunctionality, and advanced structural architecture....

  3. Polymer reaction engineering, an integrated approach

    NARCIS (Netherlands)

    Meyer, T.; Keurentjes, J.T.F.; Meyer, T.; Keurentjes, J.T.F.

    2005-01-01

    Summary This chapter contains sections titled: Polymer Materials A Short History of Polymer Reaction Engineering The Position of Polymer Reaction Engineering Toward Integrated Polymer Reaction Engineering The Disciplines in Polymer Reaction Engineering The Future: Product-inspired Polymer Reaction

  4. Hybrid Filter Membrane

    Science.gov (United States)

    Laicer, Castro; Rasimick, Brian; Green, Zachary

    2012-01-01

    Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of

  5. Hybrid Qualifications

    DEFF Research Database (Denmark)

    Against the background of increasing qualification needs there is a growing awareness of the challenge to widen participation in processes of skill formation and competence development. At the same time, the issue of permeability between vocational education and training (VET) and general education...... has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...

  6. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  7. Dry Process for Manufacturing Hybridized Boron Fiber/Carbon Fiber Thermoplastic Composite Materials from a Solution Coated Precursor

    Science.gov (United States)

    Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor)

    2003-01-01

    An apparatus for producing a hybrid boron reinforced polymer matrix composite from precursor tape and a linear array of boron fibers. The boron fibers are applied onto the precursor tapes and the precursor tape processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the precursor tape with the boron fibers becomes a hybrid boron reinforced polymer matrix composite. A driving mechanism is used to pulled the precursor tape through the method and a take-up spool is used to collect the formed hybrid boron reinforced polymer matrix composite.

  8. Solid-state polymerisation via [2+2] cycloaddition reaction involving coordination polymers.

    Science.gov (United States)

    Medishetty, Raghavender; Park, In-Hyeok; Lee, Shim Sung; Vittal, Jagadese J

    2016-03-14

    Highly crystalline metal ions containing organic polymers are potentially useful to manipulate the magnetic and optical properties to make advanced multifunctional materials. However, it is challenging to synthesise monocrystalline metal complexes of organic polymers and single-phase hybrid materials made up of both coordination and organic polymers by traditional solution crystallisation. This requires an entirely different approach in the solid-state by thermal or photo polymerisation of the ligands. Among the photochemical methods available, [2+2] cycloaddition reaction has been recently employed to generate cyclobutane based coordination polymers from the metal complexes. Cyclobutane polymers have also been integrated into coordination polymers in this way. Recent advancements in the construction of polymeric chains of cyclobutane rings through photo-dimerisation reaction in the monocrystalline solids containing metal complexes, coordination polymers and metal-organic framework structures are discussed here.

  9. Stretchable and semitransparent conductive hybrid hydrogels for flexible supercapacitors.

    Science.gov (United States)

    Hao, Guang-Ping; Hippauf, Felix; Oschatz, Martin; Wisser, Florian M; Leifert, Annika; Nickel, Winfried; Mohamed-Noriega, Nasser; Zheng, Zhikun; Kaskel, Stefan

    2014-07-22

    Conductive polymers showing stretchable and transparent properties have received extensive attention due to their enormous potential in flexible electronic devices. Here, we demonstrate a facile and smart strategy for the preparation of structurally stretchable, electrically conductive, and optically semitransparent polyaniline-containing hybrid hydrogel networks as electrode, which show high-performances in supercapacitor application. Remarkably, the stability can extend up to 35,000 cycles at a high current density of 8 A/g, because of the combined structural advantages in terms of flexible polymer chains, highly interconnected pores, and excellent contact between the host and guest functional polymer phase.

  10. Carbon Nanotubes Hybrid Hydrogels in Drug Delivery: A Perspective Review

    Science.gov (United States)

    Hampel, Silke; Spizzirri, Umile Gianfranco; Parisi, Ortensia Ilaria; Picci, Nevio; Iemma, Francesca

    2014-01-01

    The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability) with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior). The applicability of polymer-carbon nanotubes composites in drug delivery, with particular attention to the controlled release by composites hydrogel, is being extensively investigated in the present review. PMID:24587993

  11. A paper-polymer centrifugal device for low-cost sample pre-concentration and colorimetric lateral flow assay enhancement

    CSIR Research Space (South Africa)

    Wiederoder, MS

    2016-10-01

    Full Text Available This study describes a novel hybrid paper-polymer centrifugal microfluidic device for pre-concentration of E.coli and lateral flow immunoassay enhancement for water quality verification. The device balances rotational centrifugal force...

  12. Intuitionistic hybrid logic

    DEFF Research Database (Denmark)

    Braüner, Torben

    2011-01-01

    Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area.......Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area....

  13. Star-Branched Polymers (Star Polymers)

    KAUST Repository

    Hirao, Akira; Hayashi, Mayumi; Ito, Shotaro; Goseki, Raita; Higashihara, Tomoya; Hadjichristidis, Nikolaos

    2015-01-01

    The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic

  14. Polymer dynamics from synthetic polymers to proteins

    Indian Academy of Sciences (India)

    Abstract. Starting from the standard model of polymer motion – the Rouse model – .... reptation and the escape processes (creep motion) from the tube. .... scattering curves from an arrangement of small mesoscopic spheres also allows a.

  15. Surface functionalization of quantum dots with fine-structured pH-sensitive phospholipid polymer chains.

    Science.gov (United States)

    Liu, Yihua; Inoue, Yuuki; Ishihara, Kazuhiko

    2015-11-01

    To add novel functionality to quantum dots (QDs), we synthesized water-soluble and pH-responsive block-type polymers by reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers were composed of cytocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer segments, which contain a small fraction of active ester groups and can be used to conjugate biologically active compounds to the polymer, and pH-responsive poly(2-(N,N-diethylamino) ethyl methacrylate (DEAEMA)) segments. One terminal of the polymer chain had a hydrophobic alkyl group that originated from the RAFT initiator. This hydrophobic group can bind to the hydrophobic layer on the QD surface. A fluorescent dye was conjugated to the polymer chains via the active ester group. The block-type polymers have an amphiphilic nature in aqueous medium. The polymers were thus easily bound to the QD surface upon evaporation of the solvent from a solution containing the block-type polymer and QDs, yielding QD/fluorescence dye-conjugated polymer hybrid nanoparticles. Fluorescence resonance energy transfer (FRET) between the QDs (donors) and the fluorescent dye molecules (acceptors) was used to obtain information on the conformational dynamics of the immobilized polymers. Higher FRET efficiency of the QD/fluorescent dye-conjugated polymer hybrid nanoparticles was observed at pH 7.4 as compared to pH 5.0 due to a stretching-shrinking conformational motion of the poly(DEAEMA) segments in response to changes in pH. We concluded that the block-type MPC polymer-modified nanoparticles could be used to evaluate the pH of cells via FRET fluorescence based on the cytocompatibility of the MPC polymer. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Star-Branched Polymers (Star Polymers)

    KAUST Repository

    Hirao, Akira

    2015-09-01

    The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic development of miktoarm star polymers since 2000. At the present time, the almost all types of multiarmed and multicomponent miktoarm star polymers have become feasible by using recently developed iterative strategy. For example, the following well-defined stars have been successfully synthesized: 3-arm ABC, 4-arm ABCD, 5-arm ABCDE, 6-arm ABCDEF, 7-arm ABCDEFG, 6-arm ABC, 9-arm ABC, 12-arm ABC, 13-arm ABCD, 9-arm AB, 17-arm AB, 33-arm AB, 7-arm ABC, 15-arm ABCD, and 31-arm ABCDE miktoarm star polymers, most of which are quite new and difficult to synthesize by the end of the 1990s. Several new specialty functional star polymers composed of vinyl polymer segments and rigid rodlike poly(acetylene) arms, helical polypeptide, or helical poly(hexyl isocyanate) arms are introduced.

  17. Performances Study of a Hybrid Rocket Engine

    Directory of Open Access Journals (Sweden)

    Adrian-Nicolae BUTURACHE

    2018-06-01

    Full Text Available This paper presents a study which analyses the functioning and performances optimization of a hybrid rocket engine based on gaseous oxygen and polybutadiene polymer (HTPB. Calculations were performed with NASA CEA software in order to obtain the parameters resulted following the combustion process. Using these parameters, the main parameters of the hybrid rocket engine were optimized. Using the calculus previously stated, an experimental rocket engine producing 100 N of thrust was pre-dimensioned, followed by an optimization of the rocket engine as a function of several parameters. Having the geometry and the main parameters of the hybrid rocket engine combustion process, numerical simulations were performed in the CFX – ANSYS commercial software, which allowed visualizing the flow field and the jet expansion. Finally, the analytical calculus was validated through numerical simulations.

  18. Artificially Engineered Protein Polymers.

    Science.gov (United States)

    Yang, Yun Jung; Holmberg, Angela L; Olsen, Bradley D

    2017-06-07

    Modern polymer science increasingly requires precise control over macromolecular structure and properties for engineering advanced materials and biomedical systems. The application of biological processes to design and synthesize artificial protein polymers offers a means for furthering macromolecular tunability, enabling polymers with dispersities of ∼1.0 and monomer-level sequence control. Taking inspiration from materials evolved in nature, scientists have created modular building blocks with simplified monomer sequences that replicate the function of natural systems. The corresponding protein engineering toolbox has enabled the systematic development of complex functional polymeric materials across areas as diverse as adhesives, responsive polymers, and medical materials. This review discusses the natural proteins that have inspired the development of key building blocks for protein polymer engineering and the function of these elements in material design. The prospects and progress for scalable commercialization of protein polymers are reviewed, discussing both technology needs and opportunities.

  19. Hybridized Tetraquarks

    CERN Document Server

    Esposito, A.; Polosa, A.D.

    2016-01-01

    We propose a new interpretation of the neutral and charged X, Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules. The latter would require a negative or zero binding energy whose counterpart in h-tetraquarks is a positive quantity. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs pi+- channel by the D0 collaboration and the negative result presented subsequently by the LHCb collaboration are understood in this scheme, together with a considerable portion of available data on X, Z particles. Considerations on a state with the same quantum numbers as the X(5568) are also made.

  20. Polymer Ferroelectric Memory for Flexible Electronics

    KAUST Repository

    Khan, Mohd Adnan

    2013-11-01

    trifluoroethylene) [P(VDF-TrFE)] and highly insulating dielectric poly(p-phenylene oxide) [PPO] with drastically improved fatigue and thermal stability; novel all-polymer ferroelectric diodes based on blends of ferroelectric [P(VDF-TrFE)] and n-type semiconducting [6,6]-phenyl-C61-butyric acid methyl ester [PCBM] with resistive switching properties and the first hybrid p-type ferroelectric memory with transparent tin monoxide [SnO] on plastic substrates with record mobilities.

  1. Polymer Ferroelectric Memory for Flexible Electronics

    KAUST Repository

    Khan, Mohd Adnan

    2013-01-01

    trifluoroethylene) [P(VDF-TrFE)] and highly insulating dielectric poly(p-phenylene oxide) [PPO] with drastically improved fatigue and thermal stability; novel all-polymer ferroelectric diodes based on blends of ferroelectric [P(VDF-TrFE)] and n-type semiconducting [6,6]-phenyl-C61-butyric acid methyl ester [PCBM] with resistive switching properties and the first hybrid p-type ferroelectric memory with transparent tin monoxide [SnO] on plastic substrates with record mobilities.

  2. Internally plasticised cellulose polymers

    International Nuclear Information System (INIS)

    Burnup, M.; Hayes, G.F.; Fydelor, P.J.

    1981-01-01

    Plasticised cellulose polymers comprise base polymer having a chain of β-anhydroglucose units joined by ether linkages, with at least one of said units carrying at least one chemically unreactive side chain derived from an allylic monomer or a vinyl substituted derivative of ferrocene. The side chains are normally formed by radiation grafting. These internally plasticised celluloses are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed. (author)

  3. A new class of tunable hypersonic phononic crystals based on polymer-tethered colloids.

    Science.gov (United States)

    Alonso-Redondo, E; Schmitt, M; Urbach, Z; Hui, C M; Sainidou, R; Rembert, P; Matyjaszewski, K; Bockstaller, M R; Fytas, G

    2015-09-22

    The design and engineering of hybrid materials exhibiting tailored phononic band gaps are fundamentally relevant to innovative material technologies in areas ranging from acoustics to thermo-optic devices. Phononic hybridization gaps, originating from the anti-crossing between local resonant and propagating modes, have attracted particular interest because of their relative robustness to structural disorder and the associated benefit to 'manufacturability'. Although hybridization gap materials are well known, their economic fabrication and efficient control of the gap frequency have remained elusive because of the limited property variability and expensive fabrication methodologies. Here we report a new strategy to realize hybridization gap materials by harnessing the 'anisotropic elasticity' across the particle-polymer interface in densely polymer-tethered colloidal particles. Theoretical and Brillouin scattering analysis confirm both the robustness to disorder and the tunability of the resulting hybridization gap and provide guidelines for the economic synthesis of new materials with deliberately controlled gap position and width frequencies.

  4. A new class of tunable hypersonic phononic crystals based on polymer-tethered colloids

    Science.gov (United States)

    Alonso-Redondo, E.; Schmitt, M.; Urbach, Z.; Hui, C. M.; Sainidou, R.; Rembert, P.; Matyjaszewski, K.; Bockstaller, M. R.; Fytas, G.

    2015-09-01

    The design and engineering of hybrid materials exhibiting tailored phononic band gaps are fundamentally relevant to innovative material technologies in areas ranging from acoustics to thermo-optic devices. Phononic hybridization gaps, originating from the anti-crossing between local resonant and propagating modes, have attracted particular interest because of their relative robustness to structural disorder and the associated benefit to `manufacturability'. Although hybridization gap materials are well known, their economic fabrication and efficient control of the gap frequency have remained elusive because of the limited property variability and expensive fabrication methodologies. Here we report a new strategy to realize hybridization gap materials by harnessing the `anisotropic elasticity' across the particle-polymer interface in densely polymer-tethered colloidal particles. Theoretical and Brillouin scattering analysis confirm both the robustness to disorder and the tunability of the resulting hybridization gap and provide guidelines for the economic synthesis of new materials with deliberately controlled gap position and width frequencies.

  5. Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Jordi Puiggalí

    2013-09-01

    Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  6. 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

  7. Study of PDMS conformation in PDMS-based hybrid materials prepared by gamma irradiation

    International Nuclear Information System (INIS)

    Lancastre, J.J.H.; Fernandes, N.; Margaça, F.M.A.; Miranda Salvado, I.M.; Ferreira, L.M.; Falcão, A.N.; Casimiro, M.H.

    2012-01-01

    Polydimethylsiloxane-silicate based hybrid materials have recognized properties (high flexibility, low elastic modulus or high mechanical strength) for which there are a large number of applications in development, such as for the bioapplications field. The hybrids addressed in the present study were prepared by gamma irradiation of a mixture of polydimethylsiloxane (PDMS) with tetraethylorthosilicate (TEOS) and zirconium propoxide (PrZr) without addition of any solvent or other product. The materials are homogeneous, transparent, monolithic and flexible. The structure dependence on the PrZr content is addressed. A combination of X-ray diffraction (XRD) and Infrared Spectroscopy (IR) was used. The results reveal that the polymer in the hybrids prepared with PrZr, in a content≤5 wt%, shows a structure similar to that in the irradiated pure polymer sample. In these samples the presence of ordered polymer regions is clearly found. For samples prepared with higher content of Zr almost no ordered polymer regions are observed. The addition of PrZr plays an important role on polymer conformation in these hybrid materials. - Highlights: ► PDMS-based hybrid materials were prepared by γ-irradiation. ► FTIR, ATR/FT-IR and XRD techniques were used to characterize the materials. ► Changes in FTIR bands reflect growth of crosslinking network. ► Above certain Zr concentration regions of Zr-silicate oxide are formed. ► Zr content determines conformation of the polymer chain network.

  8. Hybrid radical energy storage device and method of making

    Science.gov (United States)

    Gennett, Thomas; Ginley, David S; Braunecker, Wade; Ban, Chunmei; Owczarczyk, Zbyslaw

    2015-01-27

    Hybrid radical energy storage devices, such as batteries or electrochemical devices, and methods of use and making are disclosed. Also described herein are electrodes and electrolytes useful in energy storage devices, for example, radical polymer cathode materials and electrolytes for use in organic radical batteries.

  9. Shape-Memory Behavior of Polylactide/Silica Ionic Hybrids

    KAUST Repository

    Odent, Jérémy

    2017-03-27

    Commercial polylactide (PLA) was converted and endowed with shape-memory properties by synthesizing ionic hybrids based on blends of PLA with imidazolium-terminated PLA and poly[ε-caprolactone-co-d,l-lactide] (P[CL-co-LA]) and surface-modified silica nanoparticles. The electrostatic interactions assist with the silica nanoparticle dispersion in the polymer matrix. Since nanoparticle dispersion in polymers is a perennial challenge and has prevented nanocomposites from reaching their full potential in terms of performance we expect this new design will be exploited in other polymers systems to synthesize well-dispersed nanocomposites. Rheological measurements of the ionic hybrids are consistent with the formation of a network. The ionic hybrids are also much more deformable compared to the neat PLA. More importantly, they exhibit shape-memory behavior with fixity ratio Rf ≈ 100% and recovery ratio Rr = 79%, for the blend containing 25 wt % im-PLA and 25 wt % im-P[CL-co-LA] and 5 wt % of SiO2–SO3Na. Dielectric spectroscopy and dynamic mechanical analysis show a second, low-frequency relaxation attributed to strongly immobilized polymer chains on silica due to electrostatic interactions. Creep compliance tests further suggest that the ionic interactions prevent permanent slippage in the hybrids which is most likely responsible for the significant shape-memory behavior observed.

  10. Shape-Memory Behavior of Polylactide/Silica Ionic Hybrids

    KAUST Repository

    Odent, Jé ré my; Raquez, Jean-Marie; Samuel, Cé dric; Barrau, Sophie; Enotiadis, Apostolos; Dubois, Philippe; Giannelis, Emmanuel P.

    2017-01-01

    Commercial polylactide (PLA) was converted and endowed with shape-memory properties by synthesizing ionic hybrids based on blends of PLA with imidazolium-terminated PLA and poly[ε-caprolactone-co-d,l-lactide] (P[CL-co-LA]) and surface-modified silica nanoparticles. The electrostatic interactions assist with the silica nanoparticle dispersion in the polymer matrix. Since nanoparticle dispersion in polymers is a perennial challenge and has prevented nanocomposites from reaching their full potential in terms of performance we expect this new design will be exploited in other polymers systems to synthesize well-dispersed nanocomposites. Rheological measurements of the ionic hybrids are consistent with the formation of a network. The ionic hybrids are also much more deformable compared to the neat PLA. More importantly, they exhibit shape-memory behavior with fixity ratio Rf ≈ 100% and recovery ratio Rr = 79%, for the blend containing 25 wt % im-PLA and 25 wt % im-P[CL-co-LA] and 5 wt % of SiO2–SO3Na. Dielectric spectroscopy and dynamic mechanical analysis show a second, low-frequency relaxation attributed to strongly immobilized polymer chains on silica due to electrostatic interactions. Creep compliance tests further suggest that the ionic interactions prevent permanent slippage in the hybrids which is most likely responsible for the significant shape-memory behavior observed.

  11. Biomimetic synthesis of hybrid nanocomposite scaffolds by freeze

    Indian Academy of Sciences (India)

    The aim of this study is to biomimetically synthesize hydroxyapatite–hydrophilic polymer scaffolds for biomedical applications. This organic–inorganic hybrid has been structurally characterized and reveals a good microstructural control as seen by the SEM analysis and the nanosize of the particulates is confirmed by AFM ...

  12. Hybrid filler composition optimization for tensile strength of jute fibre

    Indian Academy of Sciences (India)

    https://www.ias.ac.in/article/fulltext/boms/039/05/1223-1231 ... The developed composite consists of natural jute fibre as reinforcement and unsaturated ... The effect of weight content of bagasse fibre, carbon black and calcium carbonate ... of pultruded jute fibre polymer composite at the optimum composition of hybrid filler.

  13. Hybrid materials of kaolinite clay with polypyrrole and polyaniline.

    Science.gov (United States)

    Burridge, Kerstin A; Johnston, James H; Borrmann, Thomas

    2009-12-01

    Composites of the alumino silicate mineral kaolinite, with the conducting polymers polypyrrole and polyaniline have been successfully synthesised. In doing so hybrid materials have been produced in which the high surface area of the mineral is retained, whilst also incorporating the desired chemical and physical properties of the polymer. Scanning electron microscopy shows polypyrrole coatings to comprise of individual polymer spheres, approximately 10 to 15 nm in diameter. The average size of the polymer spheres of polyaniline was observed to be approximately 5 nm in diameter. These spheres fuse together in a continuous sheet to coat the kaolinite platelets in their entirety. The reduction of silver ions to metallic silver nanoparticles onto the redox active surface of the polymers has also been successful, and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterization of the hybrid materials has been undertaken through scanning electron microscopy, energy dispersive spectroscopy, electrical conductivity, cyclic voltammetry, X-ray diffraction, infra red spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and the testing of their anti-microbial activity.

  14. Continuity controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation

  15. Continuity Controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  16. Continuity controlled hybrid automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  17. Continuity controlled hybrid automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2006-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  18. Binary Polymer Brushes of Strongly Immiscible Polymers.

    Science.gov (United States)

    Chu, Elza; Babar, Tashnia; Bruist, Michael F; Sidorenko, Alexander

    2015-06-17

    The phenomenon of microphase separation is an example of self-assembly in soft matter and has been observed in block copolymers (BCPs) and similar materials (i.e., supramolecular assemblies (SMAs) and homo/block copolymer blends (HBCs)). In this study, we use microphase separation to construct responsive polymer brushes that collapse to generate periodic surfaces. This is achieved by a chemical reaction between the minor block (10%, poly(4-vinylpyridine)) of the block copolymer and a substrate. The major block of polystyrene (PS) forms mosaic-like arrays of grafted patches that are 10-20 nm in size. Depending on the nature of the assembly (SMA, HBC, or neat BCP) and annealing method (exposure to vapors of different solvents or heating above the glass transition temperature), a range of "mosaic" brushes with different parameters can be obtained. Successive grafting of a secondary polymer (polyacrylamide, PAAm) results in the fabrication of binary polymer brushes (BPBs). Upon being exposed to specific selective solvents, BPBs may adopt different conformations. The surface tension and adhesion of the binary brush are governed by the polymer occupying the top stratum. The "mosaic" brush approach allows for a combination of strongly immiscible polymers in one brush. This facilitates substantial contrast in the surface properties upon switching, previously only possible for substrates composed of predetermined nanostructures. We also demonstrate a possible application of such PS/PAAm brushes in a tunable bioadhesion-bioadhesive (PS on top) or nonbioadhesive (PAAm on top) surface as revealed by Escherichia coli bacterial seeding.

  19. Performance estimation of photovoltaic–thermoelectric hybrid systems

    International Nuclear Information System (INIS)

    Zhang, Jin; Xuan, Yimin; Yang, Lili

    2014-01-01

    A theoretical model for evaluating the efficiency of concentrating PV–TE (photovoltaic–thermoelectric) hybrid system is developed in this paper. Hybrid systems with different photovoltaic cells are studied, including crystalline silicon photovoltaic cell, silicon thin-film photovoltaic cell, polymer photovoltaic cell and copper indium gallium selenide photovoltaic cell. The influence of temperature on the efficiency of photovoltaic cell has been taken into account based on the semiconductor equations, which reveals different efficiency temperature characteristic of polymer photovoltaic cells. It is demonstrated that the polycrystalline silicon thin-film photovoltaic cell is suitable for concentrating PV–TE hybrid system through optimization of the convection heat transfer coefficient and concentrating ratio. The polymer photovoltaic cell is proved to be suitable for non-concentrating PV–TE hybrid system. - Highlights: • Performances of four types of photovoltaic–thermoelectric hybrid systems are studied. • Temperature is one of dominant factors of affecting the conversion efficiency of PV–TE systems. • One can select a proper PV–TE assembly system according to given operating conditions

  20. Corporate Hybrid Bonds

    OpenAIRE

    Ahlberg, Johan; Jansson, Anton

    2016-01-01

    Hybrid securities do not constitute a new phenomenon in the Swedish capital markets. Most commonly, hybrids issued by Swedish real estate companies in recent years are preference shares. Corporate hybrid bonds on the other hand may be considered as somewhat of a new-born child in the family of hybrid instruments. These do, as all other hybrid securities, share some equity-like and some debt-like characteristics. Nevertheless, since 2013 the interest for the instrument has grown rapidly and ha...

  1. Polymer gels and networks

    National Research Council Canada - National Science Library

    Osada, Yoshihito; Khokhlov, A. R

    2002-01-01

    ... or magnetic field, etc.). It was realized that not only can polymer gels absorb and hold a considerable volume of liquids, but they can also be forced to expel the absorbed liquid in a controlled manner. Of particular interest are hydrogels, i.e., polymer gels, which swell extensively in water. The most common hydrogels are polyelectrolyte gels: ...

  2. SANS studies of polymers

    International Nuclear Information System (INIS)

    Wignall, G.D.

    1985-01-01

    Some information provided by the application of small-angle neutron scattering concerning polymer structure is reviewed herein. Information about the polymer structure as examined in H 2 O/D 2 O mixtures is also provided. Examples of results of experiments performed at the National Center for Small-Angle Scattering Research are included

  3. Polymer based tunneling sensor

    Science.gov (United States)

    Cui, Tianhong (Inventor); Wang, Jing (Inventor); Zhao, Yongjun (Inventor)

    2006-01-01

    A process for fabricating a polymer based circuit by the following steps. A mold of a design is formed through a lithography process. The design is transferred to a polymer substrate through a hot embossing process. A metal layer is then deposited over at least part of said design and at least one electrical lead is connected to said metal layer.

  4. Polymers for Combating Biocorrosion

    Directory of Open Access Journals (Sweden)

    Jing Guo

    2018-03-01

    Full Text Available Biocorrosion has been considered as big trouble in many industries and marine environments due to causing of great economic loss. The main disadvantages of present approaches to prevent corrosion include being limited by environmental factors, being expensive, inapplicable to field, and sometimes inefficient. Studies show that polymer coatings with anticorrosion and antimicrobial properties have been widely accepted as a novel and effective approach to prevent biocorrosion. The main purpose of this review is to summarize up the progressive status of polymer coatings used for combating microbial corrosion. Polymers used to synthesize protective coatings are generally divided into three categories: (i traditional polymers incorporated with biocides, (ii antibacterial polymers containing quaternary ammonium compounds, and (iii conductive polymers. The strategies to synthesize polymer coatings resort mainly to grafting antibacterial polymers from the metal substrate surface using novel surface-functionalization approaches, such as free radical polymerization, chemically oxidative polymerization, and surface-initiated atom transfer radical polymerization, as opposed to the traditional approaches of dip coating or spin coating.

  5. Polymer light emitting diodes

    International Nuclear Information System (INIS)

    Gautier-Thianche, Emmmanuelle

    1998-01-01

    We study sandwich type semiconducting polymer light emitting diodes; anode/polymer/cathode. ITO is selected as anode, this polymer is a blend of a commercially available polymer with a high hole transport ability: polyvinyl-carbazole and a laser dye: coumarin-515. Magnesium covered with silver is chosen for the anode. We study the influence of polymer thickness and coumarin doping ratio on electroluminescence spectrum, electric characteristics and quantum efficiency. An important drawback is that diodes lifetime remains low. In the second part of our study we determine degradations causes with X-Ray reflectivity experiments. It may be due to ITO very high roughness. We realize a new type of planar electroluminescent device: a channel type electroluminescent device in which polymer layer is inserted into an aluminium channel. Such a device is by far more stable than using classical sandwich structures with the same polymer composition: indeed, charges are generated by internal-field ionization and there is no injection from the electrode to the polymer. This avoids electrochemical reactions at electrodes, thus reducing degradations routes. (author) [fr

  6. Polymers targeting habitual diseases

    Science.gov (United States)

    The use of polymeric drug conjugates mainly for the treatment for cancer therapy has been addressed, but these polymers also find their way in treatment of various lifestyle disorders like diabetes, hypertension, cardiovascular diseases etc. The focus is being laid to develop biodegradable polymer ...

  7. Stiff quantum polymers

    OpenAIRE

    Kleinert, H.

    2009-01-01

    At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the second and fourth moments of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.

  8. Conducting polymer hydrogels

    Czech Academy of Sciences Publication Activity Database

    Stejskal, Jaroslav

    2017-01-01

    Roč. 71, č. 2 (2017), s. 269-291 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GA16-02787S Institutional support: RVO:61389013 Keywords : aerogel * conducting polymers * conductivity Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.258, year: 2016

  9. Hybrid XRF

    International Nuclear Information System (INIS)

    Heckel, J.

    2002-01-01

    Full text: In the last 10 years significant innovations of EDXRF, e.g. total reflection XRF or polarized beam XRF, were utilized in different industrial applications. The decrease of background within the spectra was the goal of these developments. Excellent detection limits and sensitivities demonstrate the success of these new techniques. Nevertheless, further improvements are possible by using Si drift detectors. These detectors allow the processing of input count rates up to 10 6 cps in comparison to 10 5 of Si(Li) detectors. New excitation optics are necessary to produce such count rates. One possibility is the use of doubly curved crystals between tube and sample. These crystals enable the reflection of the primary beam within the given solid angle (0.4π) of an end window tube to the sample. Using such brightness optics excellent sensitivities mainly for light elements are achievable. The combination of a BRAGG crystal as a wavelength dispersive component and a solid state detector as an energy dispersive component creates a new technique: hybrid XRF. Copyright (2002) Australian X-ray Analytical Association Inc. Copyright (2002) Australian X-ray Analytical Association Inc

  10. Shape Memory Composite Hybrid Hinge

    Science.gov (United States)

    Fang, Houfei; Im, Eastwood; Lin, John; Scarborough, Stephen

    2012-01-01

    There are two conventional types of hinges for in-space deployment applications. The first type is mechanically deploying hinges. A typical mechanically deploying hinge is usually composed of several tens of components. It is complicated, heavy, and bulky. More components imply higher deployment failure probability. Due to the existence of relatively moving components among a mechanically deploying hinge, it unavoidably has microdynamic problems. The second type of conventional hinge relies on strain energy for deployment. A tape-spring hinge is a typical strain energy hinge. A fundamental problem of a strain energy hinge is that its deployment dynamic is uncontrollable. Usually, its deployment is associated with a large impact, which is unacceptable for many space applications. Some damping technologies have been experimented with to reduce the impact, but they increased the risks of an unsuccessful deployment. Coalescing strain energy components with shape memory composite (SMC) components to form a hybrid hinge is the solution. SMCs are well suited for deployable structures. A SMC is created from a high-performance fiber and a shape memory polymer resin. When the resin is heated to above its glass transition temperature, the composite becomes flexible and can be folded or packed. Once cooled to below the glass transition temperature, the composite remains in the packed state. When the structure is ready to be deployed, the SMC component is reheated to above the glass transition temperature, and it returns to its as-fabricated shape. A hybrid hinge is composed of two strain energy flanges (also called tape-springs) and one SMC tube. Two folding lines are placed on the SMC tube to avoid excessive strain on the SMC during folding. Two adapters are used to connect the hybrid hinge to its adjacent structural components. While the SMC tube is heated to above its glass transition temperature, a hybrid hinge can be folded and stays at folded status after the temperature

  11. A novel hybrid metal-organic framework-polymeric monolith for solid-phase microextraction.

    Science.gov (United States)

    Lin, Chen-Lan; Lirio, Stephen; Chen, Ya-Ting; Lin, Chia-Her; Huang, Hsi-Ya

    2014-03-17

    This study describes the fabrication of a novel hybrid metal-organic framework- organic polymer (MOF-polymer) for use as a stationary phase in fritless solid-phase microextraction (SPME) for validating analytical methods. The MOF-polymer was prepared by using ethylene dimethacrylate (EDMA), butyl methacrylate (BMA), and an imidazolium-based ionic liquid as porogenic solvent followed by microwave-assisted polymerization with the addition of 25 % MOF. This novel hybrid MOF-polymer was used to extract penicillin (penicillin G, penicillin V, oxacillin, cloxacillin, nafcillin, dicloxacillin) under different conditions. Quantitative analysis of the extracted penicillin samples using the MOF-organic polymer for SPME was conducted by using capillary electrochromatography (CEC) coupled with UV analysis. The penicillin recovery was 63-96.2 % with high reproducibility, sensitivity, and reusability. The extraction time with the proposed fabricated SPME was only 34 min. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Organic / IV, III-V Semiconductor Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Pang-Leen Ong

    2010-03-01

    Full Text Available We present a review of the emerging class of hybrid solar cells based on organic-semiconductor (Group IV, III-V, nanocomposites, which states separately from dye synthesized, polymer-metal oxides and organic-inorganic (Group II-VI nanocomposite photovoltaics. The structure of such hybrid cell comprises of an organic active material (p-type deposited by coating, printing or spraying technique on the surface of bulk or nanostructured semiconductor (n-type forming a heterojunction between the two materials. Organic components include various photosensitive monomers (e.g., phtalocyanines or porphyrines, conjugated polymers, and carbon nanotubes. Mechanisms of the charge separation at the interface and their transport are discussed. Also, perspectives on the future development of such hybrid cells and comparative analysis with other classes of photovoltaics of third generation are presented.

  13. Optical and mechanical excitation thermography for impact response in basalt-carbon hybrid fiber-reinforced composite laminates

    OpenAIRE

    Zhang, Hai; Sfarra, Stefano; Sarasini, Fabrizio; Ibarra-Castanedo, Clemente; Perilli, Stefano; Fernandes, Henrique; Duan, Yuxia; Peeters, Jeroen; Avelidis, Nicholas P; Maldague, Xavier

    2017-01-01

    Abstract: In this paper, optical and mechanical excitation thermography were used to investigate basalt fiber reinforced polymer (BFRP), carbon fiber reinforced polymer (CFRP) and basalt-carbon fiber hybrid specimens subjected to impact loading. Interestingly, two different hybrid structures including sandwich-like and intercalated stacking sequence were used. Pulsed phase thermography (PPT), principal component thermography (PCT) and partial least squares thermography (PLST) were used to pro...

  14. Hybrid mimics and hybrid vigor in Arabidopsis

    Science.gov (United States)

    Wang, Li; Greaves, Ian K.; Groszmann, Michael; Wu, Li Min; Dennis, Elizabeth S.; Peacock, W. James

    2015-01-01

    F1 hybrids can outperform their parents in yield and vegetative biomass, features of hybrid vigor that form the basis of the hybrid seed industry. The yield advantage of the F1 is lost in the F2 and subsequent generations. In Arabidopsis, from F2 plants that have a F1-like phenotype, we have by recurrent selection produced pure breeding F5/F6 lines, hybrid mimics, in which the characteristics of the F1 hybrid are stabilized. These hybrid mimic lines, like the F1 hybrid, have larger leaves than the parent plant, and the leaves have increased photosynthetic cell numbers, and in some lines, increased size of cells, suggesting an increased supply of photosynthate. A comparison of the differentially expressed genes in the F1 hybrid with those of eight hybrid mimic lines identified metabolic pathways altered in both; these pathways include down-regulation of defense response pathways and altered abiotic response pathways. F6 hybrid mimic lines are mostly homozygous at each locus in the genome and yet retain the large F1-like phenotype. Many alleles in the F6 plants, when they are homozygous, have expression levels different to the level in the parent. We consider this altered expression to be a consequence of transregulation of genes from one parent by genes from the other parent. Transregulation could also arise from epigenetic modifications in the F1. The pure breeding hybrid mimics have been valuable in probing the mechanisms of hybrid vigor and may also prove to be useful hybrid vigor equivalents in agriculture. PMID:26283378

  15. Theory of polymer blends

    International Nuclear Information System (INIS)

    Curro, J.G.; Schweizer, K.S.

    1989-01-01

    We have recently developed a new theoretical approach to the study of polymer liquids. The theory is based on the ''reference interaction site model'' (RISM theory) of Chandler and Andersen, which has been successful in describing the structure of small molecule liquids. We have recently extended our polymer RISM theory to the case of polymer blends. In the present investigation we have applied this theory to two special binary blends: (1) the athermal mixture where we isolate structural effects, and (2) the isotopic mixture in which structurally identical polymer chains interact with dissimilar attractive interactions. By studying these two special cases we are able to obtain insights into the molecular factors which control the miscibility in polymer mixtures. 18 refs., 2 figs

  16. 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....

  17. All Polymer Micropump

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen

    2008-01-01

    In this thesis an all polymer micropump, and the fabrication method required to fabricate this, are examined. Polymer microfluidic. devices are of major scientific interest because they can combine complicated chemical and biological analys~s in cheap and disposable devices. The electrode system...... in the micropump is based on the conducting polymer poly(3,4 ethylenedioxythiophene) (PEDOT). The majority of the work conducted was therefore aimed at developing methods for patterning and processing PEDOT. First a method was developed, where the conducting polymer PEDOT can be integrated into non...... of the substrate, the PEDOT is integrated into the non-conductive polymer. The result is a material that retains the good conductivity of PEDOT, but gains the mechanical stability of the substrate. The best results were obtained for PEDOTjPMMA. The new mechanically stable PEDOTjPMMA was micro-patterned using clean...

  18. Polymer wear evaluation

    DEFF Research Database (Denmark)

    Lagerbon, Mikkel; Sivebæk, Ion Marius

    2012-01-01

    Polymer wear plays an increasing role in manufacturing of machine parts for e.g. medical devices. Some of these have an expected lifetime of five to eight years during which very little wear of the components is acceptable. Too much wear compromises the dosage accuracy of the device and thereby...... the safety of the patients. Prediction of the wear of polymers is complicated by the low thermal conductivity of this kind of material. It implies that any acceleration of testing conditions by increased contact pressure and/or sliding velocity will make the polymer fail due to exaggerated heat buildup....... This is not the kind of wear observed in medical devices. In the present work a method was developed capable of evaluating the wear progression in polymer-polymer contacts. The configuration of the setup is injection moulded specimens consisting of an upper part having a toroid shape and a lower flat part. The sliding...

  19. Preparation of silica-based hybrid materials by gamma irradiation

    International Nuclear Information System (INIS)

    Gomes, S.R.; Margaca, F.M.A.; Miranda Salvado, I.M.; Ferreira, L.M.; Falcao, A.N.

    2006-01-01

    Gamma-ray irradiation is well known to promote the crosslinking of polymer chains. The method is now used by the authors to prepare hybrid materials from a mixture of polymer and metallic alkoxides of silicium and zirconium that are usually obtained via the sol-gel process. Macroscopically homogeneous and transparent hybrid materials have been obtained by γ-irradiation of polydimethylsiloxane (PDMS), tetraethylorthosilicate (TEOS) and zirconium propoxide (PrZr). The influence of several parameters has been studied. The dose rate was found to have no significant impact in the prepared material. The polymer molecular weight was also observed not to play any special role. It was found that all irradiated samples consist of a polymer gel matrix. In the case where both alkoxides are present there are inorganic oxide regions linked to the PDMS network. However when one of the alkoxides is absent there is no formation of inorganic oxide regions linked to the polymer matrix, there being only a few individual derived molecules of the other alkoxide linked to the polymer

  20. Nitrogen-containing polymers as a platform for CO2 electroreduction.

    Science.gov (United States)

    Ponnurangam, Sathish; Chernyshova, Irina V; Somasundaran, Ponisseril

    2017-06-01

    Heterogeneous electroreduction of CO 2 has received considerable attention in the past decade. However, none of the earlier reviews has been dedicated to nitrogen-containing polymers (N-polymers) as an emerging platform for conversion of CO 2 to industrially useful chemicals. The term 'platform' is used here to underscore that the role of N-polymers is not only to serve as direct catalysts (through loaded metals) but also as co-catalysts/promoters and stabilizing agents. This review covers the current state, advantages, challenges, and prospects of the application of N-polymer-metal composites, also referred as polymer functionalized, coated, or modified electrodes, as well as functional hybrid materials, for the electrocatalytic conversion of CO 2 . It briefly surveys the efficiencies of the N-polymer-metal electrodes already used for this application, methods of their fabrication, and proposed mechanisms of their catalytic activities. Copyright © 2016 Elsevier B.V. All rights reserved.