WorldWideScience

Sample records for biocompatible polymeric materials

  1. Biocompatible Polymeric Materials Intended for Drug Delivery and Therapeutic Applications

    DEFF Research Database (Denmark)

    Hvilsted, Søren; Javakhishvili, Irakli; Bednarek, Melania;

    2007-01-01

    elucidating strategies for combination of biocompatible polymers in unique but amphiphilic manners. The targeted, documented biocompatible polymers like polycapro-lactone (PCL), poly(2-methoxyethyl acrylate)2 (PMEA) with the highest known blood compatibility, poly(methyl methacrylate) (PMMA), and the two...

  2. Polymeric barrier membranes for device packaging, diffusive control and biocompatibility

    International Nuclear Information System (INIS)

    Current state-of-the-art implantable micron feature electronic devices are capable of monitoring and stimulating functions in vivo. Within an EU Framework VI project a further step was taken in developing key microsystem technologies and communication methods that could bring intelligence directly to the human interface, in the form of reactive medical implants and ambulatory measurement systems. Information from these devices is planned to be transmitted out into the wider environment for remote processing. However, the packaging of such state-of-the-art devices to enhance tissue biocompatibility, and to protect conducting elements from in vivo corrosion during extended use, along with protecting the body from toxins leaching from implant components, remains a concern. Candidate polymeric barriers as hydration resistant and solute impermeable interfaces to mitigate such major problems of chronic implantation were investigated. Materials studied included silicone rubber, PVC, polyurethane, and diamond-like carbon (DLC). Polymer permeability to water solutes was marginally improved through incorporation of lipid into these structures. Surface biocompatibility was assessed on the basis of protein film deposition in vitro and by cell viability studies in tissue culture. Short-term toxicity was not observed for any of the tested materials, though there were substantial differences in hydration. Additionally, polypyrrole over active electrodes shows feasibility for controlled tissue interfacing whilst retaining electrical conductivity

  3. Conducting Polymeric Materials

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2016-01-01

    The overall objective of this collection is to provide the most recent developments within the various areas of conducting polymeric materials. The conductivity of polymeric materials is caused by electrically charged particles, ions, protons and electrons. Materials in which electrons are the ch...... awarded the Nobel Prize in chemistry “for the discovery and development of conductive polymers”....

  4. Initial biocompatibility of plasma polymerized hexamethyldisiloxane films with different wettability

    Energy Technology Data Exchange (ETDEWEB)

    Krasteva, N A; Toromanov, G; Hristova, K T; Radeva, E I; Pecheva, E V; Dimitrova, R P; Altankov, G P; Pramatarova, L D, E-mail: nataly@bio21.bas.b

    2010-11-01

    Understanding the relationships between material surface properties, behaviour of adsorbed proteins and cellular responses is essential to design optimal material surfaces for tissue engineering. In this study we modify thin layers of plasma polymerized hexamethyldisiloxane (PPHMDS) by ammonia treatment in order to increase surface wettability and the corresponding biological response. The physico-chemical properties of the polymer films were characterized by contact angle (CA) measurements and Fourier Transform Infrared Spectroscopy (FTIR) analysis.Human umbilical vein endothelial cells (HUVEC) were used as model system for the initial biocompatibility studies following their behavior upon preadsorption of polymer films with three adhesive proteins: fibronectin (FN), fibrinogen (FG) and vitronectin (VN). Adhesive interaction of HUVEC was evaluated after 2 hours by analyzing the overall cell morphology, and the organization of focal adhesion contacts and actin cytoskeleton. We have found similar good cellular response on FN and FG coated polymer films, with better pronounced vinculin expression on FN samples while. Conversely, on VN coated surfaces the wettability influenced significantly initial celular interaction spreading. The results obtained suggested that ammonia plasma treatment can modulate the biological activity of the adsorbed protein s on PPHMDS surfaces and thus to influence the interaction with endothelial cells.

  5. Applied bioactive polymeric materials

    CERN Document Server

    Carraher, Charles; Foster, Van

    1988-01-01

    The biological and biomedical applications of polymeric materials have increased greatly in the past few years. This book will detail some, but not all, of these recent developments. There would not be enough space in this book to cover, even lightly, all of the major advances that have occurred. Some earlier books and summaries are available by two of this book's Editors (Gebelein & Carraher) and these should be consul ted for additional information. The books are: "Bioactive Polymeric Systems" (Plenum, 1985); "Polymeric Materials In Medication" (Plenum, 1985); "Biological Acti vi ties of Polymers" (American Chemical Society, 1982). Of these three, "Bioacti ve Polymeric Systems" should be the most useful to a person who is new to this field because it only contains review articles written at an introductory level. The present book primarily consists of recent research results and applications, with only a few review or summary articles. Bioactive polymeric materials have existed from the creation of life...

  6. Plasma polymerized carvone as an antibacterial and biocompatible coating.

    Science.gov (United States)

    Chan, Yuen Wah; Siow, Kim Shyong; Ng, Pei Yuen; Gires, Usup; Yeop Majlis, Burhanuddin

    2016-11-01

    Antibacterial coating is important to prevent the colonization of medical devices by biofilm forming bacteria that would cause infection and sepsis in patients. Current coating techniques such as immobilization of antimicrobial compounds, time-releasing antibiotic agents and silver nanoparticles, require multiple processing steps, and they have low efficacy and low stability. We proposed a single-step plasma polymerization of an essential oil known as carvone to produce a moderately hydrophobic antibacterial coating (ppCar) with an average roughness of cell line. This study would be of interest to researcher keen on producing a bacteria-resistance and biocompatible coating on different substrates in a cost-effective manner. PMID:27524089

  7. Biocompatible post-polymerization functionalization of a water soluble poly(p-phenylene ethynylene)

    OpenAIRE

    Swager, Timothy Manning; Vanveller, Brett Steven

    2010-01-01

    A biocompatible post-polymerization functionalization reaction takes advantage of a polymer's structural motif for the controllable attachment of biotin as a model biosensor that responds to streptavidin.

  8. BIOCOMPATIBLE FLUORESCENT MICROSPHERES: SAFE PARTICLES FOR MATERIAL PENETRATION STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Farquar, G; Leif, R

    2009-07-15

    Biocompatible polymers with hydrolyzable chemical bonds have been used to produce safe, non-toxic fluorescent microspheres for material penetration studies. The selection of polymeric materials depends on both biocompatibility and processability, with tailored fluorescent properties depending on specific applications. Microspheres are composed of USFDA-approved biodegradable polymers and non-toxic fluorophores and are therefore suitable for tests where human exposure is possible. Micropheres were produced which contain unique fluorophores to enable discrimination from background aerosol particles. Characteristics that affect dispersion and adhesion can be modified depending on use. Several different microsphere preparation methods are possible, including the use of a vibrating orifice aerosol generator (VOAG), a Sono-Tek atomizer, an emulsion technique, and inkjet printhead. Applications for the fluorescent microspheres include challenges for biodefense system testing, calibrants for biofluorescence sensors, and particles for air dispersion model validation studies.

  9. Packaging based on polymeric materials

    OpenAIRE

    Jovanović Slobodan M.; Živković Predrag M.; Stoiljković Dragoslav M.

    2005-01-01

    In the past two years the consumption of common in the developed countries world wide (high tonnage) polymers for packaging has approached a value of 50 wt.%. In the same period more than 50% of the packaging units on the world market were made of polymeric materials despite the fact that polymeric materials present 17 wt.% of all packaging materials. The basic properties of polymeric materials and their environmental and economical advantages, providing them such a position among packaging m...

  10. Cycloolefin copolymer: new biocompatible material

    Czech Academy of Sciences Publication Activity Database

    Starý, Zdeněk; Kruliš, Zdeněk; Řihošková, V.; Petrtýl, M.

    Bratislava : Ústav polymérov, 2004. s. 126. [Slovensko-české dni o polyméroch /3./. 26.09.2004-29.09.2004, Smolenice] R&D Projects: GA ČR GA106/03/0255 Keywords : ultra high molecular weight polyethylene ( UHMWPE ) Subject RIV: JI - Composite Materials

  11. Electroactivity in Polymeric Materials

    CERN Document Server

    2012-01-01

    Electroactivity in Polymeric Materials provides an in-depth view of the theory of electroactivity and explores exactly how and why various electroactive phenomena occur. The book explains the theory behind electroactive bending (including ion-polymer-metal-composites –IPMCs), dielectric elastomers, electroactive contraction, and electroactive contraction-expansion cycles.  The book also balances theory with applications – how electroactivity can be used – drawing inspiration from the manmade mechanical world and the natural world around us.  This book captures: A complete introduction to electroactive materials including examples and recent developments The theory and applications of numerous topics like electroactive bending of dielectric elastomers and electroactive contraction and expansion New topics, such as biomimetic applications and energy harvesting This is a must-read within the electroactive community, particularly for professionals and graduate students who are interested in the ...

  12. Superparamagnetic microrobots: fabrication by two-photon polymerization and biocompatibility.

    Science.gov (United States)

    Suter, Marcel; Zhang, Li; Siringil, Erdem C; Peters, Christian; Luehmann, Tessa; Ergeneman, Olgac; Peyer, Kathrin E; Nelson, Bradley J; Hierold, Christofer

    2013-12-01

    This work presents the fabrication and controlled actuation of swimming microrobots made of a magnetic polymer composite (MPC) consisting of 11-nm-diameter magnetite (Fe3O4) nanoparticles and photocurable resin (SU-8). Two-photon polymerization (TPP) is used to fabricate the magnetic microstructures. The material properties and the cytotoxicity of the MPC with different nanoparticle concentrations are characterized. The live/dead staining tests indicate that MPC samples with varied concentrations, up to 10 vol.%, have negligible cytotoxicity after 24 h incubation. Fabrication parameters of MPC with up to 4 vol.% were investigated. We demonstrate that the helical microdevices made of 2 vol.% MPC were capable of performing corkscrew motion in water applying weak uniform rotating magnetic fields. PMID:23846247

  13. Microwave pyrolisis of polymeric materials

    OpenAIRE

    A.Undri; L.Rosi; M. FREDIANI; P. Frediani

    2011-01-01

    The polymeric materials consumption are growing ceaselessly in the world even in spite of the financial crisis. World rubber demand, for instance, is foreseen to increase up to 4% annually to 26.5 million metric tons in 2011. Therefore the disposal of waste polymers is a serious environmental problem against which public is becoming more aware. The interest of waste polymeric materials disposal is focused on new ways of dealing rather than land filling or incineration. The pyrolysis of polyme...

  14. [Biocompatibility of dental materials: Part 2. Materials with mucosal contact].

    Science.gov (United States)

    Klötzer, W T; Reuling, N

    1990-08-01

    Dental materials which are supposed to contact the oral, mucous membranes during their intended dental use may affect our patients health in different ways. Their local and systemic toxicity, and their allergenic and tumorigenic potential are reviewed and methods of biocompatibility testing discussed. Special emphasis is placed on impression materials, denture base resins and dental alloys. PMID:2269166

  15. Surface construction and biocompatibility of polymeric used for cardiovascular medical device○

    Institute of Scientific and Technical Information of China (English)

    Chen Bao-lin; Wang Dong-an

    2013-01-01

    BACKGROUND:Biomaterials for the treatment of cardiovascular diseases must have anti-thrombotic, anti-biodegradability and anti-infective ability in the blood-contact condition. OBJECTIVE:To investigate the biocompatibility, blood compatibility and cytocompatibility of new implantable (interfered) polymer material (surface) used in cardiovascular tissue engineering. METHODS:The PubMed database and Wanfang database were retrieved for the related articles from 1967 to 2012 with the key words of“biocompatibility, lood compatibility, biomedical materials, biomedical polymer materials”. RESUTLS AND CONCLUSION:The graft copolymer surface and a block copolymer surfactant that can be used as biological materials were in-depth analyzed though analyzing the design requirements of type, application, cardiovascular medical devices and implantable soft tissue substitutes of polymeric biomaterials used for cardiovascular medicine. The results showed that the difference between the surface and noumenon wil be reflected on many molecular layers that extended from the surface to the noumenon, while the two main factors of surface energy and molecular motion determined the noumenon/surface behavior including the noumenon/surface difference and surface phase separation. If the understanding of the noumenon/surface consisting difference should be taking into consideration, the other determinant should be added too, that was the crystal ization behavior of each competent. If the one of the components contained in the graft copolymer surface and a block copolymer surfactant had higher crystal inity, the other components wil be squeezed out;crystal ization could also hindered the motion and diffusion of molecules, and eventual y, the incompatibility degree of two components of copolymers wil affect the phase separation tendency in the noumenon and surface layers.

  16. Multicomponent polymeric materials

    CERN Document Server

    Thomas, Sabu; Saha, Prosenjit

    2016-01-01

    The book offers an in-depth review of the materials design and manufacturing processes employed in the development of multi-component or multiphase polymer material systems. This field has seen rapid growth in both academic and industrial research, as multiphase materials are increasingly replacing traditional single-component materials in commercial applications. Many obstacles can be overcome by processing and using multiphase materials in automobile, construction, aerospace, food processing, and other chemical industry applications. The comprehensive description of the processing, characterization, and application of multiphase materials presented in this book offers a world of new ideas and potential technological advantages for academics, researchers, students, and industrial manufacturers from diverse fields including rubber engineering, polymer chemistry, materials processing and chemical science. From the commercial point of view it will be of great value to those involved in processing, optimizing an...

  17. Material Biocompatibility for PCR Microfluidic Chips

    KAUST Repository

    Kodzius, Rimantas

    2010-04-23

    As part of the current miniaturization trend, biological reactions and processes are being adapted to microfluidics devices. PCR is the primary method employed in DNA amplification, its miniaturization is central to efforts to develop portable devices for diagnostics and testing purposes. A problem is the PCR-inhibitory effect due to interaction between PCR reagents and the surrounding environment, which effect is increased in high-surface-are-to-volume ration microfluidics. In this study, we evaluated the biocompatibility of various common materials employed in the fabrication of microfluidic chips, including silicon, several kinds of silicon oxide, glasses, plastics, wax, and adhesives. Two-temperature PCR was performed with these materials to determine their PCR-inhibitory effect. In most of the cases, addition of bovine serum albumin effectively improved the reaction yield. We also studied the individual PCR components from the standpoint of adsorption. Most of the materials did not inhibit the DNA, whereas they did show noticeable interaction with the DNA polymerase. Our test, instead of using microfluidic devices, can be easily conducted in common PCR tubes using a standard bench thermocycler. Our data supports an overview of the means by which the materials most bio-friendly to microfluidics can be selected.

  18. Polymeric materials for neovascularization

    Science.gov (United States)

    DeVolder, Ross John

    Revascularization therapies have emerged as a promising strategy to treat various acute and chronic wounds, cardiovascular diseases, and tissue defects. It is common to either administer proangiogenic growth factors, such as vascular endothelial growth factor (VEGF), or transplant cells that endogenously express multiple proangiogenic factors. Additionally, these strategies utilize a wide variety of polymeric systems, including hydrogels and biodegradable plastics, to deliver proangiogenic factors in a sophisticated manner to maintain a sustained proangiogenic environment. Despite some impressive results in rebuilding vascular networks, it is still a challenging task to engineer mature and functional neovessels in target tissues, because of the increasing complexities involved with neovascularization applications. To resolve these challenges, this work aims to design a wide variety of proangiogenic biomaterial systems with tunable properties used for neovascularization therapies. This thesis describes the design of several biomaterial systems used for the delivery of proangiogenic factors in neovascularization therapies, including: an electrospun/electrosprayed biodegradable plastic patch used for directional blood vessel growth (Chapter 2), an alginate-g-pyrrole hydrogel system that biochemically stimulates cellular endogenous proangiogenic factor expression (Chapter 3), an enzyme-catalyzed alginate-g-pyrrole hydrogel system for VEGF delivery (Chapter 4), an enzyme-activated alginate-g-pyrrole hydrogel system with systematically controllable electrical and mechanical properties (Chapter 5), and an alginate-g-pyrrole hydrogel that enables the decoupled control of electrical conductivity and mechanical rigidity and is use to electrically stimulate cellular endogenous proangiogenic factor expression (Chapter 6). Overall, the biomaterial systems developed in this thesis will be broadly useful for improving the quality of a wide array of molecular and cellular based

  19. Biocompatibility of Cation Coated on Plasma-Polymerized Ti Surface

    Science.gov (United States)

    Lee, Kang; Ko, Yeong-Mu; Kim, Byung-Hoon

    2012-08-01

    In this study, we investigated the bone formation properties and cell responses on Na-, Mg-, K-, and Ca-ion-exchanged carboxyl plasma polymerized titanium (Ti) surfaces. The phase and morphologies of deposits bonelike apatite were significantly influence by the cation species. Na and Mg ions promote bonelike apatite nucleation and growth on plasma-functionalized Ti surfaces in simulated body fluid (SBF) and improves the crystallinity of the bonelike apatite deposited layer. The cell viability tests revealed significantly enhanced viability on the Ca-ion-exchanged plasma-functionalized Ti surface than on any other surface.

  20. The Use of Nanoscaled Fibers or Tubes to Improve Biocompatibility and Bioactivity of Biomedical Materials

    Directory of Open Access Journals (Sweden)

    Xiaoming Li

    2013-01-01

    Full Text Available Nanofibers and nanotubes have recently gained substantial interest for potential applications in tissue engineering due to their large ratio of surface area to volume and unique microstructure. It has been well proved that the mechanical property of matrix could be largely enhanced by the addition of nanoscaled fibers or tubes. At present, more and more researches have shown that the biocompatibility and bioactivity of biomedical materials could be improved by the addition of nanofibers or nanotubes. In this review, the efforts using nanofibers and nanotubes to improve biocompatibility and bioactivity of biomedical materials, including polymeric nanofibers/nanotubes, metallic nanofibers/nanotubes, and inorganic nanofibers/nanotubes, as well as their researches related, are demonstrated in sequence. Furthermore, the possible mechanism of improving biocompatibility and bioactivity of biomedical materials by nanofibers or nanotubes has been speculated to be that the specific protein absorption on the nanoscaled fibers or tubes plays important roles.

  1. Nanostructured conductive polymeric materials

    Science.gov (United States)

    Al-Saleh, Mohammed H.

    Conductive polymer composites (CPCs) are a suitable alternative to metals in many applications due to their light-weight, corrosion resistance, low cost, ease of processing and design flexibility. CPCs have been formulated using different types of conductive fillers. In this PhD thesis, the focus is on CPCs for electrostatic discharge (ESD) protection and electromagnetic interference (EMI) attenuation. Despite the versatility of conductive fillers, carbon black (CB) has been the dominant filler to make CPCs for ESD protection applications because CB/polymer composites have a cost advantage over all other CPCs. For EMI shielding, stainless steel fibres and metal coated fibers are the preferred fillers, however CPCs made of those fibers are not the dominant EMI shielding materials. Metal coated and polymer plated polymers are the most widely used EMI shielding options. The limited use of CPCs in the EMI shielding market is because the high filler loading required to formulate a composite with an adequate level of shielding remarkably increases the composite price. In order to increase the competitiveness of CPCs, percolation threshold should be minimized as much as possible and composites with high EMI shielding capabilities at low filler loading should be formulated because all conductive fillers are expensive compared to polymers. In this thesis, two different methodologies to reduce percolation threshold in CPCs have been successfully developed and a CPC with exceptional EMI shielding capability has been formulated using copper nanowires as conductive filler. The first percolation threshold reduction technique is based on the selective localization of CB at the interface of immiscible polymer blend. The technique requires adding a copolymer that prefers the blend's interface and for which CB nanoparticles has the highest affinity. The second method is based on producing a CPC powder and then using this powder as a conductive filler to produce composite by dry

  2. Polymeric materials in medication

    CERN Document Server

    Carraher, Charles

    1985-01-01

    The art of using chemical agents for medication dates back into antiquity, although most of the earliest examples used plants, herbs, and other natural materials. The old Egyptian medical papyri, which date from before 1400 B. C. , contain dozens of examples of such medicinal plants and animal extracts. In the Old Testament of the Bible, we can find references to using oil to soften the skin and sores (Isaiah 1:6), the use of tree leaves for medicine (Ezekiel 47:12) and various medical balms (Jeremiah 8:22). Not all these recipes were effective in curing the ailments for which they were used and sometimes the treatment was worse than the disease. Nevertheless, the art of using chemical derived agents for medicines continued to develop and received great impetus during the present century with the rise of synthetic organic chemistry. One of the most vexing problems has always been to achieve specifici­ ty with the medications. While some medical agents do indeed possess a relatively high degree of specificity...

  3. Polymeric Materials for Tissue Engineering of Arterial Substitutes

    OpenAIRE

    Ravi, Swathi; QU, ZHENG; Chaikof, Elliot L.

    2009-01-01

    Cardiovascular disease is the leading cause of mortality in the United States. The limited availability of healthy autologous vessels for bypass grafting procedures has led to the fabrication of prosthetic vascular conduits. Synthetic polymeric materials, while providing the appropriate mechanical strength, lack the compliance and biocompatibility that bioresorbable and naturally occurring protein polymers offer. Vascular tissue engineering approaches have emerged in order to meet the challen...

  4. Marketing NASA Langley Polymeric Materials

    Science.gov (United States)

    Flynn, Diane M.

    1995-01-01

    A marketing tool was created to expand the knowledge of LaRC developed polymeric materials, in order to facilitate the technology transfer process and increase technology commercialization awareness among a non-technical audience. The created brochure features four materials, LaRC-CP, LaRC-RP46, LaRC-SI, and LaRC-IA, and highlights their competitive strengths in potential commercial applications. Excellent opportunities exist in the $40 million per year microelectronics market and the $6 billion adhesives market. It is hoped that the created brochure will generate inquiries regarding the use of the above materials in markets such as these.

  5. Ionic liquid based polymeric liposomes: A stable and biocompatible soft platform for bioelectrochemistry.

    Science.gov (United States)

    Tian, Yanping; Xia, Jiarui; Zhang, Ling; Zhang, Junhui; Jiang, Yi; Zhang, Yao; Yang, Lini; Zhang, Qian; Xia, Lixin

    2016-10-01

    Polymeric liposomes (denoted as ILs-polysomes) are a biocompatible and conductive nanomaterial, which was first utilised as the electrode material for immobilising and biosensing redox enzyme horseradish peroxide (HRP). The morphology and surface property of IL-polysomes was characterised and systematically compared with unpolymerised ionic liquid based liposomes (denoted as ILs-liposomes). Differing from IL-liposomes, IL-polysomes preserves their original morphology and bilayer membrane structure on glassy carbon (GC) electrodes due to the cross-linking of polymerised lipids, thus exhibiting excellent stability and specific biocompability. Because of the existence of imidazolium ionic liquid moieties on the outer surface, IL-polysomes displays a positive charge in aqueous solution, leading to oppositely charged HRP self-assembling onto the vesicles to form HRP/IL-polysomes/PVA/GC electrodes. Owing to the combined merits of ILs and liposomes, electron transfer between HRP-Fe(III)/Fe(II) redox couples of immobilised enzymes and GC electrodes can be achieved. Therefore, HRP/IL-polysomes/PVA/GC electrodes exhibited good electrocatalytic performance toward the electrocatalysis of H2O2. Accordingly, IL-polysomes could act as an efficient charged platform for the self-assembled redox enzymes to realise direct electrochemistry. IL-polysomes have a promising application in the fabrication of third-generation electrochemical biosensors. PMID:27196632

  6. Polymeric materials from renewable resources

    Science.gov (United States)

    Frollini, Elisabete; Rodrigues, Bruno V. M.; da Silva, Cristina G.; Castro, Daniele O.; Ramires, Elaine C.; de Oliveira, Fernando; Santos, Rachel P. O.

    2016-05-01

    The goals of our studies have been the use of renewable raw materials in the preparation of polymeric materials with diversified properties. In this context, lignosulfonate, which is produced in large scale around the world, but not widely used in the production of polymeric materials, was used to replace phenol and polyols in the preparation of phenolic- (Ligno-PH) and polyurethane-type (Ligno-PU) polymers, respectively. These polymers were used to prepare composites reinforced with sisal lignocellulosic fibers. The use of lignosulfonate in the formulation of both types of polymers was beneficial, because in general composites with improved properties, specially impact strength, were obtained. Composites were also prepared from the so called "biopolyethylene" (HDPE), curaua lignocellulosic fiber, and castor oil (CO). All composites HDBPE/CO/Fiber exhibited higher impact strength, when compared to those of the corresponding HDBPE/Fiber. These results, combined with others (eg SEM images of the fractured surfaces) indicated that, in addition to acting as a plasticizer, this oil may have acted as a compatibilizer of the hydrophilic fiber with the hydrophobic polymer. The set of results indicated that (i) mats with nano (diameter ≤ 100nm) and/or ultrafine (submicron scale) fibers were produced, (ii) hybrid fibers were produced (bio-based mats composites), (iii) cellulosic pulp (CP) and/or lignin (Lig) can be combined with PET matrices to control properties such as stiffness and hydrophilicity of the respective mats. Materials with diversified properties were prepared from high content of renewable raw materials, thus fulfilling the proposed targets.

  7. Biocompatibility of Poly (L-Lactic Acid Synthesized In Polymerization Unit By Cytotoxicity And Hemocompatibility Assay And Nanofibers Production

    Directory of Open Access Journals (Sweden)

    Xavier, M.V

    2016-07-01

    Full Text Available The absorbable polyacid is one of the most used and studied materials in tissue engineering. This work synthesized a poly (L-lactic acid (PLLA through ring-opening polymerization and produced nanofibers by the electrospinning process. The PLLA was analyzed by FTIR and the cytotoxicity was evaluated by the MTT assay and Live/Dead®. The hemocompatibility was tested by platelet adhesion and hemolytic activity assay. The tests were performed in contact with human mesenchymal cells at varying times. The high rates of cell viability and proliferation shown by MTT and Live/Dead® tests demonstrate that this PLLA is a non-toxic material and the hemocompatibility assay revealed that the biomaterial was also biocompatible. It was achieved as well the successful production of electrospinning nanofibers, which can be converted for specific biomedical applications in the future

  8. Fabrication of Biocompatible, Vibrational Magnetoelastic Materials for Controlling Cellular Adhesion

    OpenAIRE

    Rajachar, Rupak M.; Keat Ghee Ong; Ee Lim Tan; Hal R. Holmes

    2012-01-01

    This paper describes the functionalization of magnetoelastic (ME) materials with Parylene-C coating to improve the surface reactivity to cellular response. Previous study has demonstrated that vibrating ME materials were capable of modulating cellular adhesion when activated by an externally applied AC magnetic field. However, since ME materials are not inherently biocompatible, surface modifications are needed for their implementation in biological settings. Here, the long-term stability of ...

  9. Size-engineered biocompatible polymeric nanophotosensitizer for locoregional photodynamic therapy of cancer.

    Science.gov (United States)

    Jeong, Keunsoo; Park, Solji; Lee, Yong-Deok; Kang, Chi Soo; Kim, Hyun Jun; Park, Hyeonjong; Kwon, Ick Chan; Kim, Jungahn; Park, Chong Rae; Kim, Sehoon

    2016-08-01

    Current approaches in use of water-insoluble photosensitizers for photodynamic therapy (PDT) of cancer often demand a nano-delivery system. Here, we report a photosensitizer-loaded biocompatible nano-delivery formulation (PPaN-20) whose size was engineered to ca. 20nm to offer improved cell/tissue penetration and efficient generation of cytotoxic singlet oxygen. PPaN-20 was fabricated through the physical assembly of all biocompatible constituents: pyropheophorbide-a (PPa, water-insoluble photosensitizer), polycaprolactone (PCL, hydrophobic/biodegradable polymer), and Pluronic F-68 (clinically approved polymeric surfactant). Repeated microemulsification/evaporation method resulted in a fine colloidal dispersion of PPaN-20 in water, where the particulate PCL matrix containing well-dispersed PPa molecules inside was stabilized by the Pluronic corona. Compared to a control sample of large-sized nanoparticles (PPaN-200) prepared by a conventional solvent displacement method, PPaN-20 revealed optimal singlet oxygen generation and efficient cellular uptake by virtue of the suitably engineered size and constitution, leading to high in vitro phototoxicity against cancer cells. Upon administration to tumor-bearing mice by peritumoral route, PPaN-20 showed efficient tumor accumulation by the enhanced cell/tissue penetration evidenced by in vivo near-infrared fluorescence imaging. The in vivo PDT treatment with peritumorally administrated PPaN-20 showed significantly enhanced suppression of tumor growth compared to the control group, demonstrating great potential as a biocompatible photosensitizing agent for locoregional PDT treatment of cancer. PMID:27107384

  10. Biocompatibility of root-end filling materials: recent update.

    Science.gov (United States)

    Saxena, Payal; Gupta, Saurabh Kumar; Newaskar, Vilas

    2013-08-01

    The purpose of a root-end filling is to establish a seal between the root canal space and the periradicular tissues. As root-end filling materials come into contact with periradicular tissues, knowledge of the tissue response is crucial. Almost every available dental restorative material has been suggested as the root-end material of choice at a certain point in the past. This literature review on root-end filling materials will evaluate and comparatively analyse the biocompatibility and tissue response to these products, with primary focus on newly introduced materials. PMID:24010077

  11. Deformation and flow of polymeric materials

    CERN Document Server

    Münstedt, Helmut

    2014-01-01

    This book describes the properties of single polymer molecules and polymeric materials and the methods how to characterize them. Molar masses, molar mass distributions and branching structure are discussed in detail. These properties are decisive for a deeper understanding of structure/properties relationships of polymeric materials. This book therefore describes and discusses them in detail. The mechanical behavior as a function of time and temperature is a key subject of the book. The authors present it on the basis of many original results they have obtained in their long research careers. They present the temperature dependence of mechanical properties of various polymeric materials in a wide temperature range: from cryogenic temperatures to the melt. Besides an extensive data collection on the transitions of various different polymeric materials, they also carefully present the physical explanations of the observed phenomena. Glass transition and melting temperatures are discussed, particularly, with the...

  12. Biodegradation and biocompatibility of mechanically active magnetoelastic materials

    International Nuclear Information System (INIS)

    Magnetoelastic (ME) materials have many advantages for use as sensors and actuators due to their wireless, passive nature. This paper describes the application of ME materials as biodegradable implants with controllable degradation rates. Experiments have been conducted to show that degradation rates of ME materials are dependent on the material compositions. In addition, it was shown that the degradation rates of the ME materials can be controlled remotely by applying a magnetic field, which causes the ME materials to generate low-magnitude vibrations that hasten their degradation rates. Another concern of ME materials for medical applications is biocompatibility. Indirect cytotoxicity analyses were performed on two types of ME materials: Metglas™ 2826 MB (FeNiMoB) and iron–gallium alloy. While results indicate Metglas is not biocompatible, the degradation products of iron–gallium materials have shown no adverse effects on cell viability. Overall, these results present the possibility of using ME materials as biodegradable, magnetically-controlled active implants. (paper)

  13. Charge trapping and detrapping in polymeric materials

    OpenAIRE

    Chen, George; Xu, Zhiqiang

    2009-01-01

    Space charge formation in polymeric materials can cause some serious concern for design engineers as the electric field may severely be distorted, leading to part of the material being overstressed. At the worst, this may result in material degradation and possibly premature failure. It is therefore important to understand charge generation, trapping, and detrapping processes in the material. In the present paper, the characteristics of charge trapping and detrapping in low density polyethyle...

  14. Polymeric materials obtained by electron beam irradiation

    International Nuclear Information System (INIS)

    Research activities in the field of electron beam irradiation of monomer aqueous solution to produce polymeric materials used for waste waters treatment, agriculture and medicine are presented. The technologies and special features of these polymeric materials are also described. The influence of the chemical composition of the solution to ba irradiated, absorbed dose level and absorbed dose rate level are discussed. Two kinds of polyelectrolytes, PA and PV types and three kinds of hydrogels, pAAm, pAAmNa and pNaAc types, the production of which was first developed with IETI-10000 Co-60 source and then adapted to the linacs built in Accelerator Laboratory, are described. (author)

  15. Polymeric matrix materials for infrared metamaterials

    Science.gov (United States)

    Dirk, Shawn M; Rasberry, Roger D; Rahimian, Kamyar

    2014-04-22

    A polymeric matrix material exhibits low loss at optical frequencies and facilitates the fabrication of all-dielectric metamaterials. The low-loss polymeric matrix material can be synthesized by providing an unsaturated polymer, comprising double or triple bonds; partially hydrogenating the unsaturated polymer; depositing a film of the partially hydrogenated polymer and a crosslinker on a substrate; and photopatterning the film by exposing the film to ultraviolet light through a patterning mask, thereby cross-linking at least some of the remaining unsaturated groups of the partially hydrogenated polymer in the exposed portions.

  16. Cytotoxicity and biocompatibility of direct and indirect pulp capping materials

    Directory of Open Access Journals (Sweden)

    Karin Cristina da Silva Modena

    2009-12-01

    Full Text Available There are several studies about the cytotoxic effects of dental materials in contact with the pulp tissue, such as calcium hydroxide (CH, adhesive systems, resin composite and glass ionomer cements. The aim of this review article was to summarize and discuss the cytotoxicity and biocompatibility of materials used for protection of the dentin-pulp complex, some components of resin composites and adhesive systems when placed in direct or indirect contact with the pulp tissue. A large number of dental materials present cytotoxic effects when applied close or directly to the pulp, and the only material that seems to stimulate early pulp repair and dentin hard tissue barrier formation is CH.

  17. Polymeric Materials - introduction and degradation

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios

    1999-01-01

    These notes support the polymer part of the courses 91742 and 91762 (Materials and Corrosion/degradation of materials) taught in IFAKthey contain a short introduction on group contribution methods for estimating properties of polymers, polymer thermodynamics, viscoelasticity models as well as a...

  18. Pharmaceutical Applications of Polymeric Nano materials

    International Nuclear Information System (INIS)

    With significant attention focused on nano science and nano technology in recent years, nano materials have been used in a wide variety of applications such as automotive, environmental, energy, catalysis, biomedical, drug delivery, and polymeric industries. Among those fields, the application of nano materials with pharmaceutical science is an emerging and rapidly growing field and has drawn increasing attention recently. Research and development in this field is mainly focused on several aspects such as the discoveries of novel functional nano materials, exploration on nanoparticles with controlled and targeted drug delivery characteristics, and investigation of bio functionalized and diagnostic nano materials. In this special issue, we have invited a few papers related to recent advances in pharmaceutical application of polymeric nano materials

  19. Fingerprinting the thermal history of polymeric materials

    International Nuclear Information System (INIS)

    Knowledge of temperatures experienced by a polymeric material in storage or in the field helps predict the useful life or remaining service life of the parent component. This report describes a nondestructive test procedure to characterize the maximum temperature and time-at-temperature of semicrystalline polymers commonly used in electrical cable insulations and as parts of other components

  20. Chemical Compatibility of Polymeric Materials.

    Science.gov (United States)

    Solen, Kenneth A.; Kuchar, Marvin C.

    1990-01-01

    Presents some principles for specifying general classes of polymers for predicting relative chemical attack from acids, bases, oxidants, and certain common antagonists. Also discusses predicting relative solvent effects. Suggests uses of this information in two or three lectures in a chemical engineering materials course. (YP)

  1. Polymeric materials for atomic power industry

    International Nuclear Information System (INIS)

    In the atomic power industry such as nuclear power generating stations, organic polymeric materials are widely used. Those materials have superior properties for electric insulation, for the fabricability and flexibility, so they are conveniently used from the viewpoint of economics too. Here, it is important to recognize the limit of their usage. The first chapter deals with the introduction of the polymeric materials for atomic power industry, i.e. their limiting usage under irradiation, and type test of the equipments. The second chapter describes the testing of the flamability of wire and cable which is mostly concerned at present. The third chapter introduces the accident at the Three Mile Island Nuclear Power Generating Station, which accident has given strong shock in the world, and the last chapter tells the fire accident at the Browns Ferry Nuclear Power Generating Station, which accident has accelerated the development of the fire resistant polymers. (author)

  2. Fabrication of Biocompatible, Vibrational Magnetoelastic Materials for Controlling Cellular Adhesion

    Directory of Open Access Journals (Sweden)

    Rupak M. Rajachar

    2012-02-01

    Full Text Available This paper describes the functionalization of magnetoelastic (ME materials with Parylene-C coating to improve the surface reactivity to cellular response. Previous study has demonstrated that vibrating ME materials were capable of modulating cellular adhesion when activated by an externally applied AC magnetic field. However, since ME materials are not inherently biocompatible, surface modifications are needed for their implementation in biological settings. Here, the long-term stability of the ME material in an aqueous and biological environment is achieved by chemical-vapor deposition of a conformal Parylene-C layer, and further functionalized by methods of oxygen plasma etching and protein adsorption. In vitro cytotoxicity measurement and characterization of the vibrational behavior of the ME materials showed that Parylene-C coatings of 10 µm or greater could prevent hydrolytic degradation without sacrificing the vibrational behavior of the ME material. This work allows for long-term durability and functionality of ME materials in an aqueous and biological environment and makes the potential use of this technology in monitoring and modulating cellular behavior at the surface of implantable devices feasible.

  3. Whole genome expression profiling using DNA microarray for determining biocompatibility of polymeric surfaces

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Wang, Zhenyu; Kutter, Jörg Peter;

    2006-01-01

    There is an ever increasing need to find surfaces that are biocompatible for applications like medical implants and microfluidics-based cell culture systems. The biocompatibility of five different surfaces with different hydrophobicity was determined using gene expression profiling as well as more...

  4. Whole genome expression profiling using DNA microarray for determining biocompatibility of polymeric surfaces

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Wang, Zhenyu; Kutter, Jörg Peter; Dufva, Hans Martin; Wolff, Anders

    2006-01-01

    There is an ever increasing need to find surfaces that are biocompatible for applications like medical implants and microfluidics-based cell culture systems. The biocompatibility of five different surfaces with different hydrophobicity was determined using gene expression profiling as well as more...... conventional methods to determine biocompatibility such as cellular growth rate, morphology and the hydrophobicity of the surfaces. HeLa cells grown on polymethylmethacrylate (PMMA) or a SU-8 surface treated with HNO3-ceric ammonium nitrate (HNO3-CAN) and ethanolamine showed no differences in growth rate......, morphology or gene expression profiles as compared to HeLa cells grown in cell culture flasks. Cells grown on SU-8 treated with only HNO3-CAN showed almost the same growth rate (36 ¡ 1 h) and similar morphology as cells grown in cell culture flasks (32 ¡ 1 h), indicating good biocompatibility. However, more...

  5. Radiation electric ocnductivity of polymeric materials

    International Nuclear Information System (INIS)

    Investigated was the radiation electric conductivity of some polymeric materials (polyethylene terephthalate, polystyrene, polyimeide, fluorolon F-4) under the effect of gamma radiation. Experiments were carried out at room temperature in vacuum on 11-60 μm thick films of two types, differing in the method of silver electrode spraying. It is shown that at radiation dose rate of 100 R/s electric conductivity of films at cathodic electrode spraying is greater than their electric conductivity at the thermal spraying method. A long aging of investigated materials in strong electric fields may change essentially the value of radiation electric conductivity and the character of its dependence on radiation dose rate

  6. Rapid Biocompatibility Analysis of Materials via In Vivo Fluorescence Imaging of Mouse Models

    OpenAIRE

    Bratlie, Kaitlin M.; Dang, Tram T.; Lyle, Stephen; Nahrendorf, Matthias; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G.

    2010-01-01

    Background: Many materials are unsuitable for medical use because of poor biocompatibility. Recently, advances in the high throughput synthesis of biomaterials has significantly increased the number of potential biomaterials, however current biocompatibility analysis methods are slow and require histological analysis. Methodology/Principal Findings: Here we develop rapid, non-invasive methods for in vivo quantification of the inflammatory response to implanted biomaterials. Material...

  7. Polymeric materials for solar thermal applications

    CERN Document Server

    Köhl, Michael; Papillon, Philippe; Wallner, Gernot M; Saile, Sandrin

    2012-01-01

    Bridging the gap between basic science and technological applications, this is the first book devoted to polymers for solar thermal applications.Clearly divided into three major parts, the contributions are written by experts on solar thermal applications and polymer scientists alike. The first part explains the fundamentals of solar thermal energy especially for representatives of the plastics industry and researchers. Part two then goes on to provide introductory information on polymeric materials and processing for solar thermal experts. The third part combines both of these fields, dis

  8. Novel hybrid polymeric materials for barrier coatings

    Science.gov (United States)

    Pavlacky, Erin Christine

    Polymer-clay nanocomposites, described as the inclusion of nanometer-sized layered silicates into polymeric materials, have been widely researched due to significant enhancements in material properties with the incorporation of small levels of filler (1--5 wt.%) compared to conventional micro- and macro-composites (20--30 wt.%). One of the most promising applications for polymer-clay nanocomposites is in the field of barrier coatings. The development of UV-curable polymer-clay nanocomposite barrier coatings was explored by employing a novel in situ preparation technique. Unsaturated polyesters were synthesized in the presence of organomodified clays by in situ intercalative polymerization to create highly dispersed clays in a precursor resin. The resulting clay-containing polyesters were crosslinked via UV-irradiation using donor-acceptor chemistry to create polymer-clay nanocomposites which exhibited significantly enhanced barrier properties compared to alternative clay dispersion techniques. The impact of the quaternary alkylammonium organic modifiers, used to increase compatibility between the inorganic clay and organic polymer, was studied to explore influence of the organic modifier structure on the nanocomposite material properties. By incorporating just the organic modifiers, no layered silicates, into the polyester resins, reductions in film mechanical and thermal properties were observed, a strong indicator of film plasticization. An alternative in situ preparation method was explored to further increase the dispersion of organomodified clay within the precursor polyester resins. In stark contrast to traditional in situ polymerization methods, a novel "reverse" in situ preparation method was developed, where unmodified montmorillonite clay was added during polyesterification to a reaction mixture containing the alkylammonium organic modifier. The resulting nanocomposite films exhibited reduced water vapor permeability and increased mechanical properties

  9. Degradable polymeric materials for osteosynthesis: Tutorial

    Directory of Open Access Journals (Sweden)

    D Eglin

    2008-12-01

    Full Text Available This report summarizes the state of the art and recent developments and advances in the use of degradable polymers devices for osteosynthesis. The current generation of biodegradable polymeric implants for bone repair utilising designs copied from metal implants, originates from the concept that devices should be supportive and as “inert” substitute to bone tissue. Today degradable polymeric devices for osteosynthesis are successful in low or mild load bearing applications. However, the lack of carefully controlled randomized prospective trials that document their efficacy in treating a particular fracture pattern is still an issue. Then, the choice between degradable and non-degradable devices must be carefully weighed and depends on many factors such as the patient age and condition, the type of fracture, the risk of infection, etc. The improvement of the biodegradable devices mechanical properties and their degradation behaviour will have to be achieved to broaden their use. The next generation of biodegradable implants will probably see the implementation of the recent gained knowledge in cell-material interactions and cells therapy, with a better control of the spatial and temporal interfaces between the material and the surrounding bone tissue.

  10. Biocompatibility of plasma polymerized sandblasted large grit and acid titanium surface

    International Nuclear Information System (INIS)

    Sandblasted large grit and acid treatment (SLA) is the most common approach to alter the surface topography and increase the surface area of an implant. In this study, plasma polymerized SLA-treated titanium (Ti) surfaces were prepared by the deposition of a polymeric thin film containing COOH, NH2 and OH groups through the plasma polymerization of acrylic acid, allyl amine and allyl alcohol, respectively. The Ti surfaces were characterized by field emission scanning electron microscopy, attenuated total reflectance-Fourier transform infrared and contact angle measurements. The proliferation and differentiation of MC3T3-E1 cell cultured on the Ti, SLA and plasma polymerized SLA/Ti surfaces were examined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and alkaline phosphatase assay. The cell proliferation study revealed significantly enhanced cell viability on the COOH/SLA and NH2/SLA surfaces compared to the other surfaces.

  11. Biocompatibility of plasma polymerized sandblasted large grit and acid titanium surface

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, Suncheon, 540-742 (Korea, Republic of); Lee, Kang [Department of Dental Materials, School of Dentistry, Chosun University, 375 Seosuk dong, Dong gu, Gwangju 501-759 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, Chosun University, 375 Seosuk dong, Dong gu, Gwangju 501-759 (Korea, Republic of)

    2012-10-30

    Sandblasted large grit and acid treatment (SLA) is the most common approach to alter the surface topography and increase the surface area of an implant. In this study, plasma polymerized SLA-treated titanium (Ti) surfaces were prepared by the deposition of a polymeric thin film containing COOH, NH{sub 2} and OH groups through the plasma polymerization of acrylic acid, allyl amine and allyl alcohol, respectively. The Ti surfaces were characterized by field emission scanning electron microscopy, attenuated total reflectance-Fourier transform infrared and contact angle measurements. The proliferation and differentiation of MC3T3-E1 cell cultured on the Ti, SLA and plasma polymerized SLA/Ti surfaces were examined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and alkaline phosphatase assay. The cell proliferation study revealed significantly enhanced cell viability on the COOH/SLA and NH{sub 2}/SLA surfaces compared to the other surfaces.

  12. Study of biocompatible properties of polymeric scaffolds derived from vegetable oils for application in tissue engineering

    International Nuclear Information System (INIS)

    Tissue engineering and regenerative medicine have as main objective the morphologic/functional reestablishment of injured tissues and organs using cells, scaffolds, stem cells and control of immunological/biochemical responses promoted by the body. In addition, materials science seeks to develop biocompatible biomaterials that do not promote unwanted immune responses and provide the re-establishment of the functions of the tissue/organ. Polymers of natural origin stand out as biomaterials to resemble biological macromolecules, similarity to the extracellular matrix, reduced chance of inflammation and chronic pacing low or no toxicity. This study aimed the development of macromolecular arrays originated from epoxidized soybean oil (OSE), analyzing the relationship between the chemical structure/biological activity of the macromolecular arrays for use as biomaterials in tissue engineering. The synthesis of OSE was performed through the oil chemical route, whose efficiency was determined by infrared spectroscopy and the reaction yield of 85%, determined by nuclear magnetic resonance spectroscopy. From the analysis by differential scanning calorimetry, it was detected a decrease of the glass transition temperature of the epoxidized soybean oil polymer (POSE) compared with OSE, suggesting an increase of the growth of polymer chains of POSE. Thermogravimetric analysis was performed to define the OSE degradation profile, which degrades in two steps. The POSE degrades in just one step and shows higher thermal stability by the increased molecular interactions. The hydrophilicity and crosslinking of POSE was promoted by the addition of 2-hydroxyethyl methacrylate (HEMA) with the monomer grafting by gamma irradiation. The results showed an increased mechanical stability, gelation and water absorption with the HEMA content increasing. Finally, the degree of crystallinity for such polymers grafted with HEMA was 27.5%, estimated by X-ray diffractometry. The second stage was

  13. Thermo-Responsive and Biocompatible Diblock Copolymers Prepared via Reversible Addition-Fragmentation Chain Transfer (RAFT Radical Polymerization

    Directory of Open Access Journals (Sweden)

    Kenichi Fukuda

    2014-03-01

    Full Text Available Poly(2-(methacryloyloxyethyl phosphorylcholine-b-poly(N,N-diethyl acrylamide (PMPCm-PDEAn was synthesized via reversible addition-fragmentation chain transfer (RAFT controlled radical polymerization. Below, the critical aggregation temperature (CAT the diblock copolymer dissolved in water as a unimer with a hydrodynamic radius (Rh of ca. 5 nm. Above the CAT the diblock copolymers formed polymer micelles composed of a PDEA core and biocompatible PMPC shells, due to hydrophobic self-aggregation of the thermo-responsive PDEA block. A fluorescence probe study showed that small hydrophobic small guest molecules could be incorporated into the core of the polymer micelle above the CAT. The incorporated guest molecules were released from the core into the bulk aqueous phase when the temperature decreased to values below the CAT because of micelle dissociation.

  14. Formation of microporous polymeric materials by microemulsion radiation polymerization of butyl acrylate

    International Nuclear Information System (INIS)

    A microemulsion system composed of butyl acrylate (BA) and water with the mixture of sodium 12-acryloxy-9-octadecenate (SAO) and octylphenoxypoly(ethoxyethanol) (OP-10) as emulsifier was initiated by γ-ray at room temperature to polymerize and produce microporous polymeric materials. The morphology and swelling characteristics of the resulting polymeric materials were studied. It was found that they depend strongly on the composition (water content, crosslinker content, emulsifier content) of the precursor microemulsions. In addition, the swelling properties of polymer so prepared were also found to be sensitive to the pH of the swelling medium. The change in swelling behaviors of the polymeric materials is discussed in terms of the polyelectrolyte effect exhibited by polymerized anionic emulsifier SAO. (author)

  15. Biocompatible high performance hyperbranched epoxy/clay nanocomposite as an implantable material

    International Nuclear Information System (INIS)

    Polymeric biomaterials are in extensive use in the domain of tissue engineering and regenerative medicine. High performance hyperbranched epoxy is projected here as a potential biomaterial for tissue regeneration. Thermosetting hyperbranched epoxy nanocomposites were prepared with Homalomena aromatica rhizome oil-modified bentonite as well as organically modified montmorillonite clay. Fourier transformed infrared spectroscopy, x-ray diffraction and scanning and transmission electron microscopic techniques confirmed the strong interfacial interaction of clay layers with the epoxy matrix. The poly(amido amine)-cured thermosetting nanocomposites exhibited high mechanical properties like impact resistance (>100 cm), scratch hardness (>10 kg), tensile strength (48–58 MPa) and elongation at break (11.9–16.6%). Cytocompatibility of the thermosets was found to be excellent as evident by MTT and red blood cell hemolytic assays. The nanocomposites exhibited antimicrobial activity against Staphylococcus aureus (ATCC 11632), Escherichia coli (ATCC 10536), Mycobacterium smegmatis (ATCC14468) and Candida albicans (ATCC 10231) strains. In vivo biocompatibility of the best performing nanocomposite was ascertained by histopathological study of the brain, heart, liver and skin after subcutaneous implantation in Wistar rats. The material supported the proliferation of dermatocytes without induction of any sign of toxicity to the above organs. The adherence and proliferation of cells endorse the nanocomposite as a non-toxic biomaterial for tissue regeneration. (paper)

  16. Effect of microwave power on EPR spectra of natural and synthetic dental biocompatible materials

    Directory of Open Access Journals (Sweden)

    Adamczyk Jakub

    2015-07-01

    Full Text Available Paramagnetic centers in the two exemplary synthetic and natural dental biocompatible materials applied in implantology were examined by the use of an X-band (9.3 GHz electron paramagnetic resonance (EPR spectroscopy. The EPR spectra were measured in the range of microwave power 2.2–70 mW. The aims of this work were to compare paramagnetic centers concentrations in different dental biocompatible materials and to determine the effect of microwave power on parameters of their EPR spectra. It is the very first and innovatory examination of paramagnetic centers in these materials. It was pointed out that paramagnetic centers existed in both natural (~1018 spin/g and synthetic (~1019 spin/g dental biocompatible materials, but the lower free radical concentration characterized the natural sample. Continuous microwave saturation of EPR spectra indicated that faster spin-lattice relaxation processes existed in synthetic dental biocompatible materials than in natural material. Linewidths (ΔBpp of the EPR spectra of the natural dental material slightly increased for the higher microwave powers. Such effect was not observed for the synthetic material. The broad EPR lines (ΔBpp: 2.4 mT, 3.9 mT, were measured for the natural and synthetic dental materials, respectively. Probably strong dipolar interactions between paramagnetic centers in the studied samples may be responsible for their line broadening. EPR spectroscopy is the useful experimental method in the examination of paramagnetic centers in dental biocompatible materials.

  17. Biocompatibility of coronary stent materials: effect of electrochemical polishing

    Energy Technology Data Exchange (ETDEWEB)

    Scheerder, I. de [University Hospital Leuven (Belgium). Dept. of Cardiology; Sohier, J.; Froyen, L.; Humbeeck, J. van [Louvain Univ. (Belgium). Dept. of Metallurgy and Materials Engineering; Verbeken, E. [University Hospital Leuven (Belgium). Dept. of Pathology

    2001-02-01

    Percutaneous Transluminal Coronary Revascularization (PTCR) is now a widely accepted treatment modality for atherosclerotic coronary artery disease. Current multicenter randomized trials comparing PTCR with the more invasive Coronary Artery Bypass Grafting could not show long-term significant survival differences. During the last two decades progress has been made to further optimize PTCR. The most logic approach to treat atherosclerotic coronary narrowings is to remove the atherosclerotic material using especially developed devices. Several trials, however, could not show a significant beneficial outcome after use of these devices compared to plain old balloon angioplasty. Another approach was to implant a coronary prothesis (stent), scaffolding the diseased coronary artery after PTCA. This approach resulted in a decreased restenosis rate at follow-up. The beneficial effects of stenting, however, was not found to be related to the inhibition of the neointimal cellular proliferation after vascular injury, but simply to be the mechanical result of overstretching of the treated vessel segment. The most important remaining clinical problem after stenting remains the neointimal hyperplasia within the stent, resulting in a significant stent narrowing in 13 to 30% of patients. Further efforts to improve the clinical results of coronary stenting should focus on the reduction of this neointimal hyperplasia. Neointimal hyperplasia after stent implantation results from (1) a healting response to the injury caused by the stent implantation and (2) a foreign body response to the stent itself. Factors that seem to influence the neointimal hyperplastic response are genetic, local disease related, stent delivery related and stent related factors. Biocompatibilisation of coronary stents by looking for more biocompatible metal alloys, optimized surface characteristics and optimized stent designs should result in a better late patency. Furthermore drug eluting and radioactive stents

  18. Survey and research on precision polymerization polymeric materials; Seimitsu jugo kobunshi zairyo ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Survey and research on the precision control of primary structure of polymeric materials and the precision evaluation technology have been conducted to develop advanced polymeric materials. It is proposed that the three basic processes of polymer synthesis, i.e., addition, condensation, and biomimesis, in forming the precision polymerization skeleton are to be covered through a centralized joint research effort with participation of industry, academia, and the government institute and under the leadership of researchers from academic institutions as the team leaders. For the study of technology trends, international conferences held in UK, Germany, and Hawaii are introduced, and domestic meetings, i.e., Annual Polymer Congress and Polymer Conference, are summarized. In addition, Precision Polymerization Forum and International Workshop on Precision Polymerization were held. The basic studies include a quantum-chemical elucidation of the elementary process in polymerization reaction, time-resolved analysis of polymerization process and polymer properties, synthesis of polymers with controlled microstructures by coordination polymerization using metal complexes, synthesis of polymer with controlled microstructures by precision polycondensation, molecular recognition in catalyst-reaction site, and synthesis of imprinting polymers. 246 refs., 117 figs., 14 tabs.

  19. Polymerization Simulator for Introductory Polymer and Material Science Courses

    Science.gov (United States)

    Chirdon, William M.

    2010-01-01

    This work describes how molecular simulation of polymerization reactions can be used to enrich introductory polymer or material science courses to give students a deeper understanding of free-radical chain and stepwise growth polymerization reactions. These simulations have proven to be effective media for instruction that do not require material…

  20. Light induced polymerization of resin composite restorative materials

    Directory of Open Access Journals (Sweden)

    Blažić Larisa

    2004-01-01

    Full Text Available Introduction Dimensional stability of polymer-based dental materials is compromised by polymerization reaction of the monomer. The conversion into a polymer is accompanied by a closer packing of molecules, which leads to volume reduction called curing contraction or polymerization shrinkage. Curing contraction may break the adhesion between the adhesive system and hard tooth tissues forming micrographs which may result in marginal deterioration, recurrent caries and pulp injury. Polymerization shrinkage of resin-based restorative dental materials Polymerization of the organic phase (monomer molecules of resin-based dental materials causes shrinkage. The space occupied by filler particles is not associated with polymerization shrinkage. However, high filler loading within certain limits, can contribute to a lesser curing contraction. Polymerization shrinkage stress and stress reduction possibilities Polymerization shrinkage stress of polymer-based dental resins can be controlled in various ways. The adhesive bond in tooth-restoration interface guides the contraction forces to cavity walls. If leakage occurs, complications like secondary caries and pulpal irritation may jeopardize the longevity of a restoration. Stress relieve can be obtained by modifications of the monomer and photoinitiator, or by specially designed tooth preparation and application of bases and liners of low modulus of elasticity. The polymerization contraction can be compensated by water absorption due to oral cavity surrounding. The newest approach to stress relief is based on modulation of polymerization initiation. Conclusion This work deals with polymerization contraction and how to achieve leak-proof restoration. Restorative techniques that may reduce the negative effect of polymerization shrinkage stress need further research in order to confirm up-to-date findings.

  1. Novel biocompatible materials for in vivo two-photon polymerisation

    International Nuclear Information System (INIS)

    Two-photon polymerisation (2PP) is a versatile laser fabrication technique that allows the creation of 3D structures at micro- and nanometre precision. The structures are created additively in direct accordance to a computer-aided design (CAD). It requires tightly focused fs-pulsed light sources usually operating in the near infrared wavelength range. In this region, biological tissues exhibit a window of transparency and only absorb light minimally. When operating below a certain pulse energy threshold, the laser light does not cause any cellular damage. This theoretically allows inducing 2PP in the presence of living biological tissues and cells. Suitable biocompatible formulations that can render bioactive constructs would potentially allow building a dynamic environment with topographical, chemical and mechanical cues similar to that of the natural extracellular matrix. In that way, 2PP would allow to alter key elements of this environment without changing any other influencing factors. To explore these possibilities, 2PP has to overcome two main limitations, the slow process speeds and the lack of available optimised formulations. In this thesis, we report the design and realisation of a 2PP experimental setup, which allows fabricating hydrogel structures from novel water-based formulations. Writing speeds of above 100 mm/s are feasible, which is the highest speed reported in 2PP. Moreover, the presented components have the potential to be formed in vivo, in the presence of living cells and tissues. Using water-soluble two-photon optimised photoinitiators, we could effectively cross-link acrylates in formulations of up to 80% water content. As acrylates show a tendency towards Michael addition to proteins, we explored the use of vinyl ester and vinyl carbonate monomers for 2PP. In contrast to acrylic polymers, which form potentially toxic poly (acrylic acid), vinyl ester and carbonate polymers form biocompatible poly (vinyl alcohol) during degradation

  2. The Effect of Polymeric Nanoparticles on Biocompatibility of Carrier Red Blood Cells.

    Directory of Open Access Journals (Sweden)

    Daniel Pan

    Full Text Available Red blood cells (RBCs can be used for vascular delivery of encapsulated or surface-bound drugs and carriers. Coupling to RBC prolongs circulation of nanoparticles (NP, 200 nm spheres, a conventional model of polymeric drug delivery carrier enabling their transfer to the pulmonary vasculature without provoking overt RBC elimination. However, little is known about more subtle and potentially harmful effects of drugs and drug carriers on RBCs. Here we devised high-throughput in vitro assays to determine the sensitivity of loaded RBCs to osmotic stress and other damaging insults that they may encounter in vivo (e.g. mechanical, oxidative and complement insults. Sensitivity of these tests is inversely proportional to RBC concentration in suspension and our results suggest that mouse RBCs are more sensitive to damaging factors than human RBCs. Loading RBCs by NP at 1:50 ratio did not affect RBCs, while 10-50 fold higher NP load accentuated RBC damage by mechanical, osmotic and oxidative stress. This extensive loading of RBC by NP also leads to RBCs agglutination in buffer; however, addition of albumin diminished this effect. These results provide a template for analyses of the effects of diverse cargoes loaded on carrier RBCs and indicate that: i RBCs can tolerate carriage of NP at doses providing loading of millions of nanoparticles per microliter of blood; ii tests using protein-free buffers and mouse RBCs may overestimate adversity that may be encountered in humans.

  3. Applications of polymeric smart materials to environmental problems.

    OpenAIRE

    Gray, H N; Bergbreiter, D E

    1997-01-01

    New methods for the reduction and remediation of hazardous wastes like carcinogenic organic solvents, toxic materials, and nuclear contamination are vital to environmental health. Procedures for effective waste reduction, detection, and removal are important components of any such methods. Toward this end, polymeric smart materials are finding useful applications. Polymer-bound smart catalysts are useful in waste minimization, catalyst recovery, and catalyst reuse. Polymeric smart coatings ha...

  4. Biocompatible polymeric micelles with polysorbate 80 for use in brain targeting

    Science.gov (United States)

    Craparo, E. F.; Ognibene, M. C.; Casaletto, M. P.; Pitarresi, G.; Teresi, G.; Giammona, G.

    2008-12-01

    In this paper, the synthesis and characterization of novel amphiphilic graft copolymers based on an α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) backbone and D,L-polylactic acid (PLA) hydrophobic side chains are reported. These copolymers were obtained starting from PHEA-ethylenediamine (PHEA-EDA), which was functionalized with polysorbate 80 (PS80) and/or PLA in order to obtain the PHEA-EDA-PS80-PLA and PHEA-EDA-PLA samples, respectively. The degrees of derivatization, DDPS80 and DDPLA, of PHEA-EDA-PS80-PLA, calculated by 1H-NMR, resulted in being 1.2 ± 0.03 mol% and 0.54 ± 0.05 mol%, respectively, while that of PHEA-EDA-PLA was found to be 0.60 ± 0.05 mol%. Size exclusion chromatography (SEC) analysis confirmed the occurrence of derivatization, the molecular weight values being close to the theoretical ones. Polymeric micelles from PHEA-EDA-PLA and PHEA-EDA-PS80-PLA copolymers were obtained by using the dialysis method and were characterized in terms of mean size, zeta potential, critical aggregation concentration (CAC), and surface composition by x-ray photoelectron spectroscopy (XPS) analysis, which demonstrated the presence of PS80 onto the PHEA-EDA-PS80-PLA micelle surface. In vitro experiments demonstrated that these systems had no cytotoxic effects on 16 HBE, Caco2, HuDe and K562 cell lines, and no haemolytic activity. Moreover, both PHEA-EDA-PS80-PLA and PHEA-EDA-PLA micelles were able to penetrate into Neuro2a cells and, in the case of PS80 decorated micelles, to escape from phagocytosis by the J774 A1 macrophages.

  5. Biocompatible polymeric micelles with polysorbate 80 for use in brain targeting

    International Nuclear Information System (INIS)

    In this paper, the synthesis and characterization of novel amphiphilic graft copolymers based on an α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) backbone and D,L-polylactic acid (PLA) hydrophobic side chains are reported. These copolymers were obtained starting from PHEA-ethylenediamine (PHEA-EDA), which was functionalized with polysorbate 80 (PS80) and/or PLA in order to obtain the PHEA-EDA-PS80-PLA and PHEA-EDA-PLA samples, respectively. The degrees of derivatization, DDPS80 and DDPLA, of PHEA-EDA-PS80-PLA, calculated by 1H-NMR, resulted in being 1.2 ± 0.03 mol% and 0.54 ± 0.05 mol%, respectively, while that of PHEA-EDA-PLA was found to be 0.60 ± 0.05 mol%. Size exclusion chromatography (SEC) analysis confirmed the occurrence of derivatization, the molecular weight values being close to the theoretical ones. Polymeric micelles from PHEA-EDA-PLA and PHEA-EDA-PS80-PLA copolymers were obtained by using the dialysis method and were characterized in terms of mean size, zeta potential, critical aggregation concentration (CAC), and surface composition by x-ray photoelectron spectroscopy (XPS) analysis, which demonstrated the presence of PS80 onto the PHEA-EDA-PS80-PLA micelle surface. In vitro experiments demonstrated that these systems had no cytotoxic effects on 16 HBE, Caco2, HuDe and K562 cell lines, and no haemolytic activity. Moreover, both PHEA-EDA-PS80-PLA and PHEA-EDA-PLA micelles were able to penetrate into Neuro2a cells and, in the case of PS80 decorated micelles, to escape from phagocytosis by the J774 A1 macrophages.

  6. Effect of microwave power on EPR spectra of natural and synthetic dental biocompatible materials

    OpenAIRE

    Adamczyk Jakub; Ramos Paweł; Pilawa Barbara

    2015-01-01

    Paramagnetic centers in the two exemplary synthetic and natural dental biocompatible materials applied in implantology were examined by the use of an X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra were measured in the range of microwave power 2.2–70 mW. The aims of this work were to compare paramagnetic centers concentrations in different dental biocompatible materials and to determine the effect of microwave power on parameters of their EPR spectra. It i...

  7. Microbial deterioration and degradation of Polymeric materials

    Directory of Open Access Journals (Sweden)

    Krishna Mohan

    2010-12-01

    -bidi-theme-font:minor-bidi;}  Polymeric materials due to its structural versatility are widely used in aerospace applications, aviation and space industries. As they are potential source of carbon and energy for heterotrophic microorganisms including bacteria and fungi in several ways its biodegradation affect these industries. The information on degradability can provide fundamental information facilitating design and life-time analysis of materials. Literature survey shows that polymers which are susceptible to biofilm formation includes paints, adhesives, plastics, rubbers, sealants, FRPCMs, lubricating materials, fuels etc. Even though the understanding of polymer degradation has been advanced in recent years the subject is still inadequately addressed because of the lack of information available. The review focuses on polymer biodeterioration and biodegradation and its mechanisms, the types of microorganisms involved, the reactions of enzymes of importance in the biodegradation of polymers, consequences, of biodegradation, the factors involved in biodegradation of polymers and its prevention and the tests used to evaluate it.

  8. Light induced polymerization of resin composite restorative materials

    OpenAIRE

    Blažić Larisa; Marković Dubravka; Đurić Milanko

    2004-01-01

    Introduction Dimensional stability of polymer-based dental materials is compromised by polymerization reaction of the monomer. The conversion into a polymer is accompanied by a closer packing of molecules, which leads to volume reduction called curing contraction or polymerization shrinkage. Curing contraction may break the adhesion between the adhesive system and hard tooth tissues forming micrographs which may result in marginal deterioration, recurrent caries and pulp injury. Polymerizatio...

  9. Advanced Polymeric Materials for High-tech Innovations

    Institute of Scientific and Technical Information of China (English)

    TANG BenZhong

    2001-01-01

    @@ High technology is advancing our society and modernizing our life and advanced materials play an important role in the technological innovations. My research group has been working on the development of advanced polymeric materials and in this talk I will report our recent work on the creation of new conjugated polymers with novel molecular structures and unique materials properties.1-18 Our work include the design of molecular structures of monomeric building blocks, development of stable, effective and environmentally benign "green” polymerization catalysts, discovery of new polymerization reactions, synthesis of functional macromolecules, fabrication of nanodimensional composites, assembly and control of hierarchical structures, and construction of electrooptical devices. We have revealed the liquid crystallinity, light emission, photoconductivity, optical limiting, nano-hybridization, solvatochromism, optical activity, self-organization, and biological activity of the linear polyacetylenes and hyperbranched polyarylenes. The utilization of the advanced polymers and their interesting materials properties for high-tech innovations will be discussed.

  10. Advanced Polymeric Materials for High-tech Innovations

    Institute of Scientific and Technical Information of China (English)

    TANG; BenZhong

    2001-01-01

    High technology is advancing our society and modernizing our life and advanced materials play an important role in the technological innovations. My research group has been working on the development of advanced polymeric materials and in this talk I will report our recent work on the creation of new conjugated polymers with novel molecular structures and unique materials properties.1-18 Our work include the design of molecular structures of monomeric building blocks, development of stable, effective and environmentally benign "green” polymerization catalysts, discovery of new polymerization reactions, synthesis of functional macromolecules, fabrication of nanodimensional composites, assembly and control of hierarchical structures, and construction of electrooptical devices. We have revealed the liquid crystallinity, light emission, photoconductivity, optical limiting, nano-hybridization, solvatochromism, optical activity, self-organization, and biological activity of the linear polyacetylenes and hyperbranched polyarylenes. The utilization of the advanced polymers and their interesting materials properties for high-tech innovations will be discussed.  ……

  11. Arg-Gly-Asp (RGD) Modified Biomimetic Polymeric Materials

    Institute of Scientific and Technical Information of China (English)

    Xufeng NIU; Yuanliang WANG; Yanfeng LUO; Juan XIN; Yonggang LI

    2005-01-01

    The new generation of biomaterials focuses on the design of biomimetic polymeric materials that are capable of eliciting specific cellular responses and directing new tissue formation. Since Arg-Gly-Asp (RGD) sequences have been found to promote cell adhesion in 1984, numerous polymers have been functionalized with RGD peptides for tissue engineering applications. This review gave the advance in RGD modified biomimetic polymeric materials,focusing on the mechanism of RGD, the surface and bulk modification of polymer with RGD peptides and the evaluation in vitro and in vivo of the modified biomimetic materials.

  12. Tissue reaction to sealing materials: different view at biocompatibility

    Directory of Open Access Journals (Sweden)

    Ghanaati S

    2010-11-01

    Full Text Available Abstract The biodegradability of root canal sealers in areas other than the root canal system is crucial to the overall success rate of endodontic treatment. The aim of the present study was to investigate, the cell and tissue reaction to GuttaFlow and AHPlus, both in vitro and in vivo. For the in vitro experiments the materials were incubated with Human Periodontal Ligament Fibroblasts and cell proliferation and cytotoxicity analyses were performed. Additional fluorescence-microscope stainings were carried out in order to visualize cell growth and morphology. For assessment of the tissue reaction to the materials a subcutaneous implantation model in Wistar rats was employed and the inflammatory response to the materials was visualized by means of general and specific histology after 6 weeks. Human gingival fibroblasts proliferation seemed to be dependent upon dental material and cultivation time. After an incubation period of 96 hrs AHPlus proved to be significantly (p

  13. The Biocompatibility and Biostability of New Cardiovascular Materials and Devices

    Science.gov (United States)

    Stokes, Ken

    Evaluating a new material for use in an implantable device is a complicated business. ISO 14971 is designed to assist in determining device-risk assessment. ISO 10993 is intended to help steer one through the evaluation of materials for implantable devices. An FDA Guidance is available specifically for pacemaker leads, but may be helpful for other devices as well. However, completing a battery of in vitro and in vivo tests does not necessarily qualify a material for implant, because the in vivo environment cannot be duplicated in vitro. In vivo materials testing helps, but is still insufficient because the device may have its own issues. Device implants in animals may get one to human clinical studies and market release. Even after this stage, appropriate postmarket surveillance is necessary to know for sure how the device is really performing.

  14. Novel Biocompatible Material Based on Solid-State Modified Chitosan for Laser Stereolithography

    OpenAIRE

    P.S. Timashev; K.N. Bardakova; Т.S. Demina; G.I. Pudovkina; М.М. Novikov; М.А. Markov; D.S. Asyutin; L.F. Pimenova; Е.А. Svidchenko; А.М. Ermakov; I. I. Selezneva; V.К. Popov; N.А. Konovalov; Т.А. Akopova; А.B. Solovieva

    2015-01-01

    The aim of the investigation was to develop a novel biodegradable material based on chitosan synthesized by solid-state technoogy, and to create based on biocompatible three-dimensional cell-carrying scaffolds using laser stereolithography. Materials and Methods. Reactive systems were developed based on chitosan grafted with allyl, polyethylene glycol diacrylate, and the photoinitiator Irgacure 2959. The structures were obtained using laser stereolithography setting LS-120 (Institute on L...

  15. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2011-02-01

    Polymeric encapsulation materials are typically used in concentrating photovoltaic (CPV) modules to protect the cell from the field environment. Because it is physically located adjacent to the cell, the encapsulation is exposed to a high optical flux, often including light in the ultraviolet (UV) and infrared (IR) wavelengths. The durability of encapsulants used in CPV modules is critical to the technology, but is presently not well understood. This work seeks to identify the appropriate material types, field-induced failure mechanisms, and factors of influence (if possible) of polymeric encapsulation. These results will ultimately be weighed against those of future qualification and accelerated life test procedures.

  16. Polymeric materials for photoelectrochemical cells for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Aal, H.K. (King Fahd Univ. of Petroleum and Minerals, Dhahran (SA). Dept. of Chemical Engineering); Hassan, H.H. (Cairo Univ. (Egypt). Dept. of Physics); Mohamed, M.A.; Khairy, S.A. (National Research Center, Cairo (EG). Dept. of Solar Energy)

    1991-01-01

    Some filled-polymeric materials were selected and the properties of their electrical conduction were examined in order to investigate the possibility of using them as semiconductor electrodes for hydrogen production in photoelectrochemical cells (PEC). The activation energy and the corresponding wavelength are calculated for the polymeric materials proposed in the study. As a result, mixtures of butadiene acrylo-nitrile rubber (BNR) and polychloroprene (PCP) to which ZnO is added, proved to be potential candidates for making semiconductor electrodes for PEC used in hydrogen production. (Author).

  17. Biocompatibility of surgical implants

    Science.gov (United States)

    Kaelble, D. H.

    1979-01-01

    Method of selecting biocompatible materials for surgical implants uses fracture mechanic relationships and surface energies of candidate materials in presence of blood plasma. Technique has been used to characterize 190 materials by parameters that reflect their biocompatibility.

  18. Optimization of Microencapsulation Process for Self-Healing Polymeric Material

    International Nuclear Information System (INIS)

    A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was successfully prepared by in situ polymerization. The effect of diverse process parameters and ingredients on the morphology of the microcapsules was observed by SEM, optical microscopy (OM) and digital microscopy. Different techniques for the characterization of the chemical structure and the core content were considered such as FT-IR and 1H-NMR as well as the characterization of thermal properties by DSC. High yields of free flowing powder of spherical microcapsules were produced. The synthesized microcapsules can be incorporated into another polymeric host material. In the event the host material cracks due to excessive stress or strong impact, the microcapsules would rupture to release the DCPD, which could polymerize to repair the crack. (author)

  19. The Use of Nanoscaled Fibers or Tubes to Improve Biocompatibility and Bioactivity of Biomedical Materials

    OpenAIRE

    Fuzhai Cui; Qingling Feng; Yubo Fan; Bo Yu(Brookhaven National Lab); Lianwen Sun; Wei Liu; Rongrong Cui; Xiaoming Li; Fumio Watari

    2013-01-01

    Nanofibers and nanotubes have recently gained substantial interest for potential applications in tissue engineering due to their large ratio of surface area to volume and unique microstructure. It has been well proved that the mechanical property of matrix could be largely enhanced by the addition of nanoscaled fibers or tubes. At present, more and more researches have shown that the biocompatibility and bioactivity of biomedical materials could be improved by the addition of nanofibers or na...

  20. Biocompatible medical implant materials with binding sites for a biodegradable drug-delivery system

    OpenAIRE

    Al-Dubai H; Pittner G; Pittner F; Gabor F

    2011-01-01

    Haifa Al-Dubai1, Gisela Pittner1, Fritz Pittner1, Franz Gabor21Max F Perutz Laboratories, Department of Biochemistry, University of Vienna, Vienna, Austria; 2Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, University of Vienna, Vienna, AustriaAbstract: Feasibility studies have been carried out for development of a biocompatible coating of medical implant materials allowing the binding of biodegradable drug-delivery systems in a way that their reloading ...

  1. Novel Biocompatible Material Based on Solid-State Modified Chitosan for Laser Stereolithography

    Directory of Open Access Journals (Sweden)

    P.S. Timashev

    2015-09-01

    Full Text Available The aim of the investigation was to develop a novel biodegradable material based on chitosan synthesized by solid-state technoogy, and to create based on biocompatible three-dimensional cell-carrying scaffolds using laser stereolithography. Materials and Methods. Reactive systems were developed based on chitosan grafted with allyl, polyethylene glycol diacrylate, and the photoinitiator Irgacure 2959. The structures were obtained using laser stereolithography setting LS-120 (Institute on Laser and Information Technologies, Russian Academy of Sciences, Russia. Results. Partial replacement of chitosan amino groups by allyl groups (CТ-А and the introduction of polyethylene glycol diacrylate (PEG-DA as a crosslinking agent were found not to reduce the material biocompatibility. The metabolic activity determination of NCTC L929 cells using MTT assay showed that the samples under study to contain none water-soluble components toxic to mammalian cells. The samples based on CT-A and CT-A with a crosslinking agent PEG-DA are biocompatible and are able to support adhesion, spreading and proliferative activity of human mesenchymal stromal cells, but have significant differences in the extent and nature of the expression activation of gene markers for osteogenic differentiation path.

  2. Nuclear reactor safety. Qualification of polymeric materials

    International Nuclear Information System (INIS)

    A facility has been realized for nuclear qualification and extensive testing of material which are used (or could be used) in nuclear plants, mainly plastic materials (insulating, thightness, coatings). The test cell of reference accident simulation called CESAR facility was built to study the synergic effect between irradiation and thermodynamic and chemical conditions occuring in a reactor accident. This facility allow the reproduction in real size of time, temperature, pressure and irradiation found in the containment shell in case of primary coolant system failure

  3. Preparation of atomic oxygen resistant polymeric materials

    Science.gov (United States)

    Tortorelli, Victor J.; Hergenrother, P. M.; Connell, J. W.

    1991-01-01

    Polyphenyl quinoxalines (PPQs) are an important family of high performance polymers that offer good chemical and thermal stability coupled with excellent mechanical properties. These aromatic heterocyclic polymers are potentially useful as films, coatings, adhesives, and composite materials that demand stability in harsh environments. Our approach was to prepare PPQs with pendent siloxane groups using the appropriate chemistry and then evaluate these polymers before and after exposure to simulated atomic oxygen. Either monomer, the bis(o-diamine)s or the bis(alpha-diketone)s can be synthesized with a hydroxy group to which the siloxane chain will be attached. Several novel materials were prepared.

  4. Wheat B-starch based polymeric materials

    Czech Academy of Sciences Publication Activity Database

    Kotek, Jiří; Kruliš, Zdeněk; Šárka, E.

    2011-01-01

    Roč. 105, č. 9 (2011), s. 731. ISSN 0009-2770. [International Conference on Polysaccharides-Glycoscience /7./. 02.11.2011-04.11.2011, Prague] R&D Projects: GA ČR GA525/09/0607 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable plastic * polycaprolactone * B- starch Subject RIV: JI - Composite Materials

  5. Structure and transport properties in organized polymeric materials

    CERN Document Server

    Cheiellini, E

    1998-01-01

    This multi-authored book includes selected contributions reviewing the results achieved in the synthesis and characterization of organized polymeric materials. The focus is on competitive materials with liquid crystalline or electroconductive properties. The fine tuning of the properties offered by advanced chemical synthesis has been investigated by a large number of state-of-the-art techniques, including both microscopic (ESR, NMR, dielectrometry, fluorescence, IR, Raman spectroscopy) and macroscopic (calorimetric, mechanical) methodologies. The book also provides an updated coverage of the

  6. Measurement of thermal conductivity of polymeric nanocomposite materials

    OpenAIRE

    Gannoum, Misel

    2016-01-01

    A measuring device of the thermal conductivity of Polymeric nanocomposite materials is presented. This project is a continuation of a previous master student work. The goal of this project is to build a miniaturized version of the previous device in order to overturn certain limitations and improve its overall performance. The new device uses much smaller size samples, which ensures sample integrity/rigidity and saves material which in the case of nanoadditives may be expensive or scarce. In ...

  7. Micro-and nano-structured conducting polymeric materials

    Institute of Scientific and Technical Information of China (English)

    LU Gewu; CHEN Feng'en; WU Xufeng; QU Liangti; ZHANG Jiaxin; SHI Gaoquan

    2005-01-01

    Conducting polymeric materials with micro-/nano-structures have potential applications in fabrication of various optical, electronic, sensing and electrochemical devices. This is mainly because these materials not only possess the characteristics of conducting polymers, but also have special functions based on their micro- or nano-structures. In this review, we summarize the recent work on "soft" and "hard" template-guided syntheses of micro-/nano-structured conducting polymers and open up the prospects of the main trends in this field.

  8. Wheat B-starch based polymeric materials

    Czech Academy of Sciences Publication Activity Database

    Kotek, Jiří; Kruliš, Zdeněk; Šárka, E.

    Prague : Czech Chemical Society, 2011 - (Řápková, R.; Čopíková, J.; Šárka, E.), s. 37-39 ISBN 978-80-86238-90-6. [International Conference on Polysaccharides-Glycoscience /7./. Prague (CZ), 02.11.2011-04.11.2011] R&D Projects: GA ČR GA525/09/0607 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable plastic * polycaprolactone * B- starch Subject RIV: JI - Composite Materials

  9. New polymeric materials for vascular surgery

    OpenAIRE

    Cortecchia, Elisa

    2011-01-01

    The dramatic impact that vascular diseases have on human life quality and expectancy nowadays is the reason why both medical and scientific communities put great effort in discovering new and effective ways to fight vascular pathologies. Among the many different treatments, endovascular surgery is a minimally-invasive technique that makes use of X-ray fluoroscopy to obtain real-time images of the patient during interventions. In this context radiopaque biomaterials, i.e. materials able to abs...

  10. Research on the preparation, biocompatibility and bioactivity of magnesium matrix hydroxyapatite composite material.

    Science.gov (United States)

    Linsheng, Li; Guoxiang, Lin; Lihui, Li

    2016-08-12

    In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity. PMID:27567779

  11. Considerations for Electroactive Polymeric Materials and Actuators

    International Nuclear Information System (INIS)

    Ras Labs produces electroactive polymer (EAP) based materials and actuators that bend, swell, ripple and now contract (new development) with low electric input. This is an important attribute because of the ability of contraction to produce life-like motion. The mechanism of contraction is not well understood. Radionuclide-labeled experiments were conducted to follow the movement of electrolytes and water in these EAPs when activated. Extreme temperature experiments were performed on the contractile EAPs with very favorable results. One of the biggest challenges in developing these actuators, however, is the electrode-EAP interface because of the pronounced movement of the EAP. Plasma treatments of metallic electrodes were investigated in order to improve the attachment of the embedded electrodes to the EAP material. Surface analysis, adhesive testing, and mechanical testing were conducted to test metal surfaces and metal-polymer interfaces. The nitrogen plasma treatment of titanium produced a strong metal-polymer interface; however, oxygen plasma treatment of both stainless steel and titanium produced even stronger metal-polymer interfaces. Plasma treatment of the electrodes allows for the embedded electrodes and the EAP material of the actuator to work and move as a unit, with no detachment, by significantly improving the metal-polymer interface.

  12. [Electrochemical properties of biocompatible material hardness modifications on titanium and steel under mechanical loads].

    Science.gov (United States)

    Braun, W; Walter, U; Holbein, R; Thull, R

    2005-04-01

    Friction corrosion may appear between different implant components or between implant and hard tissue. The sliding micro movements induce fretting wear corrosion and have been recently reported as a cause of joint prostheses failure. A surface coating is desirable, that retains the mechanical properties of the substrate, offers good biocompatibility and improves the fretting corrosion resistance. In this study it could be demonstrated that tantalum and niobium coatings fulfill the requirements. On titanium substrates the coating decreases the abrasion against PMMA, an orthopedic relevant material. Furthermore, in the case of medical steel substrates the biocompatibility and the corrosion properties are improved. The better abrasion-resistance is minimizing the release of allergological critical particles like nickel and chromium. PMID:15884706

  13. Advances in radiation processing of polymeric materials

    International Nuclear Information System (INIS)

    In this paper we review recent advances in industrial applications of electron-beam irradiation in the field of polymer processing at the Takasaki Radiation Chemistry Research Establishment (TRCRE) of JAERI (Japan Atomic Energy Research Institute), and the Whiteshell Laboratories of AECL Research, Canada. Irradiation of a substrate with ionizing radiation produces free radicals through ionization and excitation events. The subsequent chemistry of these radicals is used in radiation processing as a substitute for conventional processing techniques based on heating and/or the addition of chemicals. The advantages of radiation processing include the formation of novel products with desirable material properties, favourable overall process economics and, often, environmental benefits

  14. Biocompatibility and cytotoxicity study of nanophotonic rigid gas permeable contact lens material

    International Nuclear Information System (INIS)

    Since materials on nanoscale have different characteristics from materials on macro scale their biocompatibility should be precisely and specifically investigated. Fullerenes, the third carbon allotrope, are one of the most used nanomaterials. The least stable and the most common is fullerene C60. One of the main disadvantages of fullerene is its low solubility in water. In order to make it soluble, it must be functionalized with polar groups such as -OH and -COOH. From all the water soluble fullerenes the most important ones are those with -OH groups attached named fullerols. We have developed new materials for contact lenses by adding fullerene (C60) and fullerol (C60(OH)24) into PMMA. The aim of our investigation was to compare the influences of those materials on aqueous solutions similar to tear film. For the analysis of the solutions we used opto-magnetic imaging and IR spectroscopy. The acquired spectrums were commented and compared with the standard contact lens material, which was analyzed by the same methods. The ISO 10993 cytotoxicity test on extract of nanophotonic material with incorporated C60 was done as well. This research contributes to better understanding of the biocompatibility of new rigid gas permeable contact lens materials.

  15. Synthesizing Smart Polymeric and Composite Materials

    Science.gov (United States)

    Gong, Chaokun

    Smart materials have been widely investigated to explore new functionalities unavailable to traditional materials or to mimic the multifunctionality of biological systems. Synthetic polymers are particularly attractive as they already possess some of the attributes required for smart materials, and there are vast room to further enhance the existing properties or impart new properties by polymer synthesis or composite formulation. In this work, three types of smart polymer and composites have been investigated with important new applications: (1) healable polymer composites for structural application and healable composite conductor for electronic device application; (2) conducting polymer polypyrrole actuator for implantable medical device application; and (3) ferroelectric polymer and ceramic nanoparticles composites for electrocaloric effect based solid state refrigeration application. These application entail highly challenging materials innovation, and my work has led to significant progress in all three areas. For the healable polymer composites, well known intrinsically healable polymer 2MEP4F (a Diels-Alder crosslinked polymer formed from a monomer with four furan groups and another monomer with two maleimide groups) was first chosen as the matrix reinforced with fiber. Glass fibers were successfully functionalized with maleimide functional groups on their surface. Composites from functionalized glass fibers and 2MEP4F healable polymer were made to compare with composites made from commercial carbon fibers and 2MEP4F polymer. Dramatically improved short beam shear strength was obtained from composite of functionalized glass fibers and 2MEP4F polymer. The high cost of 2MEP4F polymer can potentially limit the large-scale application of the developed healable composite, we further developed a new healable polymer with much lower cost. This new polymer was formed through the Diels-Alder crosslinking of poly(furfuryl alcohol) (PFA) and 1,1'-(Methylenedi-4

  16. Biocompatibilidade dos materiais em Ortodontia: mito ou realidade? Biocompatibility of orthodontic materials: myth or reality?

    Directory of Open Access Journals (Sweden)

    Luciane Macedo de Menezes

    2009-04-01

    Full Text Available O objetivo deste trabalho é apresentar uma revisão sobre os conceitos relacionados à biocompatibilidade dos materiais empregados em Ortodontia. Fatos relacionados às reações de hipersensibilidade aos diversos materiais ortodônticos são discutidos, sendo apresentadas as condutas recomendáveis nestas situações.The aim of this paper is to present a review on the biocompatibility of orthodontic materials. Hypersensitivity reactions to these materials are discussed and the recommended conduct in this kind of situation are presented.

  17. New polymeric materials for photonic applications: Preliminary investigations

    Science.gov (United States)

    Aldea, Anca; Albu, Ana-Maria; Rau, Ileana

    2016-06-01

    In this paper we propose two types of polymeric materials synthesized by us suitable to interact by assembling with DNA in order to obtain new NLO biomaterials. The first polymer is a methacrylic chromophore with azobenzene groups and carbazolyl sequences known for their carrying principles while the second one is a copolymer of the methacrylic chromophore with a N-substituted amide. The N-substituted amide is N-acryloyl morpholine already used in biological application and also because is compatible with DNA. Spectral characterization of these materials showed charge transfer interactions depending on the solvent. The results obtained indicate that these new polymeric/copolymeric chromophores could interact with DNA in order to obtain biomaterials for photonic applications.

  18. Polymeric optical waveguide devices exploiting special properties of polymer materials

    Science.gov (United States)

    Oh, Min-Cheol; Chu, Woo-Sung; Shin, Jin-Soo; Kim, Jun-Whee; Kim, Kyung-Jo; Seo, Jun-Kyu; Lee, Hak-Kyu; Noh, Young-Ouk; Lee, Hyung-Jong

    2016-03-01

    Optical polymer materials have many unique features that are unavailable in other inorganic optical materials. These include large thermo-optic effect with low thermal conductivity, index tunability by solution blending, structural diversity, freestanding flexibility, and controllable birefringence. Various functional integrated optic devices have been investigated by our group based on the specialties of fluorinated polymer material, which include extremely low crosstalk integrated optics, strain-controlled flexible waveguide tunable lasers, and birefringence-tuned polarization controllers. They have been demonstrated to have good performance, large fabrication tolerance, and high reliability, and they will be important building blocks for extending the application territory of polymeric optical waveguide devices.

  19. Biodegradable polymeric materials based on B-starch

    Czech Academy of Sciences Publication Activity Database

    Ponyrko, Sergii; Kruliš, Zdeněk; Kotek, Jiří

    Halle (Saale) : Martin Luther University Halle-Wittenberg, 2010 - (Radusch, H.; Fiedler, L.). s. 91 ISBN 978-3-86829-282-4. [International Scientific Conference on Polymeric Materials /14./. 15.09.2010-17.09.2010, Halle (Saale)] R&D Projects: GA ČR GA525/09/0607 Institutional research plan: CEZ:AV0Z40500505 Keywords : starch -derived polymers * biodegradability * B- starch Subject RIV: GM - Food Processing

  20. Synthesis and characterization of new polymeric materials for advanced applications

    OpenAIRE

    Sanna, Roberta

    2014-01-01

    The main aim of this thesis was to synthesize and characterize new kinds of polymeric nanocomposite materials, including stimuli responsive hydrogels, organic-inorganic interpenetrating polymer networks, polyacrylates and polyurethanes. Specifically, this work was divided in two main threads: in the first one, electric field-, ionic force-, pH- and thermo-responsive hydrogels were prepared, whose thermal and mechanical properties, as well as the swelling behavior were strongly improved by the...

  1. Wind erosion control of soils using polymeric materials

    OpenAIRE

    Mohammad Movahedan; Nader Abbasi; Majid Keramati

    2012-01-01

    Wind erosion of soils is one of the most important problems in environment and agriculture which could affects several fields. Agricultural lands, water reservoires, irrigation canals, drains and etc. may be affected by wind erosion and suspended particles. As a result wind erosion control needs attention in arid and semi-arid regions. In recent years, some polymeric materials have been used for improvement of structural stability, increasing aggregate stability and soil stabilization, though...

  2. Novel POSS-PCU Nanocomposite Material as a Biocompatible Coating for Quantum Dots.

    Science.gov (United States)

    Rizvi, Sarwat B; Yang, Shi Yu; Green, Mark; Keshtgar, Mo; Seifalian, Alexander M

    2015-12-16

    Quantum dots (QDs) are fluorescent nanoparticles with unique photophysical properties that enable them to potentially replace traditional organic dyes and fluorescent proteins in various bioimaging applications. However, the inherent toxicity of their cores based on cadmium salts limits their widespread biomedical use. We have developed a novel nanocomposite polymer emulsion based on polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) that can be used to coat quantum dots to nullify their toxicity and enhance photostability. Here we report the synthesis and characterization of a novel POSS-PCU nanocomposite polymer emulsion and describe its application for coating QDs for biological application. The polymer was synthesized by a process of emulsion polymerization and formed stable micelles of ∼33 nm in diameter. CdTe/CdS/ZnS QDs were efficiently stabilized by the polymer emulsion through encapsulation within the polymer micelles. Characterization studies showed no significant change in the unique photophysical properties of QDs after coating. The polymer was biocompatible to HepG2, HUVECs, and mouse skeletal muscle cells at 2.5% after 24 h exposure on in vitro testing. Polymer encapsulated QDs showed enhanced photostability on exposure to high degrees of UV irradiation and air as well as significantly reduced cytotoxicity on exposure to HepG2 cells at 30 μg/mL for 24 h. We have therefore concluded that the POSS-PCU polymer emulsion has the potential to make a biocompatible and photostable coating for QDs enabling a host of biomedical applications to take this technology to the next level. PMID:26439600

  3. Biocompatible self-assembly of nano-materials for Bio-MEMS and insect reconnaissance.

    Energy Technology Data Exchange (ETDEWEB)

    Brozik, Susan Marie; Cesarano, Joseph, III; Brinker, C. Jeffrey; Dunphy, Darren Robert; Sinclair, Michael B.; Manginell, Monica; Ashley, Carlee E. (University of New Mexico, Albuquerque, NM); Timlin, Jerilyn Ann; Werner-Washburne, Margaret C. (University of New Mexico, Albuquerque, NM); Calvert, Paul Davidson (University of Massachusetts - Dartmouth, Dartmouth, MA); Hartenberger, Tamara N.; Flemming, Jeb Hunter; Baca, Helen Kennicott (University of New Mexico, Albuquerque, NM)

    2003-12-01

    This report summarizes the development of new biocompatible self-assembly procedures enabling the immobilization of genetically engineered cells in a compact, self-sustaining, remotely addressable sensor platform. We used evaporation induced self-assembly (EISA) to immobilize cells within periodic silica nanostructures, characterized by unimodal pore sizes and pore connectivity, that can be patterned using ink-jet printing or photo patterning. We constructed cell lines for the expression of fluorescent proteins and induced reporter protein expression in immobilized cells. We investigated the role of the abiotic/biotic interface during cell-mediated self-assembly of synthetic materials.

  4. PREFACE: 9th National Symposium on Polymeric Materials (NSPM 2009)

    Science.gov (United States)

    Ali, Aidy; Salit, Sapuan

    2010-07-01

    NSPM 2009 is the formal proceedings of the 9th National Symposium on Polymeric Materials held in Residence Hotel Uniten Bangi on 14-16 December 2009. It is also organised with The Plastics and Rubber Institute Malaysia PRIM. The symposium proceedings consists of 94 papers covering a large number of issues on experimental and analytical studies of polymeric materials. The objectives of the symposium are to review the state-of-the art, present and latest findings and exchange ideas among engineers, researchers and practitioners involved in this field. We strongly hope the outcomes of this symposium will stimulate and enhanced the progress of experimental and analytical studies on polymeric materials as well as contribute to the fundamental understanding in related fields. After careful refereeing of all manuscripts, 15 papers were selected for publications in this issue. Another 20 papers were selected for publication in Pertanika Journal of Science and Technology (PJST). The content of the material and its rapid dissemination was considered to be more important than its form. We are grateful to all the authors for their papers and presentations in this symposium. They are also the ones who help make this symposium possible through their hard work in the preparation of the manuscripts. We would also like to offer our sincere thanks to all the invited speakers who came to share their knowledge with us. We would also like to acknowledge the untiring efforts of the reviewers, research assistants and students in meeting deadlines and for their patience and perseverance. We are indeed honoured to associate this event with Department of Mechanical and Manufacturing, and Faculty of Engineering, Universiti Putra Malaysia. Finally, we appreciate the sponsor support provided by Faculty of Engineering, The Plastics and Rubber Institute Malaysia (PRIM) and PETRONAS Malaysia. Thank you all. Editors: Aidy Ali and S M Sapuan

  5. Polymeric Bicontinuous Microemulsions as Templates for Nanostructured Materials

    Science.gov (United States)

    Jones, Brad Howard

    Ternary blends of two homopolymers and a diblock copolymer can self-assemble into interpenetrating, three dimensionally-continuous networks with a characteristic length scale of ˜ 100 nm. In this thesis, it is shown that these liquid phases, known as polymeric bicontinuous microemulsions (BμE), can be designed as versatile precursors to nanoporous materials having pores with uniform sizes of ˜ 100 nm. The model blends from which the porous materials are derived are composed of polyethylene (PE) and a sacrificial polyolefin. The liquid BμE structure is captured by crystallization of the PE, and a three-dimensionally continuous pore network with a narrow pore size distribution is generated by selective extraction of the sacrificial component. The original BμE structure is retained in the resultant nanoporous PE. This monolithic material is then used as a template in the synthesis of other nanoporous materials for which structural control at the nm scale has traditionally been difficult to achieve. These materials, which include a high-temperature ceramic, polymeric thermosets, and a conducting polymer, are produced by a simple nanocasting process, providing an inverse replica of the PE template. On account of the BμE structure of the template, the product materials also possess three-dimensionally continuous pore networks with narrow size distributions centered at ˜ 100 nm. The PE template is further used as a template for the production of hierarchically structured inorganic and polymeric materials by infiltration of mesostructured compounds into its pore network. In the former case, a hierarchically porous SiO2 material is demonstrated, simultaneously possessing two discrete, bicontinuous pore networks with sizes differing by over an order of magnitude. Finally, the templating procedures are extended to thin films supported on substrates and novel conductive polymer films are synthesized. The work described herein represents an unprecedented suite of

  6. Enhanced laser action of Perylene-Red doped polymeric materials

    OpenAIRE

    Garcia-Moreno, I.; Costela, A.; Pintado-Sierra, Mercedes; Martin, Virginia; Sastre, Roberto

    2009-01-01

    The laser action of Perylene-Red doped in linear, crosslinked, fluorinated and sililated polymeric materials is reported. The purity of dye was found to be a key factor to enhance its solid-state laser behaviour. The samples were transversely pumped at 532 nm, with 5.5 mJ/pulse and 10 Hz repetition rate. Perylene-Red doped copolymers of methyl methacrylate with a 10 vol% proportion of 2,2,2-trifluoroethyl-methacrylate exhibited a lasing efficiency of 26% with a high photosta...

  7. Fluoropolymer materials and architectures prepared by controlled radical polymerizations

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Jankova Atanasova, Katja; Hvilsted, Søren

    2007-01-01

    This review initially summarizes the mechanisms, merits and limitations of the three controlled radical polymerizations: nitroxide mediated polymerization (NMP), atom transfer radical polymerization (ATRP) or metal catalyzed living radical polymerization, and reversible addition–fragmentation chain...... transfer (RAFT) polymerization. This is followed by two parts, one dealing with homo- and copolymerizations of fluorinated methacrylates and acrylates, and a second where fluorinated styrenes, alone or in combination with other monomers, are the main issues. In these parts, initiators (including...

  8. Biocompatible medical implant materials with binding sites for a biodegradable drug-delivery system

    Directory of Open Access Journals (Sweden)

    Al-Dubai H

    2011-10-01

    Full Text Available Haifa Al-Dubai1, Gisela Pittner1, Fritz Pittner1, Franz Gabor21Max F Perutz Laboratories, Department of Biochemistry, University of Vienna, Vienna, Austria; 2Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, University of Vienna, Vienna, AustriaAbstract: Feasibility studies have been carried out for development of a biocompatible coating of medical implant materials allowing the binding of biodegradable drug-delivery systems in a way that their reloading might be possible. These novel coatings, able to bind biodegradable nanoparticles, may serve in the long run as drug carriers to mediate local pharmacological activity. After biodegradation of the nanoparticles, the binding sites could be reloaded with fresh drug-delivering particles. As a suitable receptor system for the nanoparticles, antibodies are anchored. The design of the receptor is of great importance as any bio- or chemorecognitive interaction with other components circulating in the blood has to be avoided. Furthermore, the binding between receptor and the particles has to be strong enough to keep them tightly bound during their lifetime, but on the other hand allow reloading after final degradation of the particles. The nanoparticles suggested as a drug-delivery system for medical implants can be loaded with different pharmaceuticals such as antibiotics, growth factors, or immunosuppressives. This concept may enable the changing of medication, even after implantation of the medical device, if afforded by patients’ needs.Keywords: antibody immobilization, biocompatible coating, chitosan nanoparticles, drug targeting, medical device

  9. Polymeric nanoparticles produced by physico-chemical methods: general principles and application to biocompatible and biodegradable nanoparticles for biomedical applications

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Petr; Jäger, Eliezer; Jäger, Alessandro; Etrych, Tomáš; Chytil, Petr; Jigounov, Alexander; Říhová, Blanka; Ulbrich, Karel

    Bahía Blanca : PLAPIQUI (UNS - CONICET), 2011. CP-01. [Simposio Argentino de Polímeros /9./ - SAP 2011. 15.11.2011-18.11.2011, Bahía Blanca] R&D Projects: GA ČR GAP208/10/1600; GA ČR GA202/09/2078 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50200510 Keywords : radical polymerization * block copolymer * graft copolymer Subject RIV: CF - Physical ; Theoretical Chemistry

  10. Engineering analysis of diamond-like carbon coated polymeric materials for biomedical applications.

    Science.gov (United States)

    Alanazi, A; Nojiri, C; Kido, T; Noguchi, T; Ohgoe, Y; Matsuda, T; Hirakuri, K; Funakubo, A; Sakai, K; Fukui, Y

    2000-08-01

    Diamond-like carbon (DLC) films have received much attention recently owing to their properties, which are similar to diamond: hardness, thermal conductivity, corrosion resistance against chemicals, abrasion resistance, good biocompatibility, and uniform flat surface. Furthermore, DLC films can be deposited easily on many substrates for wide area coat at room temperature. DLC films were developed for applications as biomedical materials in blood contacting-devices (e.g., rotary blood pump) and showed good biocompatibility for these applications. In this study, we investigated the surface roughness by Atomic Force Microscopy (AFM) and Hi-vision camera, SEM for surface imaging. The DLC films were produced by radio frequency glow discharge plasma decomposed of hydrocarbon gas at room temperature and low pressure (53 Pa) on several kinds of polycarbonate substrates. For the evaluation of the relation between deposition rate and platelet adhesion that we investigated in a previous study, DLC films were deposited at the same methane pressure for several deposition times, and film thickness was investigated. In addition, the deposition rate of DLC films on polymeric substrates is similar to the deposition rate of those deposited on Si substrates. There were no significant differences in substrates' surface roughness that were coated by DLC films in different deposition rates (16-40 nm). The surface energy and the contact angle of the DLC films were investigated. The chemical bond of DLC films also was evaluated. The evaluation of surface properties by many methods and measurements and the relationship between the platelet adhesion and film thickness is discussed. Finally, the presented DLC films appear to be promising candidates for biomedical applications and merit investigation. PMID:10971249

  11. Development of deodorizing materials by radiation graft polymerization

    International Nuclear Information System (INIS)

    With the development of society, the countermeasures for service water and sewerage in large cities and the environment preservation in industrial districts become difficult as their scale becomes larger. There are many unsolved problems, for example photochemical smog due to harmful gases, exhaust gas from automobiles, and smell of toilets and home waste water. The deodorizing materials used so far are mainly inorganic substances, and their ability of adsorbing harmful gases is very low. Besides, those are mostly granular, and limited in the formability. Therefore, it is expected to develop the fibrous adsorbent which has large adsorbing surface area and is easy to make filters. The chemical structures of the compounds having smell are shown. Eight legal bad smell substances which exert large influence to environment even in very small amount are designated. In this paper, the method of introducing functional radicals into existing fiber materials by the application of radiation graft polymerization process and the test of removing smelling compositions by using the obtained resin are reported. The experimental method, and the results of radiation graft polymerization, the adsorption of basic gases and acid gases, and gas flow test are described. (K.I.)

  12. Tribology of polymeric nanocomposites friction and wear of bulk materials and coatings

    CERN Document Server

    Friedrich, Klaus

    2013-01-01

    Tribology of Polymeric Nanocomposites provides a comprehensive description of polymeric nanocomposites, both as bulk materials and as thin surface coatings, and provides rare, focused coverage of their tribological behavior and potential use in tribological applications. Providing engineers and designers with the preparation techniques, friction and wear mechanisms, property information and evaluation methodology needed to select the right polymeric nanocomposites for the job, this unique book also includes valuable real-world examples of polymeric nanocomposites in a

  13. Dynamic Mechanical Behavior of a Novel Polymeric Composite Damping Material

    Institute of Scientific and Technical Information of China (English)

    Cheng ZHANG; Jiang Feng SHENG; Chun An MA

    2005-01-01

    The dynamic mechanical behavior of a novel polymeric composite damping material has been investigated in this article. The composite consists of chlorinated polyethylene (CPE),N,N-dicyclohexyl-2-benzothiazolylsufenamide (DZ), 4,4'-thio-bis(3-methyl-6-tert-buthylphenol)(BPSR) and vapor-grown carbon fiber (VGCF). It is found that either the position or the intensity of damping peak can be controlled by changing the composition of CPE/DZ/BPSR composite. Within a certain composition region, damping peak maximum depends on CPE/DZ ratio, whereas damping peak position is controlled by BPSR content. Moreover, the improvement of storage modulus can be achieved by incorporation of VGCF. These results may imply that a damping material possessing both good damping properties and high strength can be designed and obtained.

  14. Development of foamed Inorganic Polymeric Materials based on Perlite

    Science.gov (United States)

    Tsaousi, G.-M.; Douni, I.; Taxiarchou, M.; Panias, D.; Paspaliaris, I.

    2016-04-01

    This work deals with the development of lightweight geopolymeric boards for use in construction sector utilizing a solid perlitic waste as the main raw material. Hydrogen peroxide (H2O2) was used for the foaming of geopolymeric pastes and the production of porous and lightweight inorganic polymeric materials. The effect of geopolymeric synthesis parameters, such as the composition of activator and the curing conditions, on paste's properties that affect the foaming process, such as setting time and viscosity, were studied in detailed. Finally, the effects of H2O2 concentration on the properties (apparent density and % cell volume) and the microstructure of foamed boards were also studied. The produced porous boards have effective densities in-between 540 - 900 Kg/m3 and the thermal conductivity of the optimum product is 0.08 W/mK. Based on their properties, the developed lightweight geopolymeric boards have high potential to be used as building elements in construction industry.

  15. Polymeric foam-ferromagnet composites as smart lightweight materials

    Science.gov (United States)

    D’Auria, M.; Davino, D.; Pantani, R.; Sorrentino, L.

    2016-05-01

    A new class of lightweight smart materials based on a polymeric matrix with embedded magnetic micro-particles was developed. The application of a magnetic field (MF) during the foaming of samples induced, along the MF lines, the alignment of magnetic particles dispersed in the polymer thus forming chain-like reinforcing structures. The aligned micro-particles induced an anisotropic mechanical behaviour, strongly improving the mechanical stiffness and strength along the MF direction compared to unfilled systems. Most notably, the chain-like structures imparted a magneto-sensitive behaviour to the lightweight materials. In fact, foams showed a direct relationship between the foams elastic response and the intensity as well as the shape of the time dependent MF applied during their magneto-elastic characterisation. This magneto-elastic behaviour has been obtained at low MF strength (below 200 kA m‑1).

  16. Preparation, tribological properties and biocompatibility of fluorinated graphene/ultrahigh molecular weight polyethylene composite materials

    Science.gov (United States)

    Xu, L.; Zheng, Y.; Yan, Z.; Zhang, W.; Shi, J.; Zhou, F.; Zhang, X.; Wang, J.; Zhang, J.; Liu, B.

    2016-05-01

    Fluorinated graphene (FG)/ultra-high molecular weight polyethylene (UHMWPE) composites were successfully prepared by ultrasonic dispersion and liquid thermoforming method. The mechanical and tribological properties of pure UHMWPE and FG/UHMWPE composites were investigated using micro-hardness tester and high-speed reciprocating friction tester. The results showed that: adding FG could not only increase the micro-hardness of the composites, but also decrease the wear volume of the composite significantly. The friction coefficients of the composites were also reduced with the increasing of FG content. In addition, the MC3T3-E1 cells adhered and grew well on the surface of the FG/UHMWPE composites as observed by SEM and fluorescence microscope, indicating the addition of FG did not affect the morphology and activity of the cells. The FG/UHMWPE composites exhibited excellent mechanical properties, tribological properties and biocompatibility, which could be used as the potential artificial joint replacement material.

  17. Entrapping quercetin in silica/polyethylene glycol hybrid materials: Chemical characterization and biocompatibility.

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Nocera, Paola; Piccolella, Simona; Pacifico, Severina

    2016-11-01

    Sol-gel synthesis was exploited to entrap quercetin, a natural occurring antioxidant polyphenol, in silica-based hybrid materials, which differed in their polyethylene glycol (PEG) content (6, 12, 24 and 50wt%). The materials obtained, whose nano-composite nature was ascertained by Scanning Electron Microscopy (SEM), were chemically characterized by Fourier Transform InfraRed (FT-IR) and UV-Vis spectroscopies. The results prove that a reaction between the polymer and the drug occurred. Bioactivity tests showed their ability to induce hydroxyapatite nucleation on the sample surfaces. The direct contact method was applied to screen the cytotoxicity of the synthetized materials towards fibroblast NIH 3T3 cells, commonly used for in vitro biocompatibility studies, and three nervous system cell lines (neuroblastoma SH-SY5Y, glioma U251, and pheochromocytoma PC12 cell lines), adopted as models in oxidative stress related studies. Using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay NIH 3T3 proliferation was assessed and the morphology was not compromised by direct exposure to the materials. Analogously, PC-12, and U-251 cell lines were not affected by new materials. SH-SY5Y appeared to be the most sensitive cell line with cytotoxic effects of 20-35%. PMID:27524014

  18. Reducing the cytotoxicity of inhalable engineered nanoparticles via in situ passivation with biocompatible materials

    Energy Technology Data Exchange (ETDEWEB)

    Byeon, Jeong Hoon, E-mail: postjb@yu.ac.kr [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Park, Jae Hong; Peters, Thomas M. [Department of Occupational and Environmental Health, University of Iowa, IA 52242 (United States); Roberts, Jeffrey T., E-mail: jtrob@purdue.edu [Department of Chemistry, Purdue University, IN 47907 (United States)

    2015-07-15

    Highlights: • The cytotoxicity of model welding particles was modulated through in situ passivation. • Model welding particles were incorporated with chitosan nanoparticles for passivation. • In vitro assay revealed that the passivated particles had a lower cytotoxicity. • Passivation with chitosan adhesive or graphite paste could also reduce cytotoxicity. • This method would be suitable for efficient reduction of inhalable toxic components. - Abstract: The cytotoxicity of model welding nanoparticles was modulated through in situ passivation with soluble biocompatible materials. A passivation process consisting of a spark discharge particle generator coupled to a collison atomizer as a co-flow or counter-flow configuration was used to incorporate the model nanoparticles with chitosan. The tested model welding nanoparticles are inhaled and that A549 cells are a human lung epithelial cell line. Measurements of in vitro cytotoxicity in A549 cells revealed that the passivated nanoparticles had a lower cytotoxicity (>65% in average cell viability, counter-flow) than the untreated model nanoparticles. Moreover, the co-flow incorporation between the nanoparticles and chitosan induced passivation of the nanoparticles, and the average cell viability increased by >80% compared to the model welding nanoparticles. As a more convenient way (additional chitosan generation and incorporation devices may not be required), other passivation strategies through a modification of the welding rod with chitosan adhesive and graphite paste did also enhance average cell viability (>58%). The approach outlined in this work is potentially generalizable as a new platform, using only biocompatible materials in situ, to treat nanoparticles before they are inhaled.

  19. Reducing the cytotoxicity of inhalable engineered nanoparticles via in situ passivation with biocompatible materials

    International Nuclear Information System (INIS)

    Highlights: • The cytotoxicity of model welding particles was modulated through in situ passivation. • Model welding particles were incorporated with chitosan nanoparticles for passivation. • In vitro assay revealed that the passivated particles had a lower cytotoxicity. • Passivation with chitosan adhesive or graphite paste could also reduce cytotoxicity. • This method would be suitable for efficient reduction of inhalable toxic components. - Abstract: The cytotoxicity of model welding nanoparticles was modulated through in situ passivation with soluble biocompatible materials. A passivation process consisting of a spark discharge particle generator coupled to a collison atomizer as a co-flow or counter-flow configuration was used to incorporate the model nanoparticles with chitosan. The tested model welding nanoparticles are inhaled and that A549 cells are a human lung epithelial cell line. Measurements of in vitro cytotoxicity in A549 cells revealed that the passivated nanoparticles had a lower cytotoxicity (>65% in average cell viability, counter-flow) than the untreated model nanoparticles. Moreover, the co-flow incorporation between the nanoparticles and chitosan induced passivation of the nanoparticles, and the average cell viability increased by >80% compared to the model welding nanoparticles. As a more convenient way (additional chitosan generation and incorporation devices may not be required), other passivation strategies through a modification of the welding rod with chitosan adhesive and graphite paste did also enhance average cell viability (>58%). The approach outlined in this work is potentially generalizable as a new platform, using only biocompatible materials in situ, to treat nanoparticles before they are inhaled

  20. The effect of polymeric chain-like structure on the degradation and cellular biocompatibility of calcium polyphosphate

    International Nuclear Information System (INIS)

    Three-dimensional porous calcium polyphosphate (CPP) scaffolds were fabricated in the present work. We investigated the degradation mechanism of CPP from the viewpoint of polymeric structure and the effects of different polymeric structure on cell viability. By controlling the sintering temperature and altering the proportion of hydrolytic groups (Q1 groups) in polyphosphate chain, CPP can be obtained respectively with different degradation rate. The results suggested that with increasing sintering temperature, the proportion of Q1 groups in polyphosphate chain decreased. CPP sintered at 550 deg. C had 15.1% Q1 groups in polyphosphate chain, while CPP sintered at 650 deg. C and 750 deg. C exhibited 10.5 and 8.3%, respectively. During immersion in simulated body fluid (SBF) for 30 days, the weight loss of CPP sintered at 550 deg. C was about 80%, while CPP sintered at 650 deg. C and 750 deg. C degraded by only 8% and 5%. Cell viability test results showed that the porous CPP did not exert cytotoxicity effect on the cells after being cultured 6 days. Due to the lower degradation rate, CPP sintered at 750 deg. C showed better cell attachment and proliferation as well as higher cell density. These findings may provide an approach to study and achieve controllable degradation of CPP, and explore more biomedical applications

  1. Biocompatibility and characterisation of a candidate microelectrode material for biosensor applications

    International Nuclear Information System (INIS)

    Recent advances in microcircuit technology have enabled the fabrication of Multiple Microelectrode Arrays (MEAs) for investigating the characteristics of networks of neuronal cells either in vivo or in vitro. When producing a MEA materials used must be corrosion resistant, have low electrical impedance and the materials must be biocompatible. Existing MEA's have limited life spans, relatively high impedance values and limited uses. Thus creating a requirement for new MEA technology. TiN thin films have become increasingly useful in a wide variety of applications, due to their nature, which includes chemical stability, high hardness, excellent wear and electrical properties and also biocompatibility. The favourable electrical and biocompatibility characteristics of thin films of TiN make them a possible candidate for use in a MEA. TiN thin films can be deposited by a number of methods including evaporation, ion plating and sputtering. The method of deposition, along with process parameters used can have a marked effect on the characteristics of TiN films, including changes in preferred orientation, hardness and wear and also biocompatibility. TiN thin films were deposited onto glass substrates by pulsed DC reactive sputtering of a Ti target, with Argon and nitrogen gas mixtures and labelled Type I TiN films. Also industrial TIN films deposited by Arc Ion plating were carefully selected for comparison and labelled Type II TiN films. The microstructure, composition, surface chemistry, surface topography and roughness were studied using X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Atomic Force Microscopy (AFM) and Profilometry. Type I TIN films showed a surface topography similar to Zone I and Type II TiN films showed a surface topography similar to Zone 2 of the Movchan and Dernchishin structure zone model for sputtered films. XPS showed that the surface composition of all TiN films was predominantly TiO2, TiN and TiNxOy. Significant differences in

  2. Acoustical characterization and parameter optimization of polymeric noise control materials

    Science.gov (United States)

    Homsi, Emile N.

    2003-10-01

    The sound transmission loss (STL) characteristics of polymer-based materials are considered. Analytical models that predict, characterize and optimize the STL of polymeric materials, with respect to physical parameters that affect performance, are developed for single layer panel configuration and adapted for layered panel construction with homogenous core. An optimum set of material parameters is selected and translated into practical applications for validation. Sound attenuating thermoplastic materials designed to be used as barrier systems in the automotive and consumer industries have certain acoustical characteristics that vary in function of the stiffness and density of the selected material. The validity and applicability of existing theory is explored, and since STL is influenced by factors such as the surface mass density of the panel's material, a method is modified to improve STL performance and optimize load-bearing attributes. An experimentally derived function is applied to the model for better correlation. In-phase and out-of-phase motion of top and bottom layers are considered. It was found that the layered construction of the co-injection type would exhibit fused planes at the interface and move in-phase. The model for the single layer case is adapted to the layered case where it would behave as a single panel. Primary physical parameters that affect STL are identified and manipulated. Theoretical analysis is linked to the resin's matrix attribute. High STL material with representative characteristics is evaluated versus standard resins. It was found that high STL could be achieved by altering materials' matrix and by integrating design solution in the low frequency range. A suggested numerical approach is described for STL evaluation of simple and complex geometries. In practice, validation on actual vehicle systems proved the adequacy of the acoustical characterization process.

  3. A review of the methods used to study biocompatibility of Portland cement-derived materials used in dentistry

    OpenAIRE

    Camilleri, Josette

    2006-01-01

    Advanced restorative dentistry may necessitate the need for surgical intervention to the infected root apex. Once access to the root end is achieved, the root apex is resected and filled with a dental restorative material. The materials currently in use are not satisfactory due to inadequate biocompatibility and failure to achieve desirable properties in an aqueous environment. With the introduction of a new material, essentially Portland cement used in the building industry, these desirable ...

  4. A biocompatible hybrid material with simultaneous calcium and strontium release capability for bone tissue repair.

    Science.gov (United States)

    Almeida, J Carlos; Wacha, András; Gomes, Pedro S; Alves, Luís C; Fernandes, M Helena Vaz; Salvado, Isabel M Miranda; Fernandes, M Helena R

    2016-05-01

    The increasing interest in the effect of strontium in bone tissue repair has promoted the development of bioactive materials with strontium release capability. According to literature, hybrid materials based on the system PDMS-SiO2 have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS-SiO2-CaO-SrO, was prepared with the incorporation of 0.05mol of titanium per mol of SiO2. Calcium and strontium were added using the respective acetates as sources, following a sol-gel technique previously developed by the present authors. The obtained samples were characterized by FT-IR, solid-state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studies were performed by immersion of the samples in Kokubo's SBF for different periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed samples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity. PMID:26952443

  5. Quantitative property-structural relation modeling on polymeric dielectric materials

    Science.gov (United States)

    Wu, Ke

    Nowadays, polymeric materials have attracted more and more attention in dielectric applications. But searching for a material with desired properties is still largely based on trial and error. To facilitate the development of new polymeric materials, heuristic models built using the Quantitative Structure Property Relationships (QSPR) techniques can provide reliable "working solutions". In this thesis, the application of QSPR on polymeric materials is studied from two angles: descriptors and algorithms. A novel set of descriptors, called infinite chain descriptors (ICD), are developed to encode the chemical features of pure polymers. ICD is designed to eliminate the uncertainty of polymer conformations and inconsistency of molecular representation of polymers. Models for the dielectric constant, band gap, dielectric loss tangent and glass transition temperatures of organic polymers are built with high prediction accuracy. Two new algorithms, the physics-enlightened learning method (PELM) and multi-mechanism detection, are designed to deal with two typical challenges in material QSPR. PELM is a meta-algorithm that utilizes the classic physical theory as guidance to construct the candidate learning function. It shows better out-of-domain prediction accuracy compared to the classic machine learning algorithm (support vector machine). Multi-mechanism detection is built based on a cluster-weighted mixing model similar to a Gaussian mixture model. The idea is to separate the data into subsets where each subset can be modeled by a much simpler model. The case study on glass transition temperature shows that this method can provide better overall prediction accuracy even though less data is available for each subset model. In addition, the techniques developed in this work are also applied to polymer nanocomposites (PNC). PNC are new materials with outstanding dielectric properties. As a key factor in determining the dispersion state of nanoparticles in the polymer matrix

  6. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

    Science.gov (United States)

    Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin G.; Abdeldayem, Hossin A.; Smith, David D.; Witherow, William K.

    1997-01-01

    Some of the primary purposes of this work are to study important technologies, particularly involving thin films, relevant to organic and polymeric materials for improving applicability to optical circuitry and devices and to assess the contribution of convection on film quality in unit and microgravity environments. Among the most important materials processing techniques of interest in this work are solution-based and by physical vapor transport, both having proven gravitational and acceleration dependence. In particular, PolyDiAcetylenes (PDA's) and PhthaloCyanines (Pc's) are excellent NonLinear Optical (NLO) materials with the promise of significantly improved NLO properties through order and film quality enhancements possible through microgravity processing. Our approach is to focus research on integrated optical circuits and optoelectronic devices relevant to solution-based and vapor processes of interest in the Space Sciences Laboratory at the Marshall Space Flight Center (MSFC). Modification of organic materials is an important aspect of achieving more highly ordered structures in conjunction with microgravity processing. Parallel activities include characterization of materials for particular NLO properties and determination of appropriation device designs consistent with selected applications. One result of this work is the determination, theoretically, that buoyancy-driven convection occurs at low pressures in an ideal gas in a thermalgradient from source to sink. Subsequent experiment supports the theory. We have also determined theoretically that buoyancy-driven convection occurs during photodeposition of PDA, an MSFC-patented process for fabricating complex circuits, which is also supported by experiment. Finally, the discovery of intrinsic optical bistability in metal-free Pc films enables the possibility of the development of logic gate technology on the basis of these materials.

  7. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Muller, M.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2012-03-01

    Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple and optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interface(s), while protecting the cell from the environment. The durability of encapsulation materials, however, is not well established relative to the desired service life of 30 years. Therefore, we have initiated a screen test to identify the field-induced failure modes for a variety of popular PV encapsulation materials. An existing CPV module (with no PV cells present) was modified to accommodate encapsulation specimens. The module (where nominal concentration of solar flux is 500x for the domed-Fresnel design) has been mounted on a tracker in Golden, CO (elevation 1.79 km). Initial results are reported here for 18 months cumulative exposure, including the hottest and coldest months of the past year. Characteristics observed at intervals during that time include: visual appearance, direct and hemispherical transmittance, and mass. Degradation may be assessed from subsequent analysis (including yellowness index and cut-on frequency) relative to the ambient conditions present during field exposure. The fluorescence signature observed of all the silicone specimens is examined here, including possible factors of causation -- the platinum catalyst used in the addition cured materials as well as the primer used to promote adhesion to the quartz substrate and superstrate.

  8. Supersonic Particle Impacts: Cold Spray Deposition of Polymeric Material

    Science.gov (United States)

    Bush, Trenton; Schmidt, David; Rothstein, Jonathan P.

    2015-11-01

    When a solid, ductile particle impacts a substrate at sufficient velocity, the resulting heat, pressure, and plastic deformation at the interface can produce bonding. The use of a supersonic gas flow to accelerate such particles is known as Cold Spray deposition. The Cold Spray process has been commercialized for some metallic materials, but further research is required to unlock the exciting material properties possible with polymeric compounds. In this work, we present a combined computational and experimental study whose aim is to define the necessary flow conditions for a convergent-divergent de Laval nozzle to produce successful bonding in a range of polymers. From our initial exploration of temperature-pressure space, we will reveal a material dependent `window of deposition' where successful deposition is possible. Furthermore, we will present our computational work on the development of an optimized nozzle profile that maximizes particle total energy (kinetic plus thermal) upon impact and thus maximizes the likelihood of successful deposition. These predictions will be confirmed by the experimental results presented.

  9. Biocompatibility and tissue interactions of a new filler material for medical use.

    Science.gov (United States)

    Zarini, Elena; Supino, Rosanna; Pratesi, Graziella; Laccabue, Diletta; Tortoreto, Monica; Scanziani, Eugenio; Ghisleni, Gabriele; Paltrinieri, Saverio; Tunesi, Gianfranco; Nava, Maurizio

    2004-09-15

    Filler materials for medical use present limits, such as the induction of chronic inflammation and fibrosis. In the search for synthetic materials with improved biocompatible properties, a new polyacrylamide hydrogel, Aquamid (Contura SA, Montreux, Switzerland), has been investigated in preclinical systems. In cell cultures (endothelial cells and fibroblast), no or only transient biological effects were associated with 10% Aquamid exposure. The Aquamid-host interactions were examined in mice (10 mice per group) implanted subcutaneously or in the mammary fat pad with a very large volume (1.5 ml) of the material. Blood analysis, performed after 15 and 94 days (five mice per time for each group) to detect acute or late manifestations of toxicity, did not reveal relevant abnormalities in either group of Aquamid-bearing mice compared with control mice, except for a transient thrombocytopenia and a mild leukocytosis. Histological analysis of the pellet showed the presence of a thin, poorly vascularized cyst wall in implants. Only mild mesenchymal reparative and inflammatory processes were observed, even at longer observation times (more than 400 days). No alterations in any organ were detected. Despite the large volume implanted (approximately 5 percent of mouse body weight), the Aquamid pellet maintained its original size and shape without spreading or sticking to surrounding tissues. In conclusion, the study indicated a good tolerability of the new biopolymer in preclinical systems. The clinical utility of this new compound, if confirmed by clinical randomized trials showing its atoxic properties, could be in the field of aesthetic plastic surgery as a filler material for body contouring and in reconstructive surgery and above all in cancer patients to restore surgical defects. PMID:15468401

  10. Ultrashort pulse laser processing of hard tissue, dental restoration materials, and biocompatibles

    Science.gov (United States)

    Yousif, A.; Strassl, M.; Beer, F.; Verhagen, L.; Wittschier, M.; Wintner, E.

    2007-07-01

    During the last few years, ultra-short laser pulses have proven their potential for application in medical tissue treatment in many ways. In hard tissue ablation, their aptitude for material ablation with negligible collateral damage provides many advantages. Especially teeth representing an anatomically and physiologically very special region with less blood circulation and lower healing rates than other tissues require most careful treatment. Hence, overheating of the pulp and induction of microcracks are some of the most problematic issues in dental preparation. Up till now it was shown by many authors that the application of picosecond or femtosecond pulses allows to perform ablation with very low damaging potential also fitting to the physiological requirements indicated. Beside the short interaction time with the irradiated matter, scanning of the ultra-short pulse trains turned out to be crucial for ablating cavities of the required quality. One main reason for this can be seen in the fact that during scanning the time period between two subsequent pulses incident on the same spot is so much extended that no heat accumulation effects occur and each pulse can be treated as a first one with respect to its local impact. Extension of this advantageous technique to biocompatible materials, i.e. in this case dental restoration materials and titanium plasma-sprayed implants, is just a matter of consequence. Recently published results on composites fit well with earlier data on dental hard tissue. In case of plaque which has to be removed from implants, it turns out that removal of at least the calcified version is harder than tissue removal. Therefore, besides ultra-short lasers, also Diode and Neodymium lasers, in cw and pulsed modes, have been studied with respect to plaque removal and sterilization. The temperature increase during laser exposure has been experimentally evaluated in parallel.

  11. Enhanced biocompatibility and antibacterial property of polyurethane materials modified with citric acid and chitosan.

    Science.gov (United States)

    Liu, Tian-Ming; Wu, Xing-Ze; Qiu, Yun-Ren

    2016-08-01

    Citric acid (CA) and chitosan (CS) were covalently immobilized on polyurethane (PU) materials to improve the biocompatibility and antibacterial property. The polyurethane pre-polymer with isocyanate group was synthesized by one pot method, and then grafted with citric acid, followed by blending with polyethersulfone (PES) to prepare the blend membrane by phase-inversion method so that chitosan can be grafted from the membrane via esterification and acylation reactions eventually. The native and modified membranes were characterized by attenuated total reflectance-Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle measurement, and tensile strength test. Protein adsorption, platelet adhesion, hemolysis assay, activated partial thromboplastin time, prothrombin time, thrombin time, and adsorption of Ca(2+) were executed to evaluate the blood compatibility of the membranes decorated by CA and CS. Particularly, the antibacterial activities on the modified membranes were evaluated based on a vitro antibacterial test. It could be concluded that the modified membrane had good anticoagulant property and antibacterial property. PMID:27102367

  12. Synthesis, toxicity, biocompatibility, and biomedical applications of graphene and graphene-related materials

    Directory of Open Access Journals (Sweden)

    Gurunathan S

    2016-05-01

    Full Text Available Sangiliyandi Gurunathan, Jin-Hoi Kim Stem Cell and Regenerative Biology, Konkuk University, Seoul, Republic of Korea Abstract: Graphene is a two-dimensional atomic crystal, and since its development it has been applied in many novel ways in both research and industry. Graphene possesses unique properties, and it has been used in many applications including sensors, batteries, fuel cells, supercapacitors, transistors, components of high-strength machinery, and display screens in mobile devices. In the past decade, the biomedical applications of graphene have attracted much interest. Graphene has been reported to have antibacterial, antiplatelet, and anticancer activities. Several salient features of graphene make it a potential candidate for biological and biomedical applications. The synthesis, toxicity, biocompatibility, and biomedical applications of graphene are fundamental issues that require thorough investigation in any kind of applications related to human welfare. Therefore, this review addresses the various methods available for the synthesis of graphene, with special reference to biological synthesis, and highlights the biological applications of graphene with a focus on cancer therapy, drug delivery, bio-imaging, and tissue engineering, together with a brief discussion of the challenges and future perspectives of graphene. We hope to provide a comprehensive review of the latest progress in research on graphene, from synthesis to applications. Keywords: biomedical applications, cancer therapy, drug delivery, graphene, graphene-related materials, tissue engineering, toxicity 

  13. Romp as a versatile method for the obtention of differentiated polymeric materials

    OpenAIRE

    Valdemiro P. Carvalho Jr.; Camila P. Ferraz; José Luiz S. Sá; Benedito S. Lima-Neto

    2012-01-01

    Ring Opening Metathesis Polymerization (ROMP) of cyclic olefins is a powerful transition metal-catalyzed reaction for syntheses of polymers and copolymers. The key feature of this reaction is the [2+2]-cycloaddition mechanism, with retention of the olefinic unsaturation in the polymer chain and occurrence of living polymerization. With the development of metal-carbene type catalysts for this process, many addressed polymeric materials have been successfully prepared to be employed in several ...

  14. Affects of Microgravity on the Polymerization and Material Properties of Biomedical Grade Polymers

    Science.gov (United States)

    Crane, Deborah J.

    2002-01-01

    extended to include other polymers. Polymerization as well as polymer processing in a microgravity environment may affect the length and orientation of the molecular chains, the degree of crosslinking, and distribution of amorphous to crystalline portions of the material, thus changing the ultimate properties of the polymer. Small polymer samples would be produced from the resin for testing and analysis. This research would include the effect of micro-g processing by compression molded vs. ram extruded samples for analysis. Morphological alterations in the material could be monitored using Transmission Electron Microscopy and associated properties such as toughness, density and crystallinity could be determined and compared to terra produced materials using conventional mechanical testing, density gradient columns and calorimetry techniques. If alterations are evident, fatigue testing can be performed on small specimens in order to determine the material's resistance to crack initiation and propagation. number of orthopaedic implant recipients and could be extended for use in robotics and other beneficial applications. Although polymers exhibit the greatest biocompatibility, problems with debris particle generation continue to reduce the effectiveness of UHMWPE as a biomedical material. Further polymer research in a microgravity environment may prove to produce the desired alterations in the materials' morphology and associated properties, therefore providing millions of people with superior orthopaedic implant components and lessen the occurrences of repeat surgery.

  15. Nonlinear Inelastic Mechanical Behavior Of Epoxy Resin Polymeric Materials

    Science.gov (United States)

    Yekani Fard, Masoud

    compression plastic flow has negligible influence on flexural behavior in epoxy resins, which are stronger in pre-peak and post-peak softening in compression than in tension. The second model was a piecewise-linear stress strain curve simplified in the post-peak response. Beams and plates with different boundary conditions were tested and analytically studied. The flexural over-strength factor for epoxy resin polymeric materials were also evaluated.

  16. Use of computed tomography in nondestructive testing of polymeric materials

    International Nuclear Information System (INIS)

    Computed tomography has been used to detect imperfections and to measure cross-link density gradients in polymeric products, such as airplane tires, rubber shock absorbers, and filament-wound high-pressure tanks

  17. Recent Advances in Polymeric Materials Used as Electron Mediators and Immobilizing Matrices in Developing Enzyme Electrodes

    Directory of Open Access Journals (Sweden)

    Mambo Moyo

    2012-01-01

    Full Text Available Different classes of polymeric materials such as nanomaterials, sol-gel materials, conducting polymers, functional polymers and biomaterials have been used in the design of sensors and biosensors. Various methods have been used, for example from direct adsorption, covalent bonding, crossing-linking with glutaraldehyde on composites to mixing the enzymes or use of functionalized beads for the design of sensors and biosensors using these polymeric materials in recent years. It is widely acknowledged that analytical sensing at electrodes modified with polymeric materials results in low detection limits, high sensitivities, lower applied potential, good stability, efficient electron transfer and easier immobilization of enzymes on electrodes such that sensing and biosensing of environmental pollutants is made easier. However, there are a number of challenges to be addressed in order to fulfill the applications of polymeric based polymers such as cost and shortening the long laboratory synthetic pathways involved in sensor preparation. Furthermore, the toxicological effects on flora and fauna of some of these polymeric materials have not been well studied. Given these disadvantages, efforts are now geared towards introducing low cost biomaterials that can serve as alternatives for the development of novel electrochemical sensors and biosensors. This review highlights recent contributions in the development of the electrochemical sensors and biosensors based on different polymeric material. The synergistic action of some of these polymeric materials and nanocomposites imposed when combined on electrode during sensing is discussed.

  18. Evaluation of processing rate and reaction products in the polymeric material furnace using the molten slag

    International Nuclear Information System (INIS)

    A prototype furnace, which adopted the new technique for combusting the polymeric material, was manufactured. In this furnace, the polymeric materials such as rubber were fed to molten slag. The ash, generated at the surface of the polymeric material, dissolved into melt, which promoted the surface combustion of the fixed carbon. The advantages of the new furnace are: (1) High treating rate was realized at so low air excessive ratio as 0.5 ∼ 0.7. (2) The fineness of the unburned particles made the combustion in the after burner easy. (3) The reduction of flying ash coming from the gasification zone lowered the load of the ceramic filters. (author)

  19. Surface Modification of Biodegradable Polymers towards Better Biocompatibility and Lower Thrombogenicity

    OpenAIRE

    Rudolph, Andreas; Teske, Michael; Illner, Sabine; Kiefel, Volker; Sternberg, Katrin; Grabow, Niels; Wree, Andreas; Hovakimyan, Marina

    2015-01-01

    Purpose Drug-eluting stents (DES) based on permanent polymeric coating matrices have been introduced to overcome the in stent restenosis associated with bare metal stents (BMS). A further step was the development of DES with biodegradable polymeric coatings to address the risk of thrombosis associated with first-generation DES. In this study we evaluate the biocompatibility of biodegradable polymer materials for their potential use as coating matrices for DES or as materials for fully bioabso...

  20. Fine structure analysis of biocompatible ceramic materials based hydroxyapatite and metallic biomaterials 316L

    International Nuclear Information System (INIS)

    The aim of this paper was to obtain and characterize (surface morphology and fine structure) two types of materials: Ca10(PO4)6(OH)2 hydroxyapatite powder (HAp) as biocompatible ceramic materials and AISI 316L austenitic stainless steels as metallic biomaterials, which are the components of the metal–ceramic composites used for medical implants in reconstructive surgery and prosthetic treatment. The HAp was synthesized by coprecipitation method, heat treated at 200 °C, 800 °C and 1200 °C for 4 h, analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The stainless steel 316L type was made by casting, annealing and machined with a low speed (100 mm/s) in order to obtain a smooth surface and after that has been studied from residual stresses point of view in three polishing regimes conditions: at low speed polishing (150 rpm), at high speed polishing (1500 rpm) and high speed-vibration contact polishing (1500 rpm) using wide angle X-ray diffractions (WAXD). The chemical compositions of AISI 316 steel samples were measured using a Foundry Master Spectrometer equipped with CCD detector for spectral lines and the sparking spots of AISI 316L samples were analyzed using SEM. By XRD the phases of HAp powders have been identified and also the degree of crystallinity and average size of crystallites, and with SEM, we studied the morphology of the HAp. It has been found from XRD analysis that we obtained HAp with a high degree of crystallinity at 800 °C and 1200 °C, no presence of impurity and from SEM analysis we noticed the influence of heat treatment on the ceramic particles morphology. From the study of residual stress profiles of 316L samples were observed that it differs substantially for different machining regimes and from the SEM analysis of sparking spots we revealed the rough surfaces of stainless steel rods necessary for a better adhesion of HAp on it.

  1. Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Peng; Cheng, Bowen [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Tianjin Polytechnic University, Tianjin 300160 (China); Gu, Xiaohua [Qiqihar University, 30 Wenhua Road, Qiqihar 161006 (China); CAS Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080 (China); Wang, Yufei [Dalian University Technology, Dalian 116024 (China)

    2009-06-15

    Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, {sup 1}H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy. (author)

  2. Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material

    Energy Technology Data Exchange (ETDEWEB)

    Xi Peng [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Tianjin Polytechnic University, Tianjin 300160 (China); Gu Xiaohua [Qiqihar University, 30 Wenhua Road, Qiqihar 161006 (China); CAS Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080 (China)], E-mail: gxh218@yahoo.cn; Cheng Bowen [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Tianjin Polytechnic University, Tianjin 300160 (China); Wang Yufei [Dalian University Technology, Dalian 116024 (China)

    2009-06-15

    Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, {sup 1}H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy.

  3. Morphological transitions in molecular and polymeric materials: patterning, fabrication, devices

    OpenAIRE

    Calò, Annalisa

    2010-01-01

    This thesis individuates and characterizes irreversible transformations occurring in specific organic and oligomeric/polymeric thin films. These transformations are dewetting in discotic liquid crystals thin films and dewetting and smoothing in oligomeric and polyemeric films. Irreversible transformations are extensively characterized by means of optical and atomic force microscopy. In the case of discotic liquid crystals films the morphological characterization is performed sinchronically wi...

  4. Focused ion beam structuring of low melting polymeric materials

    International Nuclear Information System (INIS)

    This thesis focuses on heating effects during focused ion beam (FIB) processing of low melting polymers. The combined approach using experiments and simulations identifies the in part massive local temperatures as a convolution between intrinsic ion-matter effects and a considerable, technically-induced heating component. While the former is invariable, the latter has been minimized by an alternative process strategy which massively improves the morphological stability and minimizes chemical damage during FIB processing, thus opening new possibilities for application on sensitive, low melting materials. The study starts with systematic experimental investigations which strongly suggested the existence of a technically-induced heating component as a consequence of classically-used serpentine or raster-like patterning strategies. Based on these results, a combined simulation approach of ion trajectories and thermal spike model calculations have been employed to get a deeper insight into spatial and temporal temperature evolution. The results were then combined with the thermodynamic behavior of polymers by means of melting and volatizing temperatures. The comparison of these simulationbased predictions with real FIB experiments revealed very good agreement, proving the applicability of the approach used to describe the temperature evolution from a fundamental point of view. As a next step, these simulations were then applied to the dierent scanning strategies which further con rmed the existence of a technically-induced heating component via classically-used patterning approaches. Due to the deep insight gained via simulations, an alternative patterning strategy was developed, which was expected to minimize these avoidable influences. This new strategy was then evaluated using a multi-technique approach, which revealed strongly reduced chemical damage together with increasing morphological stabilities even for temperature-sensitive polymers. Finally, this alternative

  5. Methods for probing charging properties of polymeric materials using XPS

    International Nuclear Information System (INIS)

    Various thin polystyrene, PS, and poly(methyl methacrylate), PMMA and PS + PMMA blend films have been examined using the technique of recording X-ray photoelectron spectrum while the sample is subjected to ±10 V d.c. bias, and three different forms of (square-wave (SQW), sinusoidal (SIN) and triangular (TRG)), a.c. pulses. All films exhibit charging shifts as observed in the position of the corresponding C1s peak under d.c. bias. The a.c. pulses convert the single C1s peak to twinned peaks in the case of the square-wave form, and distort severely in the cases of the SIN, and TRG forms, and all three of them exhibit strong frequency dependence. In order to mimic and better understand the behavior of these polymeric materials, an artificial dielectric system consisting of a clean Si-wafer coupled to an external 1 MΩ resistor and 56 nF capacitor is created, and its response to different forms of voltage stimuli, is examined in detail. A simple electrical circuit model is also developed treating the system as consisting of a parallel resistor and a series capacitor. With the help of the model, the response of the artificial system is successfully calculated as judged by comparison with the experimental data. Using one high frequency SQW measurements, the off-set in the charging shift due to the extra low-energy neutralizing electrons is estimated. After correcting the corresponding off-set shifts, the XPS spectra of the three different PS films, one PMMA, and one PS + PMMA blend film are re-examined. As a result of these detailed analysis, there emerges a clear relationship between the thicknesses of the PS films with their charging abilities. In the blend film, PS and PMMA domains are electrically separated, and exhibit different charging shifts, however, the presence of one is felt by the other. Hence, the PS component shifts are larger in the blend, due to the presence of PMMA domains, which has intrinsically a larger Reff, and conversely the PMMA component shifts

  6. Methods for probing charging properties of polymeric materials using XPS

    Energy Technology Data Exchange (ETDEWEB)

    Sezen, Hikmet; Ertas, Gulay [Department of Chemistry, and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Suzer, Sefik, E-mail: suzer@fen.bilkent.edu.t [Department of Chemistry, and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

    2010-05-15

    Various thin polystyrene, PS, and poly(methyl methacrylate), PMMA and PS + PMMA blend films have been examined using the technique of recording X-ray photoelectron spectrum while the sample is subjected to +-10 V d.c. bias, and three different forms of (square-wave (SQW), sinusoidal (SIN) and triangular (TRG)), a.c. pulses. All films exhibit charging shifts as observed in the position of the corresponding C1s peak under d.c. bias. The a.c. pulses convert the single C1s peak to twinned peaks in the case of the square-wave form, and distort severely in the cases of the SIN, and TRG forms, and all three of them exhibit strong frequency dependence. In order to mimic and better understand the behavior of these polymeric materials, an artificial dielectric system consisting of a clean Si-wafer coupled to an external 1 MOMEGA resistor and 56 nF capacitor is created, and its response to different forms of voltage stimuli, is examined in detail. A simple electrical circuit model is also developed treating the system as consisting of a parallel resistor and a series capacitor. With the help of the model, the response of the artificial system is successfully calculated as judged by comparison with the experimental data. Using one high frequency SQW measurements, the off-set in the charging shift due to the extra low-energy neutralizing electrons is estimated. After correcting the corresponding off-set shifts, the XPS spectra of the three different PS films, one PMMA, and one PS + PMMA blend film are re-examined. As a result of these detailed analysis, there emerges a clear relationship between the thicknesses of the PS films with their charging abilities. In the blend film, PS and PMMA domains are electrically separated, and exhibit different charging shifts, however, the presence of one is felt by the other. Hence, the PS component shifts are larger in the blend, due to the presence of PMMA domains, which has intrinsically a larger R{sub eff}, and conversely the PMMA

  7. In vitro biocompatibility evaluation of ePTFE graft with controlled release of heparin from mesoporous material

    Energy Technology Data Exchange (ETDEWEB)

    Li Kun [Department of Vascular Surgery, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008 (China); Zhou Yu; Yang Jia yuan; Zhu Jianhua [Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Liu Changjian, E-mail: cjliu1331@gmail.com [Department of Vascular Surgery, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008 (China)

    2012-02-01

    Heparin-loaded mesoporous-expanded poly(tetrafluoroethylene) (ePTFE) vascular prosthesis (HMVP-n) are prepared and the biocompatibility is studied by contact angle, heparin release, platelet resistance, chromogenic assay, endothelial progenitor cells (EPCs) proliferation and produced-NO function, in order to illustrate the relationship between the performance of artificial vessels and their mesostructure. Through in situ synthesis of mesoporous silica on ePTFE grafts, different mesoporous silica materials can be uniformly coated on the surface as well as the internal fibers of the artificial vessels to give various mesoporous vascular prosthesis, named as MVP-n. Structure analysis through scanning electron microscopy (SEM), energy dispersive X-ray detector (EDX) analysis and nitrogen sorption experiment indicates that different MVP-n series own the similar n{sub F}/n{sub Si} ratio of both surface and cross-section, large Brunauer-Emmett-Tellerand (BET) surface area and average pore size located in meso range but different textural properties. Owning to the existence of mesostucture, controlled release and high bioactivity of heparin can be achieved, and the biocompatibility greatly enhance: surface hydrophilicity increases; no adherent platelet was observed on the surface of HMVP-n when they contacted with platelet-enriched plasma; endothelial progenitor cells proliferous potential and produced-NO function exhibit better endothelial coverage of grafts. And the performance is closely related to the mesostructure, suggesting a new way to improve the biocompatibility of biomaterials through controlling their mesostructure.

  8. In vitro biocompatibility evaluation of ePTFE graft with controlled release of heparin from mesoporous material

    International Nuclear Information System (INIS)

    Heparin-loaded mesoporous-expanded poly(tetrafluoroethylene) (ePTFE) vascular prosthesis (HMVP-n) are prepared and the biocompatibility is studied by contact angle, heparin release, platelet resistance, chromogenic assay, endothelial progenitor cells (EPCs) proliferation and produced-NO function, in order to illustrate the relationship between the performance of artificial vessels and their mesostructure. Through in situ synthesis of mesoporous silica on ePTFE grafts, different mesoporous silica materials can be uniformly coated on the surface as well as the internal fibers of the artificial vessels to give various mesoporous vascular prosthesis, named as MVP-n. Structure analysis through scanning electron microscopy (SEM), energy dispersive X-ray detector (EDX) analysis and nitrogen sorption experiment indicates that different MVP-n series own the similar nF/nSi ratio of both surface and cross-section, large Brunauer-Emmett-Tellerand (BET) surface area and average pore size located in meso range but different textural properties. Owning to the existence of mesostucture, controlled release and high bioactivity of heparin can be achieved, and the biocompatibility greatly enhance: surface hydrophilicity increases; no adherent platelet was observed on the surface of HMVP-n when they contacted with platelet-enriched plasma; endothelial progenitor cells proliferous potential and produced-NO function exhibit better endothelial coverage of grafts. And the performance is closely related to the mesostructure, suggesting a new way to improve the biocompatibility of biomaterials through controlling their mesostructure.

  9. In vitro biocompatibility evaluation of ePTFE graft with controlled release of heparin from mesoporous material

    Science.gov (United States)

    Li, Kun; Zhou, Yu; Yang, Jia yuan; Zhu, Jian hua; Liu, Chang jian

    2012-02-01

    Heparin-loaded mesoporous-expanded poly(tetrafluoroethylene) (ePTFE) vascular prosthesis (HMVP-n) are prepared and the biocompatibility is studied by contact angle, heparin release, platelet resistance, chromogenic assay, endothelial progenitor cells (EPCs) proliferation and produced-NO function, in order to illustrate the relationship between the performance of artificial vessels and their mesostructure. Through in situ synthesis of mesoporous silica on ePTFE grafts, different mesoporous silica materials can be uniformly coated on the surface as well as the internal fibers of the artificial vessels to give various mesoporous vascular prosthesis, named as MVP-n. Structure analysis through scanning electron microscopy (SEM), energy dispersive X-ray detector (EDX) analysis and nitrogen sorption experiment indicates that different MVP-n series own the similar nF/nSi ratio of both surface and cross-section, large Brunauer-Emmett-Tellerand (BET) surface area and average pore size located in meso range but different textural properties. Owning to the existence of mesostucture, controlled release and high bioactivity of heparin can be achieved, and the biocompatibility greatly enhance: surface hydrophilicity increases; no adherent platelet was observed on the surface of HMVP-n when they contacted with platelet-enriched plasma; endothelial progenitor cells proliferous potential and produced-NO function exhibit better endothelial coverage of grafts. And the performance is closely related to the mesostructure, suggesting a new way to improve the biocompatibility of biomaterials through controlling their mesostructure.

  10. Development of a impact limiter for radioactive material transport packages - characterization of the polymeric material used

    International Nuclear Information System (INIS)

    Impact limiters are sacrificial components widely used to protect radioactive waste packages against damages arising from falls, fires and collisions with protruding objects. Several materials have been used as impact limiter filling: wood, aluminum honeycomb, and metallic or polymeric foams. Besides, hollow structures are also used as shock absorbers, either as a single shell or as a tube array. One of the most popular materials among package designers is rigid polyurethane foam, owing to its toughness, workability, low specific weight, low costs and commercial availability. In Brazil, a foam developed using the polymer extracted from the castor oil plant (Ricinus communis) is being studied as a potential impact limiter filling. For a better performance of this material, it is necessary to minimize the impact limiter dimensions without compromising the package safety. For this, a detailed knowledge of the foam physical and mechanical properties is essential. A relatively vast amount of data about regular polymeric foams can be found in the literature and in foreign manufacturers brochures, but no data has been published about the properties of the castor oil foam. This paper presents data gathered in an ongoing research program aiming at the development of a Type-B packaging. Foam samples were submitted to uniaxial static compression tests and to hydrostatic tests. The results obtained reveal that the castor oil foam has a mechanical behavior similar to that of regular foams, with good property reproducibility and homogeneity. (author)

  11. Biocompatibility and characterisation of a candidate microelectrode material for biosensor applications

    CERN Document Server

    Cyster, L A

    2001-01-01

    TiN films. Results demonstrated how the deposition parameters could influence the crystallographic nature of TiN films. The 0.2 and 1.0 mu m Type I TiN and both Type II TiN films were selected to allow comparison oj the influence of surface chemistry versus topography on the biocompatibility of TiN films. Biocompatibility testing using 3T3-L1 fibroblasts and C6 Glial cells showed that at early time points TiN films with increased surface interstitial nitrogen content were more favourable for the attachment of increased numbers of cells. At later time points increased cell spreading was observed on the Type II TiN films indicating that increased grain size and topographical features resulted in increased cell spreading. Investigation of the biocompatibility of the 0.2 and 1.0 mu m Type I TiN films and both Type II TiN films with primary hippocampal neurones showed that surface chemistry with predominantly interstitial nitrogen resulted in neuronal network formation similar to the control substrate. Increased n...

  12. Material properties and in vitro biocompatibility of a newly developed bone cement

    Directory of Open Access Journals (Sweden)

    Elke Mitzner

    2009-01-01

    Full Text Available In this study mechanical properties and biocompatibility (In Vitro of a new bone cement were investigated. A new platform technology named COOL is a variable composite of dissolved, chemically modified PMMA and different bioceramics. COOL cures at body temperature via a classical cementation reaction. Compressive strengths ranging from 3.6 ± 0.8 to 62.8 ± 1.3 MPa and bending strengths ranging from 9.9 ± 2.4 to 26.4 ± 3.0 MPa were achieved with different COOL formulations. Porosity varied between 31 and 43%. Varying the components of each formulation mechanical properties and porosity could be adjusted. In Vitro biocompatibility studies with primary human osteoblasts (pHOB in direct contact with different COOL formulations, did not reveal any signs of toxicity. In contrast to Refobacin® R, cells incubated with COOL showed similar density, viability and ALP activity compared to control, if specimen were added immediately to the cell monolayer after preparation. In conclusion, COOL has promising mechanical properties in combination with high biocompatibility In Vitro and combines different advantages of both CPCs and PMMA cements by avoiding some of the respective shortcomings.

  13. Numerical study of the thermal degradation of isotropic and anisotropic polymeric materials

    Energy Technology Data Exchange (ETDEWEB)

    Soler, E. [Departamento de Lenguajes y Ciencias de la Computacion, ETSI Informatica, Universidad de Malaga, 29071 Malaga (Spain); Ramos, J.I. [Room I-320-D, ETS Ingenieros Industriales, Universidad de Malaga, Plaza El Ejido, s/n, 29013 Malaga (Spain)

    2005-08-01

    The thermal degradation of two-dimensional isotropic, orthotropic and anisotropic polymeric materials is studied numerically by means of a second-order accurate (in both space and time) linearly implicit finite difference formulation which results in linear algebraic equations at each time step. It is shown that, for both isotropic and orthotropic composites, the monomer mass diffusion tensor plays a role in initiating the polymerization kinetics, the formation of a polymerization kernel and the initial front propagation, whereas the later stages of the polymerization are nearly independent of the monomer mass diffusion tensor. In anisotropic polymeric composites, it has been found that the monomer mass diffusion tensor plays a paramount role in determining the initial stages of the polymerization and the subsequent propagation of the polymerization front, the direction and speed of propagation of which are found to be related to the principal directions of both the monomer mass and the heat diffusion tensors. It is also shown that the polymerization time and temperatures depend strongly on the anisotropy of the mass and heat diffusion tensors. (authors)

  14. New Photocrosslinking Polymeric Materials for Liquid Crystal Photoalignment

    OpenAIRE

    Mahilny, Uladzimir; Trofimova, Alexandra; Stankevich, Alexander; Tolstik, Alexei; Murauski, Anatoli; Muravsky, Alexander

    2013-01-01

    The photoinduced alignment (photoalignment) of nematic liquid crystals (LC) is of great interest as a contactless technique to create patterned LC aligning layers which have good prospect as basic elements of nonlinear optical devices like controllable waveguide structures with discrete diffraction, statical and dynamical photonic media etc. LC photoalignment on the surface of benzaldehyde polymeric layer caused by photochemical reaction of benzaldehyde side groups is investigated exper...

  15. Optimization of microencapsulation process for self-healing polymeric material

    OpenAIRE

    Then, S; Neon, G. S.; Abu Kasim, N. H.

    2011-01-01

    A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was successfully prepared by in situ polymerization. The effect of diverse process parameters and ingredients on the morphology of the microcapsules was observed by SEM, optical microscopy (OM) and digital microscopy. Different techniques for the characterization of the chemical structure and the core content were considered such as FT-IR and (1)H-NMR as well as the characterization of thermal propert...

  16. Policaprolactone/polyvinylpyrrolidone/siloxane hybrid materials: Synthesis and in vitro delivery of diclofenac and biocompatibility with periodontal ligament fibroblasts.

    Science.gov (United States)

    Peña, José A; Gutiérrez, Sandra J; Villamil, Jean C; Agudelo, Natalia A; Pérez, León D

    2016-01-01

    In this paper, we report the synthesis of polycaprolactone (PCL) based hybrid materials containing hydrophilic domains composed of N-vinylpyrrolidone (VP), and γ-methacryloxypropyltrimethoxysilane (MPS). The hybrid materials were obtained by RAFT copolymerization of N-vinylpyrrolidone and MPS using a pre-formed dixanthate-end-functionalized PCL as macro-chain transfer agent, followed by a post-reaction crosslinking step. The composition of the samples was determined by elemental and thermogravimetric analyses. Differential scanning calorimetry and X-ray diffraction indicated that the crystallinity of PCL decreases in the presence of the hydrophilic domains. Scanning electron microscopy images revealed that the samples present an interconnected porous structure on the swelling. Compared to PCL, the hybrid materials presented low water contact angle values and higher elastic modulus. These materials showed controlled release of diclofenac, and biocompatibility with human periodontal ligament fibroblasts. PMID:26478287

  17. Micromechanical exfoliation of two-dimensional materials by a polymeric stamp

    Science.gov (United States)

    Ferraz da Costa, M. C.; Ribeiro, H. B.; Kessler, F.; de Souza, E. A. T.; Fechine, G. J. M.

    2016-02-01

    In this work, an alternative technique to the traditional micromechanical exfoliation of two-dimensional materials is proposed, consisting of isolated flakes of graphite and molybdenum disulphide onto polymeric surfaces films. The set made up of polymer and flakes is fabricated by using a hot-press machine called polymeric stamp. The polymeric stamp was used to allocate flakes and also to allow the exfoliation process to take place just in one face of isolated flake. Optical microscopy, Raman spectroscopy and photoluminescence spectroscopy results showed that multilayers, bilayers and single layers of graphene and MoS2 were obtained by using a polymeric stamp as tool for micromechanical exfoliation. These crystals were more easily found because the exfoliation process concentrates them in well-defined locations. The results prove the effectiveness of the method by embedding two-dimensional materials into polymers to fabricate fewer layers crystals in a fast, economic and clean way.

  18. Material properties and in vitro biocompatibility of a newly developed bone cement

    OpenAIRE

    Elke Mitzner; Paco Albertus Hubert Maria Pelt; Christian Mueller; Angela Strohwig; Wolf-Dieter Mueller

    2009-01-01

    In this study mechanical properties and biocompatibility (In Vitro) of a new bone cement were investigated. A new platform technology named COOL is a variable composite of dissolved, chemically modified PMMA and different bioceramics. COOL cures at body temperature via a classical cementation reaction. Compressive strengths ranging from 3.6 ± 0.8 to 62.8 ± 1.3 MPa and bending strengths ranging from 9.9 ± 2.4 to 26.4 ± 3.0 MPa were achieved with different COOL formulations. Porosity varied bet...

  19. Carbon-Coated Gold Nanorods: A Facile Route to Biocompatible Materials for Photothermal Applications.

    Science.gov (United States)

    Kaneti, Yusuf Valentino; Chen, Chuyang; Liu, Minsu; Wang, Xiaochun; Yang, Jia Lin; Taylor, Robert Allen; Jiang, Xuchuan; Yu, Aibing

    2015-11-25

    Gold nanorods and their core-shell nanocomposites have been widely studied because of their well-defined anisotropy and unique optical properties and applications. This study demonstrates a facile hydrothermal synthesis strategy for generating carbon coating on gold nanorods (AuNRs@C) under mild conditions (glucose). The structure and composition of the produced core-shell nanocomposites were characterized using advanced microscopic and spectroscopic techniques. The functional properties, particularly the photothermal and biocompatibility properties of the produced AuNRs@C, were quantified to assess their potential in photothermal hyperthermia. These AuNRs@C were tested in vitro (under representative treatment conditions) using near-infrared (NIR) light irradiation. It was found that the AuNRs produced here exhibit exemplary heat generation capability. Temperature changes of 10.5, 9, and 8 °C for AuNRs@C were observed with carbon shell thicknesses of 10, 17, and 25 nm, respectively, at a concentration of 50 μM, after 600 s of irradiation with a laser power of 0.17 W/cm(2). In addition, the synthesized AuNRs@C also exhibit good biocompatibility toward two soft tissue sarcoma cell lines (HT1080, a fibrosarcoma; and GCT, a fibrous histiocytoma). The cell viability study shows that AuNRs@C (at a concentration of <0.1 mg/mL) core-shell particles induce significantly lower cytotoxicity on both HT1080 and GCT cell lines, as compared with cetyltrimethylammonium bromide (CTAB)-capped AuNRs. Furthermore, similar to PEG-modified AuNRs, they are also safe to both HT1080 and GCT cell lines. This biocompatibility results from a surface full of -OH or -COH groups, which are suitable for linking and are nontoxic Therefore, the AuNRs@C represent a viable alternative to PEG-coated AuNRs for facile synthesis and improved photothermal conversion. Overall, these findings open up a new class of carbon-coated nanostructures that are biocompatible and could potentially be employed in a

  20. New Soft Polymeric Materials Applicable as Elastomeric Transducers

    DEFF Research Database (Denmark)

    Bejenariu, Anca Gabriela; Skov, Anne Ladegaard

    range of temperature10-13. However, silicone elastomer has weak intermolecular forces among polymeric chains, which limits its mechanical strength. Mechanical properties may be improved using different methods (adding fillers14, interpenetrating network synthesis15 or bimodal network synthesis16). In...... ideal springs. The viscoelastic behavior as function of the applied frequency (LVE diagram) is shown for different hyperswollen networks with varying stoichiometric imbalance (r). The results are compared with results of similar un-swollen networks. The hyperswollen networks are significantly softer and...

  1. Biocompatibility testing of novel starch-based materials with potential application in orthopaedic surgery: a preliminary study.

    Science.gov (United States)

    Mendes, S C; Reis, R L; Bovell, Y P; Cunha, A M; van Blitterswijk, C A; de Bruijn, J D

    2001-07-01

    This paper describes an extensive biocompatibility evaluation of biodegradable starch-based materials aimed at orthopaedic applications as temporary bone replacement/fixation implants. For that purpose, a polymer (starch/ethylene vinyl alcohol blend, SEVA-C) and a composite of SEVA-C reinforced with hydroxyapatite (HA) particles, were evaluated in both in vitro and in vivo assays. For the in vitro analysis cell culture methods were used. The in vivo tissue reactions were evaluated in an intramuscular and intracortical bone implantation model on goats, using light and scanning electron microscopy. A computerized image analysis system was used to obtain histomorphometric data regarding bone contact and remodelling after 6 and 12 weeks of implantation. In both in vitro and in vivo models, the SEVA-C-based materials did not induce adverse reactions, which in addition to their bone-matching mechanical properties makes them promising materials for bone replacement fixation. PMID:11426886

  2. Functional Materials from Nanostructured Block Polymers Prepared via Ring-opening Metathesis Polymerization

    Science.gov (United States)

    Pitet, Louis Marcel

    The structural and molecular versatility afforded to polymeric materials by ruthenium catalysts during ring-opening metathesis polymerization (ROMP) cannot be exaggerated. This dissertation describes the synthesis of functionalized polyolefins via ROMP with particular emphasis on designing straightforward approaches to materials in which the molecular structure is meticulously controlled. Moreover, large portions of the body are dedicated to describing functionalized polyolefins as precursors to more complex multicomponent block copolymers. Block copolymers having various components derived from mechanistically incompatible feedstocks were designed with translational targets in mind, including toughening agents for brittle plastics, and free-standing nanoporous membranes. Several fundamental structure-property relationships were also explored for the newly synthesized materials.

  3. Impact of Chlorine dioxide Gas on the Barrier Properties of Polymeric Packaging Materials

    Science.gov (United States)

    One important criterion of polymeric material selection and packaging design for fresh produce is choosing the material with suitable ratio of carbon dioxide and oxygen permabilities (PCO2/P O2), to the respiratory proportion of the targeted produce. The ratio of [O2] and [CO2] in the head space var...

  4. Durability of polymeric materials in space : Application of scanning thermal microscopy

    NARCIS (Netherlands)

    Fischer, H.R.; Semprimoschnig, C.O.A.

    2009-01-01

    In this work, a new method, the scanning thermal microscopy method, is applied to study the durability of polymeric materials for space applications. The method was applied to study ground-tested as well as space-retrieved materials. Space-grade silicones, high-temperature polyimides, and the well-k

  5. Preparation and use of polymeric materials containing hydrophobic anions and plasticizers for separation of cesium and strontium

    International Nuclear Information System (INIS)

    Preparation and use is described for polymeric materials containing hydrophobic anions and plasticizers for extraction of cesium and strontium. The use of polymeric materials containing plasticizers which are solvents for hydrophobic anions such as derivatives of cobalt dicarbollide or tetraphenylborate which are capable of extracting cesium and strontium ions from aqueous solutions in contact with the polymeric materials, is described. The polymeric material may also include a synergistic agent for a given ion like polyethylene glycol or a crown ether, for removal of radioactive isotopes of cesium and strontium from solutions of diverse composition and, in particular, for solutions containing large excess of sodium nitrate

  6. Polymerization of cardanol using soybean peroxidase and its potential application as anti-biofilm coating material.

    Science.gov (United States)

    Kim, Yong Hwan; An, Eun Suk; Song, Bong Keun; Kim, Dong Shik; Chelikani, Rahul

    2003-09-01

    Soybean peroxidase (20 mg) catalyzed the oxidative polymerization of cardanol in 2-propanol/phospate buffer solution (25 ml, 1:1 v/v) and yielded 62% polycardanol over 6 h. Cobalt naphthenate (0.5% w/w) catalyzed the crosslinking of polycardanol and the final hardness of crosslinked polycardanol film exceeded 9 H scale as pencil scratch hardness, which shows a high potential as a commercial coating material. In addition, it showed an excellent anti-biofouling activity to Pseudomonas fluorescens compared to other polymeric materials such as polypropylene. PMID:14571976

  7. Design considerations for multi component molecular-polymeric nonlinear optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Singer, K.D. (Case Western Reserve Univ., Cleveland, OH (USA). Dept. of Physics); Kuzyk, M.G. (Washington State Univ., Pullman, WA (USA). Dept. of Physics); Fang, T.; Holland, W.R. (AT and T Bell Labs., Princeton, NJ (USA)); Cahill, P.A. (Sandia National Labs., Albuquerque, NM (USA))

    1990-01-01

    We review our work on multi component polymeric nonlinear optical materials. These materials consist of nonlinear optical molecules incorporated in a polymeric host. A cross-linked triazine polymer incorporating a dicyanovinyl terminated azo dye was found to be relatively stable at 85{degree} and posses an electro-optic coefficient of 11pm/V. We have also observed the zero dispersion condition in a new anomalous dispersion dye for phase matched second harmonic generation, and expect efficient conversion to the blue. A squarylium dye, ISQ, has been found to posses a large third order nonlinearity, and may display two-level behavior. 24 refs., 11 figs.

  8. Polymeric Materials Review on Oxidation, Stabilization and Evaluation using CL and DSC Methods

    CERN Document Server

    Ilie, Sorin; CERN. Geneva. TE Department

    2009-01-01

    Within TE - VSC Group, the Chemistry Laboratory actually works on the project entitled “Studies of Radiation Induced Aging Effects in Polymeric Cable Insulators”. The aim of the project is the characterization and the evaluation of the aging effects mainly induced by ionizing radiations on the various polymeric materials in cables structure. It is expected, using the accumulated data, to foresee the life-time of these materials in the specific CERN accelerator systems and, also, to assure an acceptance quality control of the supplied cables in CERN.

  9. Romp as a versatile method for the obtention of differentiated polymeric materials

    Directory of Open Access Journals (Sweden)

    Valdemiro P. Carvalho Jr.

    2012-01-01

    Full Text Available Ring Opening Metathesis Polymerization (ROMP of cyclic olefins is a powerful transition metal-catalyzed reaction for syntheses of polymers and copolymers. The key feature of this reaction is the [2+2]-cycloaddition mechanism, with retention of the olefinic unsaturation in the polymer chain and occurrence of living polymerization. With the development of metal-carbene type catalysts for this process, many addressed polymeric materials have been successfully prepared to be employed in several fields of the science and technology. This review summarizes recent examples of syntheses of polymers with amphiphilic features such as block, graft, brush or star copolymers; as well syntheses of biomaterials, dendronized architectures, photoactive polymers, cross-linked or self-healing materials, and polymers from renewed supplies.

  10. Handbook - Status assessment of polymeric materials in flue gas cleaning systems; Handbok - Statusbedoemning av polymera material i roekgassystem

    Energy Technology Data Exchange (ETDEWEB)

    Roemhild, Stefanie

    2011-01-15

    In today's flue gas cleaning systems with advanced energy recovery systems and improved flue gas cleaning, the use of polymeric materials has continuously increased in applications where the flue gas environment is to corrosive to be handled with metallic materials. Typical polymeric materials used are fibre reinforced plastics (FRP), glassflake-filled linings, polypropylene (PP) and fluoropolymers. Demands on increased profitability and efficiency at incineration plants involve that also polymeric materials have to face more demanding environments with increased temperature, temperature changes, changes in fuel composition and therewith fluegas composition and longer service intervals. The knowledge on how polymeric materials perform in general and how these service conditions influence them, is, however, poor and continuous status assessment is therefore necessary. The overall aim of this project has been to assess simple techniques for status assessment of polymeric materials in flue gas cleaning equipment and to perform an inventory of present experience and knowledge on the use of polymeric materials. The project consisted of an inventory of present experience, analysis of material from shut-down plants and plants still in service, field testing in a plant adding sulphur during combustion and the assessment of different non-destructive testing (NDT) methods by laboratory experiments. The results of the project are summarised in the form of a handbook which in the first place addresses plant owners and maintenance staff at incineration plants and within the pulp and paper industry. In the introductory chapter typical polymeric materials (FRP, flake linings, PP and fluoropolymers) used in flue gas cleaning equipment are described as well as the occurring corrosion mechanisms. The inventory of process equipment is divided into sections about scrubbers, flue gas ducts, stacks, internals and other equipment such as storage tanks. Typical damages are

  11. Synthesis, toxicity, biocompatibility, and biomedical applications of graphene and graphene-related materials

    Science.gov (United States)

    Gurunathan, Sangiliyandi; Kim, Jin-Hoi

    2016-01-01

    Graphene is a two-dimensional atomic crystal, and since its development it has been applied in many novel ways in both research and industry. Graphene possesses unique properties, and it has been used in many applications including sensors, batteries, fuel cells, supercapacitors, transistors, components of high-strength machinery, and display screens in mobile devices. In the past decade, the biomedical applications of graphene have attracted much interest. Graphene has been reported to have antibacterial, antiplatelet, and anticancer activities. Several salient features of graphene make it a potential candidate for biological and biomedical applications. The synthesis, toxicity, biocompatibility, and biomedical applications of graphene are fundamental issues that require thorough investigation in any kind of applications related to human welfare. Therefore, this review addresses the various methods available for the synthesis of graphene, with special reference to biological synthesis, and highlights the biological applications of graphene with a focus on cancer therapy, drug delivery, bio-imaging, and tissue engineering, together with a brief discussion of the challenges and future perspectives of graphene. We hope to provide a comprehensive review of the latest progress in research on graphene, from synthesis to applications.

  12. Surface engineering of stainless steel materials by covalent collagen immobilization to improve implant biocompatibility.

    Science.gov (United States)

    Müller, Rainer; Abke, Jochen; Schnell, Edith; Macionczyk, Frank; Gbureck, Uwe; Mehrl, Robert; Ruszczak, Zbigniev; Kujat, Richard; Englert, Carsten; Nerlich, Michael; Angele, Peter

    2005-12-01

    It was shown recently that the deposition of thin films of tantalum and tantalum oxide enhanced the long-term biocompatibility of stainless steel biomaterials due to an increase in their corrosion resistance. In this study, we used this tantalum oxide coating as a basis for covalent immobilization of a collagen layer, which should result in a further improvement of implant tissue integration. Because of the high degradation rate of natural collagen in vivo, covalent immobilization as well as carbodiimide induced cross-linking of the protein was performed. It was found that the combination of the silane-coupling agent aminopropyl triethoxysilane and the linker molecule N,N'-disulphosuccinimidyl suberate was a very effective system for collagen immobilizing. Mechanical and enzymatic stability testing revealed a higher stability of covalent bound collagen layers compared to physically adsorbed collagen layers. The biological response induced by the surface modifications was evaluated by in vitro cell culture with human mesenchymal stem cells as well as by in vivo subcutaneous implantation into nude mice. The presence of collagen clearly improved the cytocompatibility of the stainless steel implants which, nevertheless, significantly depended on the cross-linking degree of the collagen layer. PMID:15967497

  13. Mass Transfer Study of Chlorine Dioxide Gas Through Polymeric Packaging Materials

    Science.gov (United States)

    A continuous system for measuring the mass transfer of gaseous chlorine dioxide (ClO2), a strong oxidizing agent and used in food and pharmaceutical packaging, through 10 different types of polymeric packaging material was developed utilizing electrochemical sensor as a detector. Permeability, diff...

  14. INTERACTION CURVES OF LINEARLY INTENSIFYING POLYMERIC MATERIALS UNDER TENSILE-TORSIONAL STRESS

    Institute of Scientific and Technical Information of China (English)

    Mao-sheng Zhan

    2000-01-01

    Theoretical and experimental research has been performed on the interaction curves and stress paths of crystalline polymeric materials PE and POM under tensile-torsional stress with a linearly intensifying model and in terms of the yield points undergoing Von Mises criterion.

  15. Studies on Development of Polymeric Materials Using Gamma Irradiation for Contact and Intraocular Lenses

    International Nuclear Information System (INIS)

    For the development of materials for contact lenses and intraocular lenses, the selection criteria is based on the (i) capacity to absorb and retain water, (ii) hydrophilicity and hydrophobicity, (iii) refractive index and (IV) hardness besides the other essential properties. Various monomers are being studied to develop suitable materials for such applications. Selection of suitable monomers that can be converted into optical materials of desired characteristics is the most essential step. In the present paper, an attempt has been made to develop suitable optical polymers based on 2-hydroxy ethyl methacrylate (HEMA), N-vinyl pyrrolidone (NVP), methyl methacrylate (MMA), methacrylic acid (MAA), and styrene. Compositions were prepared in such a way that polymers of varying hydrophilicity or hydrophobicity could be obtained keeping HEMA as the base (main) monomer. For polymerization, gamma irradiation (Co-60 as a source) was used. The results of the study showed that: (i) an increase in NVP and MAA content brought in an increase in hydrophilicity of polymerized HEMA (pHEMA), while the addition of styrene and MMA decreased hydrophilicity of polymerized HEMA (pHEMA), (II) polymers for contact lenses with water retention capacity as high as >50 wt.% and as low as <10 wt % with varying content of suitable comonomers can be designed, (III) polymeric materials for contact lenses can be made by using radiation processing such as Co-60 and (IV) a dose of 40 kGy was found to be ideal for purpose.

  16. Studies on Development of Polymeric Materials Using Gamma Irradiation for Contact and Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    R. K. Khandal

    2009-01-01

    Full Text Available For the development of materials for contact lenses and intraocular lenses, the selection criteria is based on the (i capacity to absorb and retain water, (ii hydrophilicity and hydrophobicity, (iii refractive index and (iv hardness besides the other essential properties. Various monomers are being studied to develop suitable materials for such applications. Selection of suitable monomers that can be converted into optical materials of desired characteristics is the most essential step. In the present paper, an attempt has been made to develop suitable optical polymers based on 2-hydroxy ethyl methacrylate (HEMA, N-vinyl pyrrolidone (NVP, methyl methacrylate (MMA, methacrylic acid (MAA, and styrene. Compositions were prepared in such a way that polymers of varying hydrophilicity or hydrophobicity could be obtained keeping HEMA as the base (main monomer. For polymerization, gamma irradiation (Co-60 as a source was used. The results of the study showed that: (i an increase in NVP and MAA content brought in an increase in hydrophilicity of polymerized HEMA (pHEMA, while the addition of styrene and MMA decreased hydrophilicity of polymerized HEMA (pHEMA, (ii polymers for contact lenses with water retention capacity as high as >50 wt.% and as low as <10 wt% with varying content of suitable comonomers can be designed, (iii polymeric materials for contact lenses can be made by using radiation processing such as Co-60 and (iv a dose of 40 kGy was found to be ideal for purpose.

  17. Chosen manufacture methods of Polymeric Graded Materials with electrical and magnetic properties gradation

    Directory of Open Access Journals (Sweden)

    J. Stabik

    2012-10-01

    Full Text Available Purpose: The purpose of the paper is to present main results of Polymeric Graded Materials (PGMs investigations realized in Silesian University of Technology, Division of Metallic and Polymeric Materials Processing. Methods of PGMs manufacture with electrical and magnetic properties gradation are mainly discussed.Design/methodology/approach: In short introduction general remarks on functionally graded materials (FGMs and PGMs are presented. Next, methods used to prepare PGMs are presented together with physical basics determining composition, structure and properties gradation. Research methodology and chosen results showing PGMs structure and properties are also presented.Findings: Achieved results show that it is possible do design graded material structure and composition and to manufacture PGM that not precisely but in high extend meets designed requirements. The basic condition to accomplish this task is that physical basics of structure and composition gradient formation are known and relations between technological process parameters and ready material characteristics are properly applied.Research limitations/implications: Only chosen methods of PGMs manufacture are presented and only chosen PGMs characteristics are discussed.Practical implications: Presented technologies are widely used in industry to processing polymeric materials. Defined changes in parameters and properly designed composition will allow to utilize these technologies to PGMs manufacture. Ready parts with properties gradation may be applied in almost all industry branches. Few possible applications are presented in the text.Originality/value: New types of PGMs are described in the paper. Attention is paid mainly to materials with gradation of electrical and magnetic properties. The paper may be interesting for scientists involved in PGMs and for industry engineers looking for materials with electrical and magnetic properties gradation.Keywords: Multifunctional materials

  18. Trehalose and Trehalose-based Polymers for Environmentally Benign, Biocompatible and Bioactive Materials

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Shibata

    2008-08-01

    Full Text Available Abstract: Trehalose is a non-reducing disaccharide that is found in many organisms but not in mammals. This sugar plays important roles in cryptobiosis of selaginella mosses, tardigrades (water bears, and other animals which revive with water from a state of suspended animation induced by desiccation. The interesting properties of trehalose are due to its unique symmetrical low-energy structure, wherein two glucose units are bonded face-to-face by 1→1-glucoside links. The Hayashibara Co. Ltd., is credited for developing an inexpensive, environmentally benign and industrial-scale process for the enzymatic conversion of α-1,4-linked polyhexoses to α,α-D-trehalose, which made it easy to explore novel food, industrial, and medicinal uses for trehalose and its derivatives. Trehalosechemistry is a relatively new and emerging field, and polymers of trehalose derivatives appear environmentally benign, biocompatible, and biodegradable. The discriminating properties of trehalose are attributed to its structure, symmetry, solubility, kinetic and thermodynamic stability and versatility. While syntheses of trehalose-based polymer networks can be straightforward, syntheses and characterization of well defined linear polymers with tailored properties using trehalose-based monomers is challenging, and typically involves protection and deprotection of hydroxyl groups to attain desired structural, morphological, biological, and physical and chemical properties in the resulting products. In this review, we will overview known literature on trehalose’s fascinating involvement in cryptobiology; highlight its applications in many fields; and then discuss methods we used to prepare new trehalose-based monomers and polymers and explain their properties.

  19. Shelf life prediction of radiation sterilized polymeric materials

    International Nuclear Information System (INIS)

    The functional properties of many polymers employed in medical disposables are unaffected by sterilizing doses of ionizing radiation. However, some materials (PVC, polypropylene, cellulosics, etc.) undergo undesirable changes which continue to occur for the shelf life of the product. In many cases, conventional accelerated aging techniques do not accurately predict the real time properties of the materials. As real time aging is not generally practical, it has become necessary to develop accelerated aging techniques which can predict the functional properties of a material for the shelf life of the product. This presentation will address issues involved in developing these tests. Real time physical property data is compared to data generated by various acceleration methods. (author)

  20. Modeling of Slot Waveguide Sensors Based on Polymeric Materials

    Directory of Open Access Journals (Sweden)

    Lorenzo Pavesi

    2011-07-01

    Full Text Available Slot waveguides are very promising for optical sensing applications because of their peculiar spatial mode profile. In this paper we have carried out a detailed analysis of mode confinement properties in slot waveguides realized in very low refractive index materials. We show that the sensitivity of a slot waveguide is not directly related to the refractive index contrast of high and low materials forming the waveguide. Thus, a careful design of the structures allows the realization of high sensitivity devices even in very low refractive index materials (e.g., polymers to be achieved. Advantages of low index dielectrics in terms of cost, functionalization and ease of fabrication are discussed while keeping both CMOS compatibility and integrable design schemes. Finally, applications of low index slot waveguides as substitute of bulky fiber capillary sensors or in ring resonator architectures are addressed. Theoretical results of this work are relevant to well established polymer technologies.

  1. Characterization of Viscoelastic Properties of Polymeric Materials Through Nanoindentation

    Science.gov (United States)

    Odegard, G. M.; Bandorawalla, T.; Herring, H. M.; Gates, T. S.

    2003-01-01

    Nanoindentation is used to determine the dynamic viscoelastic properties of six polymer materials. It is shown that varying the harmonic frequency of the nanoindentation does not have any significant effect on the measured storage and loss moduli of the polymers. Agreement is found between these results and data from DMA testing of the same materials. Varying the harmonic amplitude of the nanoindentation does not have a significant effect on the measured properties of the high performance resins, however, the storage modulus of the polyethylene decreases as the harmonic amplitude increases. Measured storage and loss moduli are also shown to depend on the density of the polyethylene.

  2. Novel Nanostructured Electrodes Obtained by Pyrolysis of Composite Polymeric Materials

    DEFF Research Database (Denmark)

    Amato, Letizia; Schulte, Lars; Heiskanen, Arto;

    2015-01-01

    In this work, we compare pyrolyzed carbon derived from the photoresist SU‐8 alone or in combination with polystyrene and poly(styrene)‐block‐poly(dimethylsiloxane) copolymer (PS‐b‐PDMS), to be used as novel materials for micro‐ and nanoelectrodes. The pyrolyzed carbon films are evaluated with sca...

  3. High-performance polymeric materials for waveguide applications

    Science.gov (United States)

    Glukh, Konstantin; Lipian, John-Henry; Mimna, Richard; Neal, Phillip S.; Ravikiran, R.; Rhodes, Larry F.; Shick, Robert A.; Zhao, Xiao-Mei

    2000-11-01

    The ever-increasing need for economical, reliable, and high- performance optical interconnects for telecommunication and data communication markets demands new innovative solutions. Polymer technology being developed at BFGoodrich is focused on satisfying this demand. It is based on proprietary polynorbornene polymers that exhibit excellent optical, thermal and mechanical properties essential for fabrication of reliable components for integrated optics. Typical polymer waveguide systems exhibit a tradeoff between thermal and optical performance. The uniqueness of the polynorbornene system is that these tradeoffs are minimized. The intrinsic properties of the polynorbornene system include low transmission loss (2000 hours at 125 degree(s)C), high glass transition temperature (>280 degree(s)C), and low moisture absorption (market. Candidate materials have been identified as core and cladding components for optical waveguides. The refractive index of a typical core material is 1.53, and of a typical clad material, 1.50 at 820 nm. The difference in index between core and cladding is approximately 0.03 over a broad range of wavelength (515-870nm). Preliminary results indicate that the difference in index between core and cladding tracks with temperature, which is in line with out expectation since these polymers have similar structures at the molecular level. Fabrication of functional waveguides has been demonstrated using a conventional cast and cure process at the lab scale. Optical performance of the constituent materials and the waveguide devices will be discussed in the paper.

  4. Nanostructured Ti-Zr-Pd-Si-(Nb) bulk metallic composites: Novel biocompatible materials with superior mechanical strength and elastic recovery.

    Science.gov (United States)

    Hynowska, A; Blanquer, A; Pellicer, E; Fornell, J; Suriñach, S; Baró, M D; Gebert, A; Calin, M; Eckert, J; Nogués, C; Ibáñez, E; Barrios, L; Sort, J

    2015-11-01

    The microstructure, mechanical behaviour, and biocompatibility (cell culture, morphology, and cell adhesion) of nanostructured Ti45 Zr15 Pd35- x Si5 Nbx with x = 0, 5 (at. %) alloys, synthesized by arc melting and subsequent Cu mould suction casting, in the form of rods with 3 mm in diameter, are investigated. Both Ti-Zr-Pd-Si-(Nb) materials show a multi-phase (composite-like) microstructure. The main phase is cubic β-Ti phase (Im3m) but hexagonal α-Ti (P63/mmc), cubic TiPd (Pm3m), cubic PdZr (Fm3m), and hexagonal (Ti, Zr)5 Si3 (P63/mmc) phases are also present. Nanoindentation experiments show that the Ti45 Zr15 Pd30 Si5 Nb5 sample exhibits lower Young's modulus than Ti45 Zr15 Pd35 Si5 . Conversely, Ti45 Zr15 Pd35 Si5 is mechanically harder. Actually, both alloys exhibit larger values of hardness when compared with commercial Ti-40Nb, (HTi-Zr-Pd-Si ≈ 14 GPa, HTi-Zr-Pd-Si-Nb ≈ 10 GPa and HTi-40Nb ≈ 2.7 GPa). Concerning the biological behaviour, preliminary results of cell viability performed on several Ti-Zr-Pd-Si-(Nb) discs indicate that the number of live cells is superior to 94% in both cases. The studied Ti-Zr-Pd-Si-(Nb) bulk metallic system is thus interesting for biomedical applications because of the outstanding mechanical properties (relatively low Young's modulus combined with large hardness), together with the excellent biocompatibility. PMID:25533018

  5. Efficiency of two non-destructive testing methods to detect defects in polymeric materials

    Directory of Open Access Journals (Sweden)

    M. Szczepanik

    2010-02-01

    Full Text Available Purpose: The aim of this paper was to compare application possibilities of non-destructive ultrasonic and thermographic testing methods to detect defects in polymeric materials. In experimental part, subsurface defects were made in specimens of polymeric materials such as PE, PMMA, laminate then experimentally detected and directly displayed in ultrasonic and thermographic images.Design/methodology/approach: In this paper the development of a real-time non-invasive technique using pulsed infrared (IR thermography to measure the temperature of polymer materials is described. In this study 16 specimens were pre-heated during specific time using infrared lamp. After that the specimen’s surface temperature was scanned during cooling down process by a thermovision camera, then defects were detected by means of a thermographic images analysis. The second method applied was ultrasonic testing using the pulse-echo technique as a type of non-destructive testing commonly used to find flaws in materials and to measure the objects thickness. Frequencies of 2 to 10 MHz are common but for special purposes other frequencies are used.Findings: The experimental results have demonstrated that application of ultrasonic and thermographic testing are effective methods to visualize and reveal defects in the polymeric materials.Research limitations/implications: It is not possible to detect defects after a long pre-heating time of researched material because it results in uniform temperature on the whole surface of specimen. The most problems about identification of defects in tested materials by ultrasounds concern laminates.Originality/value: This paper is a unique because it compares two non-destructive testing methods usually used separately to detect defects in polymeric materials.

  6. Moisture effect on mechanical properties of polymeric composite materials

    Science.gov (United States)

    Airale, A. G.; Carello, M.; Ferraris, A.; Sisca, L.

    2016-05-01

    The influence of moisture on the mechanical properties of fibre-reinforced polymer matrix composites (PMCs) was investigated. Four materials had been take into account considering: both 2×2-Twill woven carbon fibre or glass fibre, thermosetting matrix (Epoxy Resin) or thermoplastic matrix (Polyphenylene Sulfide). The specimens were submitted for 1800 hours to a hygrothermic test to evaluate moisture absorption on the basis of the Fick's law and finally tested to verify the mechanical properties (ultimate tensile strength). The results showed that the absorbed moisture decreases those properties of composites which were dominated by the matrix or the interface, while was not detectable the influence of water on the considered fibre. An important result is that the diffusion coefficient is highest for glass/PPS and lowest for carbon/epoxy composite material. The results give useful suggestions for the design of vehicle components that are exposed to environmental conditions (rain, snow and humidity).

  7. Surface Modification of Polymeric Materials by Plasma Treatment

    OpenAIRE

    Castro Vidaurre E.F.; Achete C.A.; Gallo F.; Garcia D.; Simão R; Habert A.C.

    2002-01-01

    Low-temperature plasma treatment has been used in the last years as a useful tool to modify the surface properties of different materials, in special of polymers. In the present work low temperature plasma was used to treat the surface of asymmetric porous substrates of polysulfone (PSf) membranes. The main purpose of this work was to study the influence of the exposure time and the power supplied to argon plasma on the permeability properties of the membranes. Three rf power levels, respecti...

  8. Fracture mechanics of PVDF polymeric material : specimen geometry effects

    OpenAIRE

    Laiarinandrasana, Lucien; Hochstetter, Gilles; Lafarge, Mélanie

    2006-01-01

    Polyvinylidene fluoride (PVDF) is a semi-crystalline polymer that has been widely studied for structural applications, because it exhibits good mechanical properties and chemical resistance. During viscoplastic deformation, the material whitens after the onset of necking due to nucleation and growth of voids. Mechanical tests on cracked specimens show the crack instability on DENT specimens whereas stable crack growth on SENB specimens is also encountered. In the global approach of non linear...

  9. Thiol-containing polymeric embedding materials for nanoskiving

    OpenAIRE

    Mays, Robin L.; Pourhossein, Parisa; Savithri, Dhanalekshmi; Genzer, Jan; Chiechi, Ryan C.; Dickey, Michael D.

    2013-01-01

    This paper describes the characterization of new embedding resins for nanoskiving (ultramicrotomy) that contain thiols. Nanoskiving is a technique to produce nanoscale structures using an ultramicrotome to section thin films of materials (e. g., gold) embedded in polymer. Epoxies are used typically as embedding resins for microtomy. Epoxies, however, do not adhere well to gold or other smooth metallic structures that are used commonly for nanoskiving. Thiol-ene and thiol-epoxy polymers provid...

  10. Venom conjugated polylactide applied as biocompatible material for passive and active immunotherapy against scorpion envenomation.

    Science.gov (United States)

    Ayari-Riabi, Sana; Trimaille, Thomas; Mabrouk, Kamel; Bertin, Denis; Gigmes, Didier; Benlasfar, Zakaria; Zaghmi, Ahlem; Bouhaouala-Zahar, Balkiss; Elayeb, Mohamed

    2016-04-01

    Scorpion envenoming represents a public health issue in subtropical regions of the world. Treatment and prevention need to promote antitoxin immunity. Preserving antigenic presentation while removing toxin effect remains a major challenge in toxin vaccine development. Among particulate adjuvant, particles prepared with poly (d,l-lactide) polymer are the most extensively investigated due to their excellent biocompatibility and biodegradability. The aim of this study is to develop surfactant-free PLA nanoparticles that safely deliver venom toxic fraction to enhance specific immune response. PLA nanoparticles are coated with AahG50 (AahG50/PLA) and BotG50 (BotG50/PLA): a toxic fraction purified from Androctonus australis hector and Buthus occitanus tunetanus venoms, respectively. Residual toxicities are evaluated following injections of PLA-containing high doses of AahG50 (or BotG50). Immunization trials are performed with the detoxified fraction administered alone without adjuvant. A comparative study of the effect of Freund is also included. The neutralizing capacity of sera is determined in naive mice. Six months later, immunized mice are challenged subcutaneously with increased doses of AahG50. Subcutaneous lethal dose 50 (LD50) of AahG50 and BotG50 is of 575μg/kg and 1300μg/kg respectively. By comparison, BotG50/PLA is totally innocuous while 50% of tested mice survive 2875μg AahG50/kg. Alhydrogel and Freund are not able to detoxify such a high dose. Cross-antigenicity between particulate and soluble fraction is also, ensured. AahG50/PLA and BotG50/PLA induce high antibody levels in mice serum. The neutralizing capacity per mL of anti-venom was 258μg/mL and 186μg/mL calculated for anti-AahG50/PLA and anti-BotG50/PLA sera, respectively. Animals immunized with AahG50/PLA are protected against AahG50 injected dose of 3162μg/kg as opposed all non-immunized mice died at this dose. We find that the detoxification approach based PLA nanoparticles, benefit the

  11. Considerations for Contractile Electroactive Polymeric Materials and Actuators

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Lenore; Erickson, Carl J.; Meixler, Lewis D.; Ascione, George; Gentile, Charles A.; Tilson, Charles; Bernasek, Stephen L.; Abelev, Esta

    2009-06-16

    Ras Labs produces electroactive polymer (EAP) based materials and actuators that bend, swell, ripple and now contract (new development) with low electric input. This is an important attribute because of the ability of contraction to produce life-like motion. The mechanism of contraction is not well understood. Radionuclide-labeled experiments were conducted to follow the movement of electrolytes and water in these EAPs when activated. Extreme temperature experiments were performed on the contractile EAPs with very favorable results. One of the biggest challenges in developing these actuators, however, is the electrode-EAP interface because of the pronounced movement of the EAP. Plasma treatments of metallic electrodes were investigated in order to improve the attachment of the embedded electrodes to the EAP material. Surface analysis, adhesive testing, and mechanical testing were conducted to test metal surfaces and metal-polymer interfaces. The nitrogen plasma treatment of titanium produced a strong metal-polymer interface; however, oxygen plasma treatment of both stainless steel and titanium produced even stronger metal-polymer interfaces. Plasma treatment of the electrodes allows for the embedded electrodes and the EAP material of the actuator to work and move as a unit, with no detachment, by significantly improving the metal-polymer interface.

  12. Considerations for Contractile Electroactive Polymeric Materials and Actuators

    International Nuclear Information System (INIS)

    Ras Labs produces electroactive polymer (EAP) based materials and actuators that bend, swell, ripple and now contract (new development) with low electric input. This is an important attribute because of the ability of contraction to produce life-like motion. The mechanism of contraction is not well understood. Radionuclide-labeled experiments were conducted to follow the movement of electrolytes and water in these EAPs when activated. Extreme temperature experiments were performed on the contractile EAPs with very favorable results. One of the biggest challenges in developing these actuators, however, is the electrode-EAP interface because of the pronounced movement of the EAP. Plasma treatments of metallic electrodes were investigated in order to improve the attachment of the embedded electrodes to the EAP material. Surface analysis, adhesive testing, and mechanical testing were conducted to test metal surfaces and metal-polymer interfaces. The nitrogen plasma treatment of titanium produced a strong metal-polymer interface; however, oxygen plasma treatment of both stainless steel and titanium produced even stronger metal-polymer interfaces. Plasma treatment of the electrodes allows for the embedded electrodes and the EAP material of the actuator to work and move as a unit, with no detachment, by significantly improving the metal-polymer interface

  13. Effects of atomic oxygen on polymeric materials flown on EOIM-3

    Science.gov (United States)

    Kamenetzky, Rachel R.; Linton, Roger C.; Finckenor, Miria M.; Vaughn, Jason A.

    1995-01-01

    Diverse polymeric materials, including several variations of Kapton, were flown on STS-46 as part of the Evaluation of Oxygen Interaction with Materials Experiment (EOIM-3). These materials were flown in the cargo bay and exposed to the space environment July 31 - August 8, 1992, including 40 hours of direct atomic oxygen impingement. The atomic oxygen exposure was approximately 2.2 x 10(exp 20) atoms/sq cm. Polymeric materials flown on EOIM-3 include coated and uncoated Kapton, Tefzel ETFE, Lexan, FEP and TFE Teflon, bulk Halar and PEEK, S383 silicone and Viton elastomeric seal material. Analyses performed included thickness measurements using Dektak and eddy current methods, mass loss, resistance, permeability, hardness, and FTIR. The effects of stress and the space environment on Kapton were also evaluated. Previous EOIM missions on STS-5 and STS-8 and the Long Duration Exposure Facility also contained polymeric material samples. Data from these previous flights are shown for comparison, as well as ground simulation of space environment effects using both thermal energy flow tubes and 5 eV neutral atomic oxygen beam facilities. Reaction efficiencies for the various atomic oxygen exposure conditions are discussed.

  14. Effects of atomic oxygen on polymeric materials flown on EOIM-3

    Energy Technology Data Exchange (ETDEWEB)

    Kamenetzky, R.R.; Linton, R.C.; Finckenor, M.M.; Vaughn, J.A.

    1995-02-01

    Diverse polymeric materials, including several variations of Kapton, were flown on STS-46 as part of the Evaluation of Oxygen Interaction with Materials Experiment (EOIM-3). These materials were flown in the cargo bay and exposed to the space environment July 31 - August 8, 1992, including 40 hours of direct atomic oxygen impingement. The atomic oxygen exposure was approximately 2.2 x 10(exp 20) atoms/sq cm. Polymeric materials flown on EOIM-3 include coated and uncoated Kapton, Tefzel ETFE, Lexan, FEP and TFE Teflon, bulk Halar and PEEK, S383 silicone and Viton elastomeric seal material. Analyses performed included thickness measurements using Dektak and eddy current methods, mass loss, resistance, permeability, hardness, and FTIR. The effects of stress and the space environment on Kapton were also evaluated. Previous EOIM missions on STS-5 and STS-8 and the Long Duration Exposure Facility also contained polymeric material samples. Data from these previous flights are shown for comparison, as well as ground simulation of space environment effects using both thermal energy flow tubes and 5 eV neutral atomic oxygen beam facilities. Reaction efficiencies for the various atomic oxygen exposure conditions are discussed.

  15. The influence of ionizing radiation on the formation of polymeric material from aqueous malononitrile

    International Nuclear Information System (INIS)

    The CN group might have made it appearance in the early stages of chemical evolution, for this reason the radiolytic behavior of nitriles have relevance to the study of prebiotic chemistry. A systematic study of the influence of the irradiation on nitriles and dinitriles have been carried at ICN. In this paper we present the formation of polymeric material from the γ irradiation of aqueous solutions of malonitrile 0.1 M, oxygen free, at their natural ph s. The analysis of the radiolytic product was by exclusion chromatography, some characteristics of the polymer material were found by IR spectroscopy, Biuret test, etc. The results showed that in this system several polymeric materials are formed with a molecular weight about 10,000 daltons. (Author)

  16. Luminescence of novel terbium complex/inorganic/polymeric hybrid materials based on sol–gel technology

    International Nuclear Information System (INIS)

    Highlights: ► A new kind of ternary rare earth/inorganic/organic polymeric hybrid materials with covalent bonds was prepared. ► Polyvinyl alcohol was introduced into the hybrids through the polycondensation reactions. ► The rare-earth complex and polymer were connected by the Si-O bonds. ► It is possible to provide an excellent route to obtain optical functional hybrid materials. - Abstract: In this paper, a new terbium complex/inorganic/polymeric molecular hybrid material was prepared and its optical properties were studied. At first, 4-nitrobenzoic acid was modified by (3-aminopropyl) trimethoxysilane to form a precursor and coordinated with terbium ion. Then it was polymerized with inorganic host tetraethoxysilane or polymer host polyvinyl alcohol and formed hybrid material. 1H NMR Fourier transform infrared (FT-IR), scanning electron microscope and TGA were applied to characterize the structure of the precursor. UV–vis spectrophotometer and fluorescence spectra were applied to characterize the photophysical properties of the obtained hybrid material. The strong luminescence of Tb3+ substantiates optimum energy couple and effective intramolecular energy transfer between the triplet state energy of modified ligand bridge and emissive energy level of Tb3+.

  17. Luminescence of novel terbium complex/inorganic/polymeric hybrid materials based on sol-gel technology

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Limin, E-mail: zhaolimin@lcu.ecu.cn [College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059 (China); Shao Xin; Yin Yibin; Li Wenzhi [College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059 (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer A new kind of ternary rare earth/inorganic/organic polymeric hybrid materials with covalent bonds was prepared. Black-Right-Pointing-Pointer Polyvinyl alcohol was introduced into the hybrids through the polycondensation reactions. Black-Right-Pointing-Pointer The rare-earth complex and polymer were connected by the Si-O bonds. Black-Right-Pointing-Pointer It is possible to provide an excellent route to obtain optical functional hybrid materials. - Abstract: In this paper, a new terbium complex/inorganic/polymeric molecular hybrid material was prepared and its optical properties were studied. At first, 4-nitrobenzoic acid was modified by (3-aminopropyl) trimethoxysilane to form a precursor and coordinated with terbium ion. Then it was polymerized with inorganic host tetraethoxysilane or polymer host polyvinyl alcohol and formed hybrid material. {sup 1}H NMR Fourier transform infrared (FT-IR), scanning electron microscope and TGA were applied to characterize the structure of the precursor. UV-vis spectrophotometer and fluorescence spectra were applied to characterize the photophysical properties of the obtained hybrid material. The strong luminescence of Tb{sup 3+} substantiates optimum energy couple and effective intramolecular energy transfer between the triplet state energy of modified ligand bridge and emissive energy level of Tb{sup 3+}.

  18. Friction Behaviour of Polymeric Composite Materials Mixed with Carbon Fibers Having Different Orientations Layout

    Science.gov (United States)

    Caliman, R.

    2016-06-01

    This paper presents a study of the friction properties of polymeric composite materials reinforced with unidirectional carbon fibers having different stratified structure. So, the composites are complex and versatile materials but their behaviour in practice is not fully studied. For instance, these polymeric composite materials mixed with carbon fibers after being investigated in terms of wear, did not elucidate the effect of fiber orientation on wear properties. Is therefore necessary to investigate the effect of carbon fibers orientation on the friction-wear properties of the reinforced composite materials tested to abrasive and adhesive friction. Research work has been done with unidirectional composite materials having overlap 18 successive layers made from a polymeric resine and 60% of carbon fibers. The stratified structure was obtained by compressing multiple pre-impregnated strips, positioned manually. During this experimental work, three types of test samples were investigated: parallel, normal and anti-parallel, taking in consideration the carbon fibre orientation with respect to the sliding direction. The friction coefficient is computed function to the friction load and loading value. Also, the specific wear rate was calculated according to: the mass loss, density, the normal contact surface, the sliding distance and load rating.

  19. Surface Modification of Polymeric Materials by Plasma Treatment

    Directory of Open Access Journals (Sweden)

    E.F. Castro Vidaurre

    2002-03-01

    Full Text Available Low-temperature plasma treatment has been used in the last years as a useful tool to modify the surface properties of different materials, in special of polymers. In the present work low temperature plasma was used to treat the surface of asymmetric porous substrates of polysulfone (PSf membranes. The main purpose of this work was to study the influence of the exposure time and the power supplied to argon plasma on the permeability properties of the membranes. Three rf power levels, respectively 5, 10 and 15 W were used. Treatment time ranged from 1 to 50 min. Reduction of single gas permeability was observed with Ar plasma treatments at low energy bombardment (5 W and short exposure time (20 min. Higher power and/or higher plasma exposition time causes a degradation process begins. The chemical and structural characterization of the membranes before and after the surface modification was done by AFM, SEM and XPS.

  20. Selection of Easily Accessible PCR- and Bio-Compatible Materials for Microfluidic Chips

    KAUST Repository

    Xiao, Kang

    2013-10-30

    Conventional fabrication of microfluidic chip is a complicated and time, effort and material consuming process. Consequently, due to high expenses, it has poor applicability for performing mass biological analysis by microfluidics. In this study, we repor

  1. Physical properties and biocompatibility of UHMWPE-derived materials modified by synchrotron radiation

    OpenAIRE

    Bykova, Iu.; Weinhardt, V.; Kashkarova, A.; Lebedev, S.; Baumbach, T.; Pichugin, V.; Zaitsev, K.; Khlusov, I.

    2014-01-01

    The applications of synchrotron radiation (SR) in medical imaging have become of great use, particularly in angiography, bronchography, mammography, computed tomography, and X-ray microscopy. Thanks to recently developed phase contrast imaging techniques non-destructive preclinical testing of low absorbing materials such as polymers has become possible. The focus of the present work is characterization and examination of UHMWPE-derived materials widely used in medicine, before and after their...

  2. Biocompatibility of Titanium

    Science.gov (United States)

    Namavar, Fereydoon; Sabirianov, Renat; Marton, Denes; Rubinstein, Alexander; Garvin, Kevin

    2012-02-01

    Titanium is the material of choice for orthopaedic applications because of its known biocompatibility. In order to enhance osteogenic properties of the Ti implants, it is necessary to understand the origin of its biocompatibility. We addresses the origin of Ti biocompatibility through (1) theoretical modeling, (2) the precise determination of Ti surface chemistry by X-ray photoelectron spectroscopy (XPS), (3) and the study of fibronectin adsorption as a function of Ti (near) surface chemistry by Enzyme-linked immunosorbent assay (ELISA). We compare the protein adsorption on Ti with the native oxide layer and the one coated by TiO2 in anatase phase using ion beam assisted deposition (IBAD). We show that the thin native sub-stoichiometric titanium oxide layer is crucial for biocompatibility of Ti surface. This is due to the enhancement of the non-specific adsorption of proteins which mediate cell adhesion. Improving the surface oxide quality, i.e. fabricating stoichiometric TiO2 (using IBAD) as well as nanoengineering the surface topology that matches its dimensions to that of adhesive proteins, is crucial for increased protein adsorption and, as a result, further increases biocompatibility of Ti implant materials.

  3. Liquid crystals. Oligomeric and polymeric materials for soft photonic technologies

    International Nuclear Information System (INIS)

    The current pace of today's information technologies might lead the casual observer to believe that this is all new. However the reality is that, as with most things, this is really a long evolution of processes based on tried, tested and re-adapted techniques. This thesis represents 12 years of predominantly technology driven research and covers a whole range of characterising, evaluating and fabricating devices based on liquid crystalline systems. Firstly polymer liquid crystals are discussed with respect to the fabrication of a flexible substrate display based on standard printing techniques and this is shown to have improved display viewing properties over a standard polymer dispersed liquid crystal (PDLC) device. Following on from this work is presented that involves the production of regular grid arrays in isotropic polymers that are used as control structures in nematic liquid crystal systems. This progresses onto a now patented device that allows the production of robust ferroelectric devices based on PDLC technology. Whilst the development of production techniques is important for the advancement of devices it would not be possible to keep up the pace without continued research into the basic liquid crystalline systems. The final chapter reviews work currently under supervision of the author based on flexoelectric effects in symmetric bimesogens. These materials possess responses times of the order of ∼100μs with an effective optic axis switching angle that is linear with the applied field and can be in well in excess of 90 deg. (author)

  4. The radiation chemistry of advanced polymeric materials containing fluorine

    Energy Technology Data Exchange (ETDEWEB)

    Forsythe, J.S.; Hill, D.J.T.; Whittaker, A.K. [Queensland Univ., St. Lucia, QLD (Australia). Dept. of Chemistry; Logothetis, A.L. [Du Pont, Central Research and Development, Experimental Station, Wilmington, DE (United States)

    1996-12-31

    Full text: TFE/PMVE (tetrafluoroethylene/perfluoromethylvinyl ether) is a commercial perfluoroelastomer marketed by the Du Pont Company under the trade-name Kalrez. Very little is known about the radiation chemistry of this fluoropolymer which in general is consistent with all fluoropolymers. In 1984, Uschold, while attempting to graft vinyl monomers onto irradiated TFE/PMVE, found that the fluoroelastomer crosslinked forming and insoluble network. Unfortunately, Uschold found that the mechanical properties of irradiated TFE/PMVE were inferior when compared to the chemically crosslinked analogues because of the simultaneous radiation scissioning of the polymer chain. This chemical curing is described elsewhere. The radiation crosslinking of TFE/PMVE was also briefly studied by Luo et al. and later by Sun et al. but they exclusively looked at the sol/gel behaviour. Recently Lyons reviewed the radiation chemistry of fluoropolymers and showed that most research solely focused on the physical properties of the cured material and little attention placed on the development of mechanisms of radiation chemistry. In this study, we have employed both physical and chemical techniques such as tensile tests and {sup 19}F NMR to formulate a radiation mechanism describing both chain scission and crosslinking processes. {sup 19}F NMR identified and quantified new functionalities such as carboxylic acid and saturated chain ends. The crosslinking reaction has been tentatively postulated for the first time. Factors affecting the radiation chemistry such as the presence of oxygen and irradiation temperature will be briefly discussed. 5 refs., 2 figs.

  5. Development of eco-friendly polymeric materials by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae-hak; Shim, Kihyung; Kim, Jaeyoung; and others

    2012-12-15

    In this project, the core technologies such as fabrication of eco-friendly and high-performance bioplastics, anionic exchange membranes for the energy generation, and anisotropic conductive films (ACF) for the electronic devices were developed by using an eco-friendly and low-energy consumption radiation. In the 1{sup st} project group, the fabrication technologies of biodegradable polymer-based blends, biocompoistes, and foam were developed using a radiation crosslinking technology, and the possibility of their commercialization was evaluated through the fabrication of prototype products (fruits packaging material and adhesive) in the practical production lines. In the 2{sup nd} project group, the fabrication technology of the anion exchange membranes for alkaline fuel cell were prepared by utilizing the inherent property of radiation such as high ionizing energy and penetrating depth. The ion exchange capacity, ion conductivity, high ionizing energy and penetrating depth. The ion exchange capacity, ion conductivity, high ionizing energy and penetrating depth. The ion exchange capacity, ion conductivity, mechanical property, and chemical stability of the prepared membranes were measured. The results of the MEA performance test, the maximum power density of 115 mW and operation for 200 hours, indicates the possibility of the use of anion exchange membranes for alkaline fuel cell. In the 3rd project group, the electron beam-induced room temperature and fast curable epoxy was developed and the mechanism of electron beam-induced curing was investigated using various analytical methods. On the basis of the physical and electrical characterization, the prepared ACF exhibited lower resistance and higher tensile strength compared to that of the commercialized one.

  6. Development of eco-friendly polymeric materials by radiation

    International Nuclear Information System (INIS)

    In this project, the core technologies such as fabrication of eco-friendly and high-performance bioplastics, anionic exchange membranes for the energy generation, and anisotropic conductive films (ACF) for the electronic devices were developed by using an eco-friendly and low-energy consumption radiation. In the 1st project group, the fabrication technologies of biodegradable polymer-based blends, biocompoistes, and foam were developed using a radiation crosslinking technology, and the possibility of their commercialization was evaluated through the fabrication of prototype products (fruits packaging material and adhesive) in the practical production lines. In the 2nd project group, the fabrication technology of the anion exchange membranes for alkaline fuel cell were prepared by utilizing the inherent property of radiation such as high ionizing energy and penetrating depth. The ion exchange capacity, ion conductivity, high ionizing energy and penetrating depth. The ion exchange capacity, ion conductivity, high ionizing energy and penetrating depth. The ion exchange capacity, ion conductivity, mechanical property, and chemical stability of the prepared membranes were measured. The results of the MEA performance test, the maximum power density of 115 mW and operation for 200 hours, indicates the possibility of the use of anion exchange membranes for alkaline fuel cell. In the 3rd project group, the electron beam-induced room temperature and fast curable epoxy was developed and the mechanism of electron beam-induced curing was investigated using various analytical methods. On the basis of the physical and electrical characterization, the prepared ACF exhibited lower resistance and higher tensile strength compared to that of the commercialized one

  7. Surface modification of polymeric materials by cold atmospheric plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Kostov, K.G., E-mail: kostov@feg.unesp.br [Faculty of Engineering in Guaratinguetá–FEG, Universidade Estadual Paulista–UNESP Guaratiguetá, 12516-410, SP (Brazil); Nishime, T.M.C.; Castro, A.H.R. [Faculty of Engineering in Guaratinguetá–FEG, Universidade Estadual Paulista–UNESP Guaratiguetá, 12516-410, SP (Brazil); Toth, A. [Institute of Material and Environmental Chemistry, Hungarian Academy of Science P.O. Box 17, H-1525, Budapest (Hungary); Hein, L.R.O. [Faculty of Engineering in Guaratinguetá–FEG, Universidade Estadual Paulista–UNESP Guaratiguetá, 12516-410, SP (Brazil)

    2014-09-30

    Highlights: • We investigate polymer surface modification by atmospheric pressure plasma jet APPJ. • Jet operation conditions for uniform surface modification were determined. • The APPJ added O atoms to the polymer surface and also enhanced the roughness. • The degree of polymer surface modification by APPJ and DBD were compared. • The APPJ is more efficient in attaching O atoms and produces less polymer fragments. - Abstract: In this work we report the surface modification of different engineering polymers, such as, polyethylene terephthalate (PET), polyethylene (PE) and polypropylene (PP) by an atmospheric pressure plasma jet (APPJ). It was operated with Ar gas using 10 kV, 37 kHz, sine wave as an excitation source. The aim of this study is to determine the optimal treatment conditions and also to compare the polymer surface modification induced by plasma jet with the one obtained by another atmospheric pressure plasma source – the dielectric barrier discharge (DBD). The samples were exposed to the plasma jet effluent using a scanning procedure, which allowed achieving a uniform surface modification. The wettability assessments of all polymers reveal that the treatment leads to reduction of more than 40° in the water contact angle (WCA). Changes in surface composition and chemical bonding were analyzed by x-ray photoelectron spectroscopy (XPS) and Fourier-Transformed Infrared spectroscopy (FTIR) that both detected incorporation of oxygen-related functional groups. Surface morphology of polymer samples was investigated by Atomic Force Microscopy (AFM) and an increase of polymer roughness after the APPJ treatment was found. The plasma-treated polymers exhibited hydrophobic recovery expressed in reduction of the O-content of the surface upon rinsing with water. This process was caused by the dissolution of low molecular weight oxidized materials (LMWOMs) formed on the surface as a result of the plasma exposure.

  8. Electrical properties of polymeric gradient materials based on epoxy resin filled with hard coal

    Directory of Open Access Journals (Sweden)

    J. Stabik

    2010-01-01

    Full Text Available Purpose: of this paper was to describe functionally the gradient polymeric materials and technology of the gradient production. The experimental part describes preparation of circular disc samples of polymeric gradient material by gravity casting method. Finally electrical surface resistance and surface resistivity was measured and analysed.Design/methodology/approach: Eight specimens were prepared using gravity casting method. Composites with epoxy resin as a matrix and with respectively 3, 6, 9 and 12%vol of two types of hard coal as a filler were cast. Surface resistivity was applied as a measure of electrical properties. The idea of the test was to define electrical resistivity in sequential layers with different content and type of conductive component (hard coal. First, specimen’s thickness was measured and electrical resistivity was tested. Next, outer layer was removed by grinding and electrical measurements performed. The procedure was repeated for all subsequent layers. In effect, dependence of surface resistivity on depth of the layer was determined.Findings: The experimental results demonstrated that addition of conductive filler (hard coal to epoxy resin caused a change of surface resistivity of these materials. Hard coal together with epoxy resin formed gradient composite material with different filler content in subsequent layers.Research limitations/implications: Further investigations with higher hard coal content and/or with different matrix are needed.Originality/value: This paper is original because in the research programme electrical properties of new type of polymeric gradient composites were tested and presented in it.

  9. Precision synthesis of functional materials via RAFT polymerization and click-type chemical reactions

    Science.gov (United States)

    Flores, Joel Diez

    2011-12-01

    The need to tailor polymeric architectures with specific physico-chemical properties via the simplest, cleanest, and most efficient synthetic route possible has become the ultimate goal in polymer synthesis. Recent progress in macromolecular science, such as the discoveries of controlled/"living" free radical polymerization (CRP) methods, has brought about synthetic capabilities to prepare (co)polymers with advanced topologies, predetermined molecular weights, narrow molecular weight distributions, and precisely located functional groups. In addition, the establishment of click chemistry has redefined the selected few highly efficient chemical reactions that become highly useful in post-polymerization modification strategies. Hence, the ability to make well-defined topologies afforded by controlled polymerization techniques and the facile incorporation of functionalities along the chain via click-type reactions have yielded complex architectures, allowing the investigation of physical phenomena which otherwise could not be studied with systems prepared via conventional methods. The overarching theme of the research work described in this dissertation is the fusion of the excellent attributes of reversible addition-fragmentation chain transfer (RAFT) polymerization method, which is one of the CRP techniques, and click-type chemical reactions in the precision of synthesis of advanced functional materials. Chapter IV is divided into three sections. In Section I, the direct RAFT homopolymerization of 2-(acryloyloxy)ethyl isocyanate (AOI) and subsequent post-polymerization modifications are described. The polymerization conditions were optimized in terms of the choice of RAFT chain transfer agent (CTA), polymerization temperature and the reaction medium. Direct RAFT polymerization of AOI requires a neutral CTA, and relatively low reaction temperature to yield AOI homopolymers with low polydispersities. Efficient side-chain functionalization of PAOI homopolymers was

  10. Polymeric variable optical attenuators based on magnetic sensitive stimuli materials

    International Nuclear Information System (INIS)

    Magnetically-actuable, polymer-based variable optical attenuators (VOA) are presented in this paper. The design comprises a cantilever which also plays the role of a waveguide and the input/output alignment elements for simple alignment, yet still rendering an efficient coupling. Magnetic properties have been conferred to these micro-opto-electromechanical systems (MOEMS) by implementing two different strategies: in the first case, a magnetic sensitive stimuli material (M-SSM) is obtained by a combination of polydimethylsiloxane (PDMS) and ferrofluid (FF) in ratios between 14.9 wt % and 29.9 wt %. An M-SSM strip under the waveguide-cantilever, defined with soft lithography (SLT), provides the required actuation capability. In the second case, specific volumes of FF are dispensed at the end of the cantilever tip (outside the waveguide) by means of inkjet printing (IJP), obtaining the required magnetic response while holding the optical transparency of the waveguide-cantilever. In the absence of a magnetic field, the waveguide-cantilever is aligned with the output fiber optics and thus the intrinsic optical losses can be obtained. Numerical simulations, validated experimentally, have shown that, for any cantilever length, the VOAs defined by IJP present lower intrinsic optical losses than their SLT counterparts. Under an applied magnetic field (Bapp), both VOA configurations experience a misalignment between the waveguide-cantilever and the output fiber optics. Thus, the proposed VOAs modulate the output power as a function of the cantilever displacement, which is proportional to Bapp. The experimental results for the three different waveguide-cantilever lengths and six different FF concentrations (three per technology) show maximum deflections of 220 µm at 29.9 wt % of FF for VOASLT and 250 µm at 22.3 wt % FF for VOAIJP, at 0.57 kG for both. These deflections provide maximum actuation losses of 16.1 dB and 18.9 dB for the VOASLT and VOAIJP

  11. Bioactive Polymeric Composites for Tooth Mineral Regeneration: Physicochemical and Cellular Aspects

    OpenAIRE

    Joseph M. Antonucci; Drago Skrtic

    2011-01-01

    Our studies of amorphous calcium phosphate (ACP)-based dental materials are focused on the design of bioactive, non-degradable, biocompatible, polymeric composites derived from acrylic monomer systems and ACP by photochemical or chemically activated polymerization. Their intended uses include remineralizing bases/liners, orthodontic adhesives and/or endodontic sealers. The bioactivity of these materials originates from the propensity of ACP, once exposed to oral fluids, to release Ca and PO4 ...

  12. Research work of radiation induced graft polymerization for synthesis and modification of polymer materials in CRICI

    International Nuclear Information System (INIS)

    The direct and post radiation induced graft polymerization had been studied in CRICI (Chenguan Research Institute of Chemical Industry). The method consists of irradiation of various polymer substrates in the presence (or absence) of monomers in a liquid, saturated vapour or gaseous and non-saturated vapour. 1. Grafting of functional monomers. --- It is possible to divide the grafting into two main approaches for synthesis of functional polymer materials. The first is grafting of monomers attached required functional group such as unsaturated carboxylic acid (acrylic and methacrylic acid), unsaturated nitrogen containing (alkali) base (vinylpyridine), monomers with hydrophilic unionized and polar groups (acrylamide, N-vinylpyrrolidone glycidylmethacrylate) and so on. The second is grafting of monomers capable of continuing chemical modification after graft polymerization. This approach essentially expands synthetic possibility of RGP for preparing functional polymers. 2. The effect of some salts on aqueous solution graft polymerization. The grafting of AA or AAm onto PE by direct or post radiation method in the presence of Mohr's salt or cupric nitrate was studied in detail. 3. Radiation induced graft polymerization by gaseous phase of monomers. This method consists of irradiation or preirradiation of various polymer substrates in the presence (or absence for preirradiation) of monomer in a gaseous of nonsaturated vapour state. (J.P.N.)

  13. PCR biocompatibility of Lab-on-a-chip and MEMS materials

    DEFF Research Database (Denmark)

    Christensen, Troels Balmer; Pedersen, Christian Møller; Grøndahl, K. G.;

    2007-01-01

    DNA amplification using the polymerase chain reaction (PCR) is an important tool in biotechnology, pathogen surveillance in food, medical and forensic science etc. The PCR technique is now an important part of the research in and development of miniaturized biochemical analysis systems. However......, reduced or no DNA amplification at all is an important challenge for microfabricated PCR devices due to a negative interaction between PCR chemicals and the surrounding environment, i.e. the materials encapsulating the PCR mix. Materials of special interest regarding PCR compatibility are silicon, glass...... and polymers, which are important in the fabrication of microelectromechanical systems (MEMS), micro total analysis systems (mu TAS) and lab-on-a-chip (LOC) systems. The PCR inhibition effect is a particularly important phenomenon in microsystems due to an increased surface-to-volume ratio which...

  14. On the Use of Accelerated Aging Methods for Screening High Temperature Polymeric Composite Materials

    Science.gov (United States)

    Gates, Thomas S.; Grayson, Michael A.

    1999-01-01

    A rational approach to the problem of accelerated testing of high temperature polymeric composites is discussed. The methods provided are considered tools useful in the screening of new materials systems for long-term application to extreme environments that include elevated temperature, moisture, oxygen, and mechanical load. The need for reproducible mechanisms, indicator properties, and real-time data are outlined as well as the methodologies for specific aging mechanisms.

  15. Micro-Scale Thermal Imaging of Organic and Polymeric Materials with Cooled and Uncooled Infrared Cameras

    Directory of Open Access Journals (Sweden)

    J. Morikawa

    2012-01-01

    Full Text Available The emissivity corrected thermal imaging combined with a real-time direct imposed-signal system on the freezing of biological cells is presented, which makes it possible to visualize the exothermic latent heat at a minus temperature. The applicability of the uncooled micro bolometer (thermal detector to the micro-scale thermal analysis on the phase transitions of organic and polymeric materials is discussed in comparison with the photon detector, equipped with the optics originally designed.

  16. Structural and Electrochemical Properties of Functionalized Nanocellulose Materials and Their Biocompatibility

    OpenAIRE

    Carlsson, Daniel O.

    2014-01-01

    Nanocellulose has received considerable interest during the last decade because it is renewable and biodegradable, and has excellent mechanical properties, nanoscale dimensions and wide functionalization possibilities. It is considered to be a unique and versatile platform on which new functional materials can be based. This thesis focuses on nanocellulose from wood (NFC) and from Cladophora algae (CNC), functionalized with surface charges or coated with the conducting polymer polypyrrole (PP...

  17. Micromechanical properties of biocompatible materials for bone tissue engineering produced by direct 3D printing

    Czech Academy of Sciences Publication Activity Database

    Koudelka_ml., P.; Doktor, T.; Kytýř, Daniel; Fenclová, Nela; Šepitka, J.; Lukeš, J.

    Vol. 662. Durnten: Trans Tech Publications, 2015 - (Kovalčíková, A.; Lofaj, F.), s. 138-141 ISBN 978-3-03835-555-7. ISSN 1013-9826. [Conference on Local Mechanical Properties (LMP 2014) /11./. Stará Lesná (SK), 12.11.2014-14.11.2014] Institutional support: RVO:68378297 Keywords : bone scaffold * nanoindenation * mechanical properties * additive manufacturing Subject RIV: JJ - Other Materials http://www.scientific.net/KEM.662.138

  18. A novel method to control hydrolytic degradation of nanocomposite biocompatible materials via imparting superhydrophobicity

    Science.gov (United States)

    Khakbaz, Mobina; Hejazi, Iman; Seyfi, Javad; Jafari, Seyed-Hassan; Khonakdar, Hossein Ali; Davachi, Seyed Mohammad

    2015-12-01

    Acceleration of hydrolytic degradation of biomedical materials is not always desirable. For instance, terpolymers based on L-lactide, glycolide and trimethylene carbonate exhibit very fast hydrolytic degradation due to their amorphous structure, hydrophilicity, and high water absorption capability. Therefore, an attempt was made in the current study to impede the hydrolytic degradation for these materials through imparting superhydrophobicity to their surfaces. The used terpolymer has been shown to have promising potential applications as bio-absorbable surgical sutures and other biomedical materials, and thus, its applicability could be further extended upon impeding its hydrolytic degradation. Moreover, a novel method including combined use of non-solvent and nanoparticles was utilized to achieve superhydrophobicity. Very diverse wettability results were obtained which were attributed to the obtained various morphologies according to scanning electron microscopy results. More importantly, a unique hierarchical morphology was found to be responsible for the observed water repellent behavior. X-ray photoelectron spectroscopy results revealed co-existence of nanosilica particles and terpolymer chains on the surface's top layer. Finally, it was found that the superhydrophobic sample exhibited a significantly impeded hydrolytic degradation as compared with the hydrophilic pure terpolymer which was attributed to the formation of air pockets on the surface's top layer.

  19. Surface modification of traditional and bioresorbable metallic implant materials for improved biocompatibility

    Science.gov (United States)

    Walker, Emily K.

    Due to their strength, elasticity, and durability, a variety of metal alloys are commonly used in medical implants. Traditionally, corrosion-resistant metals have been preferred. These permanent materials can cause negative systemic and local tissue effects in the long-term. Permanent stenting can lead to late-stent thrombosis and in-stent restenosis. Metallic pins and screws for fracture fixation can corrode and fail, cause loss of bone mass, and contribute to inflammation and pain at the implant site, requiring reintervention. Corrodible metallic implants have the potential to prevent many of these complications by providing transient support to the affected tissue, dissolving at a rate congruent with the healing of the tissue. Alloys of iron and manganese (FeMn) exhibit similar fatigue strength, toughness, and elasticity compared with 316L stainless steel, making them very attractive candidates for bioresorbable stents and temporary fracture fixation devices. Much attention in recent years has been given to creating alloys with ideal mechanical properties for various applications. Little work has been done on determining the blood compatibility of these materials or on examining how their surfaces can be improved to improve cell adhesion, however. We examined thethrombogenic response of blood exposed to various resorbable ferrous stent materials through contact with porcine blood. The resorbable materials induced comparable or lower levels of several coagulation factors compared with 316L stainless steel. Little platelet adhesion was observed on any of the tested materials. Endothelialization is an important process after the implantation of a vascular stent, as it prevents damage to the vessel wall that can accelerate neointimal hyperplasia. Micromotion can lead to the formation of fibrous tissue surrounding an orthopedic implant, loosening, and ultimately failure of the implant. Nanoscale features were created on the surfaces of noble metal coatings, silicon

  20. Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

    International Nuclear Information System (INIS)

    There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×1013 to 5×1014 cm−2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet–visible (UV–vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed. - Highlights: ► Effect of 1 MeV He-ion bombardment on the surface properties of UHMWPE was studied. ► Change in the surface layer composition of UHMWPE due ion beam has been investigated. ► Ion beam bombardment improves the surface free energy of UHMWPE.

  1. Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

    Science.gov (United States)

    Abdul-Kader, A. M.; El-Gendy, Y. A.; Al-Rashdy, Awad A.

    2012-07-01

    There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×1013 to 5×1014 cm-2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet-visible (UV-vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed.

  2. PCR biocompatibility of lab-on-a-chip and MEMS materials

    Science.gov (United States)

    Christensen, T. B.; Pedersen, C. M.; Gröndahl, K. G.; Jensen, T. G.; Sekulovic, A.; Bang, D. D.; Wolff, A.

    2007-08-01

    DNA amplification using the polymerase chain reaction (PCR) is an important tool in biotechnology, pathogen surveillance in food, medical and forensic science etc. The PCR technique is now an important part of the research in and development of miniaturized biochemical analysis systems. However, reduced or no DNA amplification at all is an important challenge for microfabricated PCR devices due to a negative interaction between PCR chemicals and the surrounding environment, i.e. the materials encapsulating the PCR mix. Materials of special interest regarding PCR compatibility are silicon, glass and polymers, which are important in the fabrication of microelectromechanical systems (MEMS), micro total analysis systems (µTAS) and lab-on-a-chip (LOC) systems. The PCR inhibition effect is a particularly important phenomenon in microsystems due to an increased surface-to-volume ratio which enhances the possibility of interaction between the surfaces and ingredients in the PCR mixture. By proper surface treatment the PCR reaction can be facilitated and in this paper we present a systematic and quantitative study of the impact on the PCR compatibility of a chemical and a biological surface treatment. The chemical treatments are based on the silanizing agent dichlordimethylsilane [(CH3)2SiCl2

  3. Biodeuterated microbial chitosan for characterisation by neutron scattering and development of new biocompatible materials

    International Nuclear Information System (INIS)

    Chitosan is one of the most abundant natural polysaccharides on earth and has found a wide range of applications in biomedical and environmental fields. The most common source of commercially available chitosan is produced through the deacetylation of chitin from crustacean (mostly shrimp) shells. However, chitosan (along with chitin) is also a major component of the cell walls of a range of fungi, which can be grown and processed under controlled conditions to influence the degree of deacetylation and molecular weight of the extracted chitosan. We have selected the single cell yeast Pichia pastoris, which can also be used for recombinant expression of biodeuterated proteins. P. pastoris was cultivated in a bioreactor using deuterated methanol (CD3OD,) as sole carbon source in the growth medium and heavy water (D20) as the solvent. NMR and mass spectrometry analysis demonstrated the complete deuteration of the non-exchangeable protons in the extracted chitosan molecule. Further tuning of the level of deuteration may be achieved by changing the H/D content in the growth medium. Apart from limited reports of partially deuterated chitosan through functional groups or exchangeable protons using deuterated solvent, there are no examples of biosynthesised deuterated chitosan in the literature. This capability, developed at the National Deuteration Facility, ANSTO, provides a range of possibilities for characterising chitosan materials using isotope-sensitive techniques.

  4. Ex vivo and in vitro synchrotron-based micro-imaging of biocompatible materials applied in dental surgery

    Science.gov (United States)

    Rack, A.; Stiller, M.; Nelson, K.; Knabe, C.; Rack, T.; Zabler, S.; Dalügge, O.; Riesemeier, H.; Cecilia, A.; Goebbels, J.

    2010-09-01

    Biocompatible materials such as porous bioactive calcium phosphate ceramics or titanium are regularly applied in dental surgery: ceramics are used to support the local bone regeneration in a given defect, afterwards titanium implants replace lost teeth. The current gold standard for bone reconstruction in implant dentistry is the use of autogenous bone grafts. But the concept of guided bone regeneration (GBR) has become a predictable and well documented surgical approach using biomaterials (bioactive calcium phosphate ceramics) which qualify as bone substitutes for this kind of application as well. We applied high resolution synchrotron microtomography and subsequent 3d image analysis in order to investigate bone formation and degradation of the bone substitute material in a three-dimensional manner, extending the knowledge beyond the limits of classical histology. Following the bone regeneration, titanium-based implants to replace lost teeth call for high mechanical precision, especially when two-piece concepts are used in order to guaranty leak tightness. Here, synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in these kind of highly attenuating objects. Therefore, we could study micro-gap formation at interfaces in two-piece dental implants with the specimen under different mechanical load. We could prove the existence of micro-gaps for implants with conical connections as well as to study the micromechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential issue of failure, i. e. bacterial leakage which can induce an inflammatory process.

  5. Phase III study on surface construction and biocompatibility of polymer materials as cardiovascular devices:coagulant and anti-coagulant surface modification

    Institute of Scientific and Technical Information of China (English)

    Chen Bao-lin; Wang Dong-an

    2015-01-01

    BACKGROUND: As the cardiovascular device, biomaterials applied under the blood-contact conditions should have anti-thrombotic, anti-biodegradable and anti-infective properties. OBJECTIVE: To develop novel polymer materials for implantation and intervention in cardiovascular tissue engineering and to explore the biocompatibility, blood compatibility and cytocompatibility of the surface-modified polymer biomaterials based on the coagulant and anti-coagulant coating modification. METHODS:We retrieved PubMed and WanFang databases for relevant articles publishing from 1983 to 2014. The key words were "biocompatibility, blood compatibility, biomedical materials, biomedical polymer materials" in English and Chinese, respectively. Those unrelated, outdated and repetitive papers were excluded. Literatures addressing the blood compatibility of biomedical polymer materials were summarized. RESULTS AND CONCLUSION: The blood-implant interaction and the anti-coagulant surface modification of biomaterials were analyzed. The biocompatibility, blood compatibility and cytocompatibility of the surface-modified polymer biomaterials were determined based on the coagulant and anti-coagulant coating modification. The coagulant and anti-coagulant surface modification of polymer biomaterials and the research on their biocompatibility and endothelial cel compatibility are crucial for developing novel polymer materials for implantation and intervention in cardiovascular tissue engineering. Through in-depth studies of the types and applications of polymer biomaterials, cardiovascular medical devices and implantable soft tissue substitutes, the differences between the surface and the body wil be reflected in the many layers of molecules extending from the surface to the body. Two major factors, surface energy and molecular mobility, determine the body/surface behaviors that include body/surface differences and phase separation. Considering the difference between the body/surface composition

  6. [In Situ Polymerization and Characterization of Hydroxyapatite/polyurethane Implanted Material].

    Science.gov (United States)

    Gu, Muqing; Xiao, Fengjuan; Liang, Ye; Yue, Lin; Li, Song; Li, Lanlan; Feng, Feifei

    2015-08-01

    In order to improve the interfacial bonding strength of hydroxyapatite/polyurethane implanted material and dispersion of hydroxyapatite in the polyurethane matrix, we in the present study synthesized nano-hydroxyapatite/polyurethane composites by in situ polymerization. We then characterized and analyzed the fracture morphology, thermal stability, glass transition temperature and mechanical properties. We seeded MG63 cells on composites to evaluate the cytocompatibility of the composites. In situ polymerization could improve the interfacial bonding strength, ameliorate dispersion of hydroxyapatite in the properties of the composites. After adding 20 wt% hydroxyapatite into the polyurethane, the thermal stability was improved and the glass transition temperatures were increased. The tensile strength and maximum elongation were 6.83 MPa and 861.17%, respectively. Compared with those of pure polyurethane the tensile strength and maximum elongation increased by 236.45% and 143.30%, respectively. The composites were helpful for cell adhesion and proliferation in cultivation. PMID:26710455

  7. The Interaction of Bacteria with Engineered Nanostructured Polymeric Materials: A Review

    Directory of Open Access Journals (Sweden)

    Ilaria Armentano

    2014-01-01

    Full Text Available Bacterial infections are a leading cause of morbidity and mortality worldwide. In spite of great advances in biomaterials research and development, a significant proportion of medical devices undergo bacterial colonization and become the target of an implant-related infection. We present a review of the two major classes of antibacterial nanostructured materials: polymeric nanocomposites and surface-engineered materials. The paper describes antibacterial effects due to the induced material properties, along with the principles of bacterial adhesion and the biofilm formation process. Methods for antimicrobial modifications of polymers using a nanocomposite approach as well as surface modification procedures are surveyed and discussed, followed by a concise examination of techniques used in estimating bacteria/material interactions. Finally, we present an outline of future sceneries and perspectives on antibacterial applications of nanostructured materials to resist or counteract implant infections.

  8. Biocompatibility of composite resins

    OpenAIRE

    Sayed Mostafa Mousavinasab

    2011-01-01

    Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concern...

  9. Luminescent properties of hybrid materials prepared by the polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Larissa H., E-mail: larissahelena2009@gmail.com [LIEC-UNESP, Institute of Chemistry, Caixa Postal 355, 14800-900 Araraquara, SP (Brazil); Moura, Ana Paula de; Longo, Elson; Varela, José A. [LIEC-UNESP, Institute of Chemistry, Caixa Postal 355, 14800-900 Araraquara, SP (Brazil); Rosa, Ieda L.V. [LIEC-UFSCar, Department of Chemistry, Caixa Postal 676, 13560-905 São Carlos, SP (Brazil)

    2013-12-05

    Highlights: •The Eu{sup 3+} ions are chelating to the 2-hydroxynicotinic acid via O,O-coordination. •A Class II hybrid material was formed by increasing the temperature to 300 °C. •The 2-hydroxynicotinic acid insert in a silica matrix became thermally stable. •PL emission showed a charge transference from 2-hydroxynicotinic to Eu{sup 3+} ions. -- Abstract: Rare earth complexes (RE) can be incorporated in silica matrixes, originating organic/inorganic hybrid materials with good thermal stability and high rare earth emission lines. In this work, the hybrid material was obtained by the polymeric precursor method and ultrasonic dispersed with spherical silica particles prepared by the Stöber Method. The Raman spectra indicated that the Eu{sup 3+} ions are involved in a polymeric structure formed as consequence of the chelation and polyesterification reactions of this ion with citric acid and ethylene glycol. After the ultrasonic stirring, 2-hydroxynicotinic ligand will also compose this polymeric rigid structure. The TGA/DTA analysis showed that this polymeric material was thermal decomposed at 300 °C. Moreover, this process allows the chelating process of the 2-hydroxynicotinic acid ligand to the Eu{sup 3+} ions. The {sup 29}Si NMR showed that the ultrasonic dispersion of the reactants was not able to promote the functionalization of the silica particles with the 2-hydroxynicotinic acid ligand. Moreover, heat treatment promotes the [Eu(HnicO{sub 2}){sub 3}] complex particles incorporation into silica pores. At this temperature, the TGA curve showed that only the thermal degradation of ethylene glycol and citric acid used during the experimental procedure occurs. The silica and hybrid materials are composed by spherical and aggregated particles with particle size of approximately 450 nm, which can be influenced by the heat treatment. These materials also present an absorption band located at 337 nm. The photoluminescent study showed that when the hybrid

  10. Characterization of plasmas and plasma treated polymeric material surfaces for adhesion improvement

    Energy Technology Data Exchange (ETDEWEB)

    Kusano, Y.; Teodoru, S.; Leipold, F.; Michelsen, P.K. (Technical Univ. of Denmark, Optics and Plasma Research Dept., Roskilde (Denmark)); Rozlosnik, N. (Risoe DTU, Materials Research Dept., Roskilde (Denmark)); Soerensen, B.F.; Andersen, T.L.; Goutianos, S. (Technical Univ. of Denmark, Dept. of Micro- and Nanotechnology, Roskilde (Denmark))

    2008-10-15

    Polymeric materials are widely used in a variety of applications, but adhesion to these materials is often difficult because of their low surface energy and poor chemical reactivity. Therefore improving the adhesion to polymeric materials is of considerable importance in assembly of mechanical structures and composite materials. Plasma treatment, which can be operated at room temperature, is attractive for this purpose because they avoid the use of solvents and toxic chemicals, and only the surface is efficiently treated while the bulk properties remain unchanged. With the aim of adhesion improvement, glassy carbon plates, carbon fibres and glass fibre reinforced polyester (GFRP) plates were treated using atmospheric pressure plasmas chosen from a dielectric barrier discharge (DBD) and gliding arcs. Optical emission spectroscopy (OES) of the plasma indicates that oxygen or nitrogen containing radicals were generated, suggesting that they could react at the exposed surfaces during the treatment. Surface characterization using contact angle measurement and x-ray photoelectron spectroscopy (XPS) indicates that after plasma treatment the polar component of surface energy increased and oxygen-containing polar functional groups were effectively introduced onto the surfaces. Raman spectroscopic observation of glassy carbon plates suggests that the defect density, hardness, and density at the surfaces increased with the treatment. Atomic force microscopy indicates that surface roughness tends to increase after the treatment. These characterizations were used for understanding of surface modification effect for observed adhesion improvement. (au)

  11. Studies on Stress-Strain Relationships of Polymeric Materials Used in Space Applications

    Science.gov (United States)

    Jana, Sadhan C.; Freed, Alan

    2002-01-01

    A two-year research plan was undertaken in association with Polymers Branch, NASA Glenn Research Center, to carry out experimental and modeling work relating stress and strain behavior of polymeric materials, especially elastomers and vulcanized rubber. An experimental system based on MTS (Mechanical Testing and Simulation) A/T-4 test facility environment has been developed for a broader range of polymeric materials in addition to a design of laser compatible temperature control chamber for online measurements of various strains. Necessary material processing has been accomplished including rubber compounding and thermoplastic elastomer processing via injection molding. A broad suite of testing methodologies has been identified to reveal the complex non-linear mechanical behaviors of rubbery materials when subjected to complex modes of deformation. This suite of tests required the conceptualization, design and development of new specimen geometries, test fixtures, and test systems including development of a new laser based technique to measure large multi-axial deformations. Test data has been generated for some of these new fixtures and has revealed some complex coupling effects generated during multi-axial deformations. In addition, fundamental research has been conducted concerning the foundation principles of rubber thermodynamics and resulting theories of rubber elasticity. Studies have been completed on morphological properties of several thermoplastic elastomers. Finally, a series of steps have been identified to further advance the goals of NASA's ongoing effort.

  12. Accelerated Aging Effect on Epoxy-polysiloxane Polymeric Insulator Material with Rice Husk Ash Filler

    Directory of Open Access Journals (Sweden)

    Rochmadi .

    2012-08-01

    Full Text Available The performances of outdoor polymeric insulators are influenced by environmental conditions. This paper presents the effect of artificial tropical climate on the hydrophobicity, equivalent salt deposit density (ESDD, surface leakage current, flashover voltage, and surface degradation on epoxy-polysiloxane polymeric insulator materials with rice husk ash (RHA. Test samples are made at room temperature vulcanized (RTV of various composition of epoxy-polysiloxane with rice husk ash as filler. The aging was carried out in test chamber at temperature from 50oC to 62oC, relative humidity of 60% to 80%, and ultraviolet (UV  radiation 21.28 w/cm2 in daylight conditions for 96 hours. The experiment results showed that the flashover voltage fluctuates from 34.13 kV up to 40.92 kV and tends to decrease on each variation of material composition. The surface leakage current fluctuates and tends to increase. Test samples with higher filler content result greater hydrophobicity, smaller equivalent salt deposit density, and smaller critical leakage current, which caused the increase of the flashover voltage. Insulator material (RTVEP3 showed the best performance in tropical climate environment. Artificial tropical aging for short duration gives less effect to the surface degradation of epoxy-polysiloxane insulator material.

  13. Techniques used for limiting degradation products of polymeric materials for use in the space environment

    Science.gov (United States)

    Vest, C. E.; Park, J. J.

    1978-01-01

    Techniques are discussed for limiting or controlling the degradation products (outgassing) of polymeric materials in the space environment. One technique, now ASTM E-595-77, is used to screen out those materials which lose greater than 1% Total Mass Loss when in vacuum for 24 hours at 125 C and which have more than 0.10% Collected Volatile Condensable Materials condensing on a collector surface at 25 C. Examples of silicone materials which are high and low in outgassing are given. The numerous mechanical motions in spacecraft experiments require liquid lubricants which also might degrade in space. Labyrinth seals and barrier films are utilized to limit the degradation of or from these lubricants. A recoverable in-flight experiment has been proposed for making definitive measurements of how effective these techniques are in limiting the amounts and escape paths of outgassed molecules.

  14. Influences of air pollutants on polymeric materials. Natural weathering of polymers

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, T.F.R. [Fraunhofer-Institut fuer Chemische Technologie, Pfinztal-Berghausen (Germany)

    1995-12-31

    Polymeric materials are affected during their entire service life by a number of environmental influences. These originate from both man made and natural sources. Such environmental influences include solar radiation, temperature, humidity and air pollutant effects. They all act together, some independently and some synergistically, to influence material properties, as well as functionality, service life, quality and reliability of the poly materials and systems. The main degradation process is chain scission with loss of molecular weight and oxidation, followed by fading of colours and loss of gloss and mechanical strength. Due to the large number of different types of polymers there are many types of degradation processes and it is difficult to generalise about the effects of the environment on organic materials. Materials, as opposed to organisms, have no self-repair mechanism which allows them to tolerate a certain level of stress. In principle, therefore, it is not possible to define critical levels for the effects of pollutants on materials below which no deterioration occurs. Material deterioration by weathering is normally a very slow process lasting some or more years. Therefore attempts have been made to produce deterioration in short-term experiments by using high stress levels. The limits for the high stress levels are given by the comparability of the obtained damage from artificially accelerated weathering with these from real natural weathering. To investigate the damage caused by air pollutants on polymeric materials, samples were natural weathered with some light exposed and some dark stored samples in different climatic and polluted areas of Germany. The weathering stations are closed to the continuously measuring stations for air quality

  15. Analisa Sifat Fisis Dan Koefisien Serap Bunyi Material Komposit Polymeric Foam Dengan Variabel Polyurethane Untuk Pembuatan Badan Pesawat Uav

    OpenAIRE

    Dinata, Frans

    2014-01-01

    Acoustic material is a material engineering whose main function is to absorb the sound. Acoustic material is a material that can absorb sound energy, but the amount of absorbed energy is different for each material. The general objective of this research is to analyze the physical properties and sound absorption coefficient of composite polymeric foam material reinforced by palm trunk fiber to be used on airframe. From this research found that the variable II has a good physical properties an...

  16. 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

  17. Influence of the polymer amount on bioactivity and biocompatibility of SiO2/PEG hybrid materials synthesized by sol–gel technique

    International Nuclear Information System (INIS)

    SiO2/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 (SiO2 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 SiO2/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: • SiO2/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 • Biocompatibility improvement with

  18. Charge transfer dynamics from organometal halide perovskite to polymeric hole transport materials in hybrid solar cells

    OpenAIRE

    Brauer, Jan C.; Lee, Yong Hui; Nazeeruddin, Mohammad Khaja; Banerji, Natalie

    2016-01-01

    Organometal halide perovskites have emerged as promising next-generation solar cell technologies presenting outstanding efficiencies. However, many questions concerning their working principles remain to be answered. Here, we present a detailed study of hole transfer dynamics into polymeric hole transporting materials (HTMs), poly(triarylamine) (PTAA), poly(3-hexylthiophee-2,5-diyl (P3HT), and poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiaz...

  19. Surface modification of polymeric materials and its effect on blood compatibility

    International Nuclear Information System (INIS)

    This paper reports the surfaces of commercially available polymeric materials modified through two techniques, the chemical infusion process and physical vapor deposition. The surfaces of poly(methylmethacrylate) (PMMA) have been modified through a chemical infusion process by treatment of the sample with a solution containing varying amounts of titanium (IV) isopropoxide and polyvinylpyrrolidone (PVP). The surfaces of silicone rubber samples have been coated with a thin coating of titanium dioxide with an ion beam sputtering technique. The treated samples were characterized by scanning electron microscopy, optical microscopy, and neutron activation analysis

  20. Design, synthesis and polymerization of novel second-order nonlinear optical materials

    Science.gov (United States)

    Ghosn, Rima Kamal

    1997-10-01

    This dissertation focuses on the design, synthesis and nonlinear optical properties of large second-order nonlinearity chromophores. A review of the fundamentals of nonlinear optics and polymeric materials is provided in the first chapter. The second chapter focuses on the optimization of reaction conditions of asymmetric diphenyl diacetylene liquid crystals. The third chapter deals with the design and synthesis of chromophores derived from thiobarbituric acids. Conventional nonlinear optical organic materials employ chromophores possessing a large transition dipole moment between the ground and first excited states. This requirement is fulfilled using conjugated molecules containing optimally balanced electron donor and acceptor moieties. Barbituric acid is a strong electron acceptor that yields molecules with a large first hyperpolarizabilities. There are two classes of chromophores investigated, both capable of covalent polymer incorporation, which include the main chain and double-end crosslinkable chromophores. These chromophores, high in both nonlinearity and thermal stability, are regarded as ideal candidates for electrooptical devices. The fourth chapter investigates polyimides as stable NLO polymeric materials.

  1. Determination of residual monomers resulting from the chemical polymerization process of dental materials

    Energy Technology Data Exchange (ETDEWEB)

    Boboia, S. [Babes Bolyai University, Raluca Ripan Chemistry Research Institute, Department of Polymer Composites, 400294 Cluj-Napoca, Romania and Technical University of Cluj-Napoca, Physics and Chemistry Department, 400114 Cluj-Napoca (Romania); Moldovan, M. [Babes Bolyai University, Raluca Ripan Chemistry Research Institute, Department of Polymer Composites, 400294 Cluj-Napoca (Romania); Ardelean, I. [Technical University of Cluj-Napoca, Physics and Chemistry Department, 400114 Cluj-Napoca (Romania)

    2013-11-13

    The residual monomer present in post-polymerized dental materials encourages premature degradation of the reconstructed tooth. That is why the residual monomer should be quantified in a simple, fast, accurate and reproducible manner. In our work we propose such an approach for accurate determination of the residual monomer in dental materials which is based on low-field nuclear magnetic resonance (NMR) relaxometry. The results of the NMR approach are compared with those of the high performance liquid chromatography (HPLC) technique. The samples under study contain the main monomers (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane and triethylene glycol dimethacrylate) constituting the liquid phase of most dental materials and an initiator. Two samples were analyzed with different ratios of chemical initiation systems: N,N-dimethyl-p-toluide: benzoyl peroxide (1:2 and 0.7:1.2). The results obtained by both techniques highlight that by reducing the initiator the polymerization process slows down and the amount of residual monomer reduces. This prevents the premature degradation of the dental fillings and consequently the reduction of the biomaterial resistance.

  2. Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); El-Rashidy, Zenab M. [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); Salama, Aida A. [Biophysics Dept., Faulty of Science, El-Azhar Univ., Cairo (Egypt)

    2011-10-17

    Highlights: {yields} The formation and coating of CHA increased by increasing polymer content. {yields} The size of the prepared CHA was within nano-range scale. {yields} The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

  3. Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

    International Nuclear Information System (INIS)

    Highlights: → The formation and coating of CHA increased by increasing polymer content. → The size of the prepared CHA was within nano-range scale. → The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

  4. Determination of residual monomers resulting from the chemical polymerization process of dental materials

    International Nuclear Information System (INIS)

    The residual monomer present in post-polymerized dental materials encourages premature degradation of the reconstructed tooth. That is why the residual monomer should be quantified in a simple, fast, accurate and reproducible manner. In our work we propose such an approach for accurate determination of the residual monomer in dental materials which is based on low-field nuclear magnetic resonance (NMR) relaxometry. The results of the NMR approach are compared with those of the high performance liquid chromatography (HPLC) technique. The samples under study contain the main monomers (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane and triethylene glycol dimethacrylate) constituting the liquid phase of most dental materials and an initiator. Two samples were analyzed with different ratios of chemical initiation systems: N,N-dimethyl-p-toluide: benzoyl peroxide (1:2 and 0.7:1.2). The results obtained by both techniques highlight that by reducing the initiator the polymerization process slows down and the amount of residual monomer reduces. This prevents the premature degradation of the dental fillings and consequently the reduction of the biomaterial resistance

  5. Standard Practice for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering Structural Applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice covers the procedures for computing characteristic values of material properties of polymeric composite materials intended for use in civil engineering structural applications. The characteristic value is a statistically-based material property representing the 80 % lower confidence bound on the 5th-percentile value of a specified population. Characteristic values determined using this standard practice can be used to calculate structural member resistance values in design codes for composite civil engineering structures and for establishing limits upon which qualification and acceptance criteria can be based. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. An Overview of Polymeric Materials for Propellant Tank Membrane Applications in Europe

    Science.gov (United States)

    Valencia Bel, F.; Caramelli, F.

    2004-10-01

    Diaphragms and bladders are used as positive expulsion devices in liquid propulsion systems since the early stages of space flight. This paper presents an identification of the critical properties of polymeric materials for positive expulsion systems and an overview of the applicable mechanical and chemical performance requirements identified and tested in the frame of ESA technology development initiatives either carried out as R&D activities or within specific hardware development programs for Spacecraft projects. A set of requirements based on those experiences is presented. Finally, an approach of modelling and a comparison with experimental results is proposed for the identified critical properties. Materials currently adopted or considered suitable for potential utilisation in Monopropellant (Hydrazine) and Bipropellant systems (UDMH-NTO) have been treated. Possible alternative materials have also been described to provide a wider view of potential technological solutions.

  7. Characterization and modeling of ionic polymeric smart materials as artificial muscles and robotic swimming structures

    Science.gov (United States)

    Mojarrad, Mehran

    2001-07-01

    In this dissertation document, a thorough review and investigation of works in connection with the ionic polymeric gels as artificial muscles and electrically controllable polymeric network structures were performed. Where possible, comparisons were made with biological muscles and applications in marine propulsion using such polymeric materials were investigated. Furthermore, methods of fabrication of several chemically active ionic polymeric gel muscles such as PolyAcryloNitrile (PAN), Poly(2-Acrylamido-2-Methyl-1-PropaneSulfonic) acid (PAMPS), and PolyAcrylic-acid-bis-AcrylaMide (PAAM) as well as a new class of electrically active composite muscle such as Ion-Exchange-Metal-Composites (IEMC) or Ionic Polymer Metal Composites (IPMC) materials are introduced and investigated that resulted in two US patents regarding their fabrication and application capabilities as actuators and sensors. In this research, various forms of the IPMC fabrication were explored and reported. In addition, characterization of PAN muscles, bundling and encapsulation were investigated. Conversion of chemical to electrical artificial muscles were also investigated using chemical plating techniques as well as physical vapor deposition methods of the pH-activated muscles like PAN fibers. Experimental methods were devised to characterize contraction, expansion, and bending of various actuators using isometric, isoionic, and isotonic characterization methods. Several apparatuses for modeling and testing of the various artificial muscles were built to show the viability of the application of both chemoactive and electroactive muscles. Furthermore PAN fiber muscles in different configurations such as spring-loaded fiber bundles, biceps, triceps, ribbon type muscles, and segmented fiber bundles were fabricated to make a variety of actuators. Additionally, swimming robotic structures and associated hardware were built to incorporate IPMC as biomimetic propulsion fin actuators. In addition, various

  8. Biocompatibility of Dental Amalgams

    OpenAIRE

    Yurdanur Uçar; Brantley, William A.

    2011-01-01

    Objective. The purpose of this review paper is to review the literature regarding the toxicology of mercury from dental amalgam and evaluate current statements on dental amalgam. Materials and Methods. Two key-words “dental amalgam” and “toxicity” were used to search publications on dental amalgam biocompatibility published in peer-reviewed journals written in English. Manual search was also conducted. The most recent declarations and statements were evaluated using information available on ...

  9. Designing materials for advanced microelectronic patterning applications using controlled polymerization RAFT technology

    Science.gov (United States)

    Sheehan, Michael T.; Farnham, William B.; Chambers, Charles R.; Tran, Hoang V.; Okazaki, Hiroshi; Brun, Yefim; Romberger, Matthew L.; Sounik, James R.

    2011-04-01

    Reversible Addition Fragmentation Chain Transfer (RAFT) polymerization technology enables the production of polymers possessing low polydispersity (PD) in high yield for many applications. RAFT technology also enables control over polymer architecture. With synthetic control over these polymer characteristics, a variety of polymers can be designed and manufactured for use in advanced electronic applications. By matching the specific RAFT reagent and monomer combinations, we can accommodate monomer reactivity and optimize acrylate or methacrylate polymerizations (193 and 193i photoresist polymers) or optimize styrenic monomer systems (248 nm photoresist polymers) to yield polymers with PD as low as 1.05. For 193i lithography, we have used RAFT technology to produce block copolymers comprising of a random "resist" block with composition and size based on conventional dry photoresist materials and a "low surface energy" block The relative block lengths and compositions may be varied to tune solution migration behavior, surface energy, contact angles, and solubility in developer. Directed self assembly is proving to be an interesting and innovative method to make 2- and even 3-dimensional periodic, uniform patterns. Two keys to acceptable performance of directed self assembly from block copolymers are the uniformity and the purity of the materials will be discussed.

  10. Effects of energetic proton bombardment on polymeric materials: experimental studies and degradation models

    International Nuclear Information System (INIS)

    This report describes 3 MeV proton bombardment experiments on several polymeric materials of interest to NASA carried out on the Tandem Van De Graff Accelerator at the California Institute of Technology's Kellogg Radiation Laboratory. Model aromatic and aliphatic polymers such as poly(1-vinyl naphthalene) and poly(methyl methacrylate), as well as polymers for near term space applications such as Kapton, Epoxy and Polysulfone, have been included in this study. Chemical and physical characterization of the damage products have been carried out in order to develop a model of the interaction of these polymers with the incident proton beam. The proton bombardment methodology developed at the Jet Propulsion Laboratory and reported here is part of an ongoing study on the effects of space radiation on polymeric materials. The report is intended to provide an overview of the mechanistic, as well as the technical and experimental, issues involved in such work rather than to serve as an exhaustive description of all the results

  11. A new specific polymeric material for mercury speciation: Application to environmental and food samples.

    Science.gov (United States)

    Zarco-Fernández, S; Mancheño, M J; Muñoz-Olivas, R; Cámara, C

    2015-10-15

    A new polymeric material (Patent: P201400535) highly specific for mercury is presented. Its great capability to pre-concentrate and selectively elute inorganic mercury and methylmercury are the main figures of merit. The polymer can be reused several times. To our knowledge, this is the only polymer proposed in the literature for direct inorganic mercury and methylmercury speciation without need of chromatography or quantification by difference. The polymer formation is based on the reaction of a vinyl derivative of 8-hydroxiquinoline as monomer, and 2-(Methacryloylamino) ethyl 2-Methyl Acrylate (NOBE) as co-monomer. Random radical polymerization by the precipitation method was carried out using Azobisisobutyronitrile (AIBN) as initiator. The polymer was characterized by SEM and FTIR. Adsorption binding isotherms were evaluated using Langmuir and Freundlich models, showing high adsorption capacity for both inorganic and organic mercury species. The polymer was employed to sequentially determine inorganic mercury and methylmercury, using a solid phase extraction (SPE) scheme. Cross reactivity of several ions, as well as matrix effects from a high saline matrix like seawater was irrelevant as the retained fractions mostly eluted during the washing step. The procedure was first validated by analyzing a certified reference material (BCR 464) and finally applied to commercial fish samples. The speciation proposed procedure is cheap, fast, and easy to use and minimizes reagents waste. PMID:26515012

  12. Creep in Photovoltaic Modules: Examining the Stability of Polymeric Materials and Components

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Kempe, M. D.; Glick, S. H.; Kurtz, S. R.

    2011-02-01

    Interest in renewable energy has motivated the implementation of new polymeric materials in photovoltaic modules. Some of these are non-cross-linked thermoplastics, in which there is a potential for new behaviors to occur, including phase transformation and visco-elastic flow. Differential scanning calorimetry and rheometry data were obtained and then combined with existing site-specific time-temperature information in a theoretical analysis to estimate the displacement expected to occur during module service life. The analysis identified that, depending on the installation location, module configuration and/or mounting configuration, some of the thermoplastics are expected to undergo unacceptable physical displacement. While the examples here focus on encapsulation materials, the concerns apply equally to the frame, junction-box, and mounting-adhesive technologies.

  13. The reaction efficiency of thermal energy oxygen atoms with polymeric materials

    Science.gov (United States)

    Koontz, S. L.; Nordine, Paul

    1990-01-01

    The reaction efficiency of several polymeric materials with thermal-energy (0.04 eV translational energy), ground-state (O3P) oxygen atoms was determined by exposing the materials to a room temperature gas containing a known concentration of atomic oxygen. The reaction efficiency measurements were conducted in two flowing afterglow systems of different configuration. Atomic oxygen concentration measurements, flow, transport and surface dose analysis is presented in this paper. The measured reaction efficiencies of Kapton, Mylar, polyethylene, D4-polyethylene and Tedlar are .001 to .0001 those determined with high-energy ground-state oxygen atoms in low earth orbit or in a high-velocity atom beam. D4-polyethylene exhibits a large kinetic isotope effect with atomic oxygen at thermal but not hyperthermal atom energies.

  14. The Effect of Plasma Surface Treatment on a Porous Green Ceramic Film with Polymeric Binder Materials

    Science.gov (United States)

    Jeong, Woo Yun

    2013-06-01

    To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process. The adhesion strength in the lamination films was enhanced by oxidative plasma treatment of the porous green ceramic film with polymeric binding materials. The oxygen plasma characteristics were investigated through experimental parameters and weight loss analysis. The experimental results revealed the need for parameter analysis, including gas material, process time, flow rate, and discharge power, and supported a mechanism consisting of competing ablation and deposition processes. The weight loss analysis was conducted for cyclic plasma treatment rather than continuous plasma treatment for the purpose of improving the film's permeability by suppressing deposition of the ablated species. The cyclic plasma treatment improved the permeability compared to the continuous plasma treatment.

  15. The Effect of Plasma Surface Treatment on a Porous Green Ceramic Film with Polymeric Binder Materials

    International Nuclear Information System (INIS)

    To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process. The adhesion strength in the lamination films was enhanced by oxidative plasma treatment of the porous green ceramic film with polymeric binding materials. The oxygen plasma characteristics were investigated through experimental parameters and weight loss analysis. The experimental results revealed the need for parameter analysis, including gas material, process time, flow rate, and discharge power, and supported a mechanism consisting of competing ablation and deposition processes. The weight loss analysis was conducted for cyclic plasma treatment rather than continuous plasma treatment for the purpose of improving the film's permeability by suppressing deposition of the ablated species. The cyclic plasma treatment improved the permeability compared to the continuous plasma treatment.

  16. Electrospinning of Biodegradable and Biocompatible Nanofiber Patches from Solutions of ``Green'' Materials for Plant Protection against Fungi Attack

    Science.gov (United States)

    Sett, Soumyadip; Lee, Minwook; Yarin, Alexander; Moghadam, S. M. Alavi; Meinke, Matthias; Schroeder, Wolfgang

    2015-11-01

    Biodegradable and biocompatible soy protein/petroleum-derived polymer monolithic fibers containing adhesives were electrospun on commercial rayon pads. The polymers used, PVA and PCL, are widely used in the biomedical industry, including such applications as drug delivery and scaffold manufacturing. Soy protein is an abundant waste of SoyDiesel production, and is widely used as a nutrient. The soy content in our fibers was as high as 40% w/w. Four different adhesives, including ordinary wood glue, repositionable glue and FDA-approved pressure-sensitive glue were used for electrospinning and electrospraying. The normal and shear adhesive strengths of the patches developed in this work were measured and compared. The adhesive strength was sufficient enough to withstand normal atmospheric conditions. These biodegradable and biocompatible nano-textured patches are ready to be used on prune locations without being carried away by wind and will protect plants against fungi attack at these locations, preventing diseases like Vine Decline.

  17. Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell Membranes

    Science.gov (United States)

    Narayan, Sri R.; Yen, Shiao-Ping S.; Reddy, Prakash V.; Nair, Nanditha

    2012-01-01

    Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrene-based quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells. Imidazolium salts are known to be electrochemically stable over wide potential ranges. By controlling the relative ratio of imidazolium groups in polystyrene-imidazolium salts, their physiochemical properties could be modulated. Alkaline anion exchange membranes based on polystyrene-imidazolium hydroxide materials have been developed. The first step was to synthesize the poly(styrene-co-(1-((4-vinyl)methyl)-3- methylimidazolium) chloride through a free-radical polymerization. Casting of this material followed by in situ treatment of the membranes with sodium hydroxide solutions provided the corresponding hydroxide salts. Various ratios of the monomers 4-chloromoethylvinylbenzine (CMVB) and vinylbenzine (VB) provided various compositions of the polymer. The preferred material, due to the relative ease of casting the film, and its relatively low hygroscopic nature, was a 2:1 ratio of CMVB to VB. Testing confirmed that at room temperature, the new membranes outperformed commercially available membranes by a large margin. With fuel cells now in use at NASA and in transportation, and with defense potential, any improvement to fuel cell efficiency is a significant development.

  18. Flavonoids as Natural Stabilizers and Color Indicators of Ageing for Polymeric Materials

    Directory of Open Access Journals (Sweden)

    Anna Masek

    2015-06-01

    Full Text Available Few changes have occurred in the use of various stabilizers over recent years. In the current literature, phosphate derivatives are used as anti-ageing additives in polymers, and the most popular of these are sterically hindering cyclic amines. However, most of these compounds are carcinogenic. Synthetic phenols have been increasingly used as antioxidants in food and in polymers. Ecological standards encourage the elimination of harmful additives in polymeric products that come in contact with food or with the human body. This article presents application of flavonoid (silymarin/flavonoligand for polymer stabilization and use of natural phytocompounds such as color indicators of polymers ageing time. In this research, I propose two ways of application: traditional, during processing; and the new one, by using impregnation method. Based on the change of deformation energy (ageing coefficient K, FTIR, oxidative induction time (OIT evaluated by differential scanning calorimetry (OIT, thermogravimetry analysis (TG, spectrophotometric color measurements in terms of CIE-Lab color space values, I confirmed the high antioxidant activity of flavonoids in EPM. They provide coloration of the polymeric materials that changes cyclically as a function of aging time. Additionally, the use of phytocompounds in polymers provides similar stabilizing effect to those of synthetic antioxidants.

  19. Radiation Protection Effectiveness of Polymeric Based Shielding Materials at Low Earth Orbit

    Science.gov (United States)

    Badavi, Francis F.; Stewart-Sloan, Charlotte R.; Wilson, John W.; Adams, Daniel O.

    2008-01-01

    Correlations of limited ionizing radiation measurements onboard the Space Transportation System (STS; shuttle) and the International Space Station (ISS) with numerical simulations of charged particle transport through spacecraft structure have indicated that usage of hydrogen rich polymeric materials improves the radiation shielding performance of space structures as compared to the traditionally used aluminum alloys. We discuss herein the radiation shielding correlations between measurements on board STS-81 (Atlantis, 1997) using four polyethylene (PE) spheres of varying radii, and STS-89 (Endeavour, 1998) using aluminum alloy spheres; with numerical simulations of charged particle transport using the Langley Research Center (LaRC)-developed High charge (Z) and Energy TRaNsport (HZETRN) algorithm. In the simulations, the Galactic Cosmic Ray (GCR) component of the ionizing radiation environment at Low Earth Orbit (LEO) covering ions in the 1Radiation (AIR) measurements. With the validity of numerical simulations through correlation with PE and aluminum spheres measurements established, we further present results from the expansion of the simulations through the selection of high hydrogen content commercially available polymeric constituents such as PE foam core and Spectra fiber(Registered TradeMark) composite face sheet to assess their radiation shield properties as compared to generic PE.

  20. Proton conducting polymeric materials for hydrogen based electrochemical energy conversion technologies

    DEFF Research Database (Denmark)

    Aili, David

    to the strong plasticizing effect of the dopant. Consequently, the doping level of the membrane has to be a compromise between sufficient mechanical strength for the MEA preparation and maximized proton conductivity. In this work, PBI membranes were crosslinked, either by posttreatment with divinylsulfone...... and electrode separator in both PEM fuel cells and water electrolyzers. The proton conductivity mechanism of Nafion® is strongly dependent on the presence of water within the membrane nanostructure, which limits the operating temperature to about 80 °C unless the system is pressurized in order to keep...... is operated in electrolysis mode since it results in a decreased thermodynamic energy requirement for the water splitting reaction. The aiming for an elevated operating temperature has thus resulted in an increasing demand for novel anhydrous proton conducting polymeric materials for both PEM fuel cells...

  1. Method of polymerizing ethylenically unsaturated materials by irradiation and composition for use therein

    International Nuclear Information System (INIS)

    This patent concerns photopolymerizable compositions consisting essentially of at least one polymerizable ethylenically unsaturated material and a photosensitive catalyst comprising (a) from 0.5 to 5 percent based on the ethylenically unsaturated material of at least one photosensitizer having the structure Ph(CO)C2A(CO)Ph, where Ph is phenyl, halogen-substituted phenyl, phenylene or halogen-substituted phenylene and A is a cyclic hydrocarbyl group, a halogen-substituted cyclic hydrocarbyl group, or a group of the formula X(NR)COCONRY, where X and Y each is hydrogen, a hydrocarbyl, or a halogen-substituted hydrocarbyl group, and (b) from 1 to 5 percent by weight based on the ethylenically unsaturated material of a reducing agent capable of reducing the photosensitizer when the photosensitizer is in an excited state. Also described is a process of preparing polymeric materials by irradiating the foregoing polymerizable composition at a wavelength capable of exciting the photosensitizer to an excited state

  2. STUDY OF POLYMERIC MATERIALS PERFORMANCE IN FRICTION CONDITIONS WITH ICE AND SNOW

    Directory of Open Access Journals (Sweden)

    Shadrinov N. V.

    2015-03-01

    Full Text Available The problem of identifying of the most promising polymer materials for sledge sliding application. The comparison of materials is given: the bench tests of polyethylene, fluoroplast, steel and ultra high molecular weight polyethylene (UHMWPE with different molecular weight and their composites are carried out. On the basis of research of polymeric samples on ice and snow friction in exploiting condition with the use of specially designed sledges was shown that GUR 4150 UHMWPE has the lowest mass volume and linear wear. Also in article the results of research of ice adhesion to different materials are presented. Adhesion research was carried out in low temperature conditions of air from -21oC up to -46oC and in cryocamera according method which was patented by Institute of oil and gas problems of SB RAS. The research showed that GUR 4150 UHMWPE has the lowest adhesion to ice. On the basis of obtained data the authors assumed that GUR 4150 is the most perspective materials for development of sledge sliding exploiting in Arctic conditions.

  3. Predicting emissions of SVOCs from polymeric materials and their interaction with airborne particles.

    Science.gov (United States)

    Xu, Ying; Little, John C

    2006-01-15

    A model that predicts the emission rate of volatile organic compounds (VOCs) from building materials is extended and used to predict the emission rate of semivolatile organic compounds (SVOCs) from polymeric materials. Reasonable agreement between model predictions and gas-phase di-2-ethylhexyl phthalate (DEHP) concentrations is achieved using data collected in a previous experimental study that measured emissions of DEHP from vinyl flooring in two very different chambers. While emissions of highly volatile VOCs are subject to "internal" control (the material-phase diffusion coefficient), emissions of the very low volatility SVOCs are subject to "external" control (partitioning into the gas phase, the convective mass-transfer coefficient, and adsorption onto interior surfaces). The effect of SVOCs partitioning onto airborne particles is also examined. The DEHP emission rate is increased when the gas-phase concentration is high, and especially when partitioning to the airborne particles is strong. Airborne particles may play an important role in inhalation exposure as well as in transporting SVOCs well beyond the source. Although more rigorous validation is needed, the model should help elucidate the mechanisms governing emissions of phthalate plasticizers, brominated flame retardants, biocides, and other SVOCs from a wide range of building materials and consumer products. PMID:16468389

  4. Investigation of metallic, ceramic, and polymeric materials for engineered barrier applications in nuclear-waste packages

    International Nuclear Information System (INIS)

    An effort to develop licensable engineered barrier systems for the long-term (about 1000 yr) containment of nuclear wastes under conditions of deep continental geologic disposal has been underway at Pacific Northwest Laboratory since January 1979, under the auspices of the High-Level Waste Immobilization Program. In the present work, the barrier system comprises the hard or structural elements of the package: the canister, the overpack(s), and the hole sleeve. A number of candidate metallic, ceramic, and polymeric materials were put through mechanical, corrosion, and leaching screening tests to determine their potential usefulness in barrier-system applications. Materials demonstrating adequate properties in the screening tests will be subjected to more detailed property tests, and, eventually, cost/benefit analyses, to determine their ultimate applicability to barrier-system design concepts. The following materials were investigated: two titanium alloys of Grade 2 and Grade 12; 300 and 400 series stainless steels, Inconels, Hastelloy C-276, titanium, Zircoloy, copper-nickel alloys and cast irons; total of 14 ceramic materials, including two grades of alumina, plus graphite and basalt; and polymers such as polyamide-imide, polyarylene, polyimide, polyolefin, polyphenylene sulfide, polysulfone, fluoropolymer, epoxy, furan, silicone, and ethylene-propylene terpolymer (EPDM) rubber. The most promising candidates for further study and potential use in engineered barrier systems were found to be rubber, filled polyphenylene sulfide, fluoropolymer, and furan derivatives

  5. The sorption of selected radionuclides on various metal and polymeric materials

    International Nuclear Information System (INIS)

    Twenty-two various polymeric and metallic materials were evaluated for characteristic sorption properties with respect to selenium-75, strontium-85 and cesium-137 in synthetic ground water. These experiments were conducted to determine which materials would not influence sorption measurements and could be used in the design and fabrication of field apparatus to study radionuclide migration in fractured rock. This paper gives the results of static batch (Ksub(a)) sorption experiments along with details of the laboratory and analytical procedures. Of the materials tested, zirconium metal, Lucite, urethane, polycarbonate, Viton (E-60C) and fluorohydrocarbon (i.e., Teflon FEP and Teflon TFE) were found to show little or no sorption (2) for each of the radionuclides tested. Materials such as Neoprene, steel, Hycar, cold-rolled steel, nitrile and 316-stainless steel showed higher Ksub(a) values (>= 1.0 ml/cm 2) for at least one of radionuclides. Selenium-75 was found to exhibit the greatest overall sorption tendency. (Auth.)

  6. Surface Function alizations of Some Polymeric Materials for Possible Use in Biomedical Applications

    International Nuclear Information System (INIS)

    Grafting vinyl acetate (VAc) and itaconic acid (IA) comonomer onto polyethylene (PE) and polypropylene (PP) was performed by means of gamma rays. Conditions for the minimum homopolymer formation, maximum grafting yield and alternate copolymer grafts were carried out. The swelling and biocompatibility properties of these copolymers were evaluated for possible application in the field of blood biocompatibility as in medical devices, artificial organs and hemodialysis membranes. The grafted membranes on different irradiation dose showed improved swelling and blood biocompatibility. The presence of functional groups on the membranes reduced protein adsorption and enhanced The swelling and protein low affinity properties of PE-g-(VAc-alt-IA) and PP-g- (VAc-alt-IA) indicate potential use as blood biocompatible membranes

  7. Coatings of titanium substrates with xCaO · (1 - x)SiO2 sol-gel materials: characterization, bioactivity and biocompatibility evaluation.

    Science.gov (United States)

    Catauro, M; Papale, F; Bollino, F

    2016-01-01

    The objective of this study has been to develop low temperature sol-gel coatings to modify the surface of commercially pure titanium grade 4 (a material generally used in dental application) and to evaluate their bioactivity and biocompatibility on the substrate. Glasses of composition expressed by the following general formula xCaO · (1 - x)SiO2 (0.0characterized and a microstructural analysis of the coatings obtained was performed using scanning electron microscopy (SEM). The potential applications of the coatings in the biomedical field were evaluated by bioactivity and biocompatibility tests. The coated titanium was immersed in simulated body fluid (SBF) for 21 days and the hydroxyapatite deposition on its surface was subsequently evaluated via SEM-EDXS analysis, as an index of bone-bonding capability. To investigate cell-material interactions, mouse embryonic fibroblast cells (3T3) were seeded onto the specimens and the cell viability was evaluated by a WST-8 assay. PMID:26478379

  8. DNA-nanoparticle assemblies go organic: Macroscopic polymeric materials with nanosized features

    Directory of Open Access Journals (Sweden)

    Mentovich Elad D

    2012-05-01

    Full Text Available Abstract Background One of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materials. This approach can be used for the development of new detection strategies as well as nanoelectronic structures and devices. Method Here we present a new method for the generation of unprecedented all-organic conjugated-polymer nanoparticle networks guided by DNA, based on a hierarchical self-assembly process. First, microphase separation of amphiphilic block copolymers induced the formation of spherical nanoobjects. As a second ordering concept, DNA base pairing has been employed for the controlled spatial definition of the conjugated-polymer particles within the bulk material. These networks offer the flexibility and the diversity of soft polymeric materials. Thus, simple chemical methodologies could be applied in order to tune the network's electrical, optical and mechanical properties. Results and conclusions One- two- and three-dimensional networks have been successfully formed. Common to all morphologies is the integrity of the micelles consisting of DNA block copolymer (DBC, which creates an all-organic engineered network.

  9. Durability of Polymeric Encapsulation Materials for a PMMA/glass Concentrator Photovoltaic System

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C.; Kempe, Michael D.; Muller, Matthew T; Gray, Matthew H.; Araki, Kenji; Kurtz, Sarah R.

    2014-04-08

    The durability of polymeric encapsulation materials was examined using outdoor exposure at the nominal geometric concentration of 500 suns. The results for 36 months cumulative field deployment are presented for materials including: poly(ethylene-co-vinyl acetate), (EVA); polyvinyl butyral (PVB); ionomer; polyethylene/ polyoctene copolymer (PO); thermoplastic polyurethane (TPU); poly(dimethylsiloxane) (PDMS); poly(diphenyl dimethyl siloxane) (PDPDMS); and poly(phenyl-methyl siloxane) (PPMS). Measurements of the field conditions including ambient temperature and ultraviolet (UV) dose were recorded at the test site during the experiment. Measurements for the experiment included optical transmittance (with subsequent analysis of solar-weighted transmittance, UV cut-off wavelength, and yellowness index), mass, visual photography, photoelastic imaging, and fluorescence spectroscopy. While the results to date for EVA are presented and discussed, examination here focuses more on the siloxane materials. A specimen recently observed to fail by thermal decomposition is discussed in terms of the implementation of the experiment as well as its fluorescence signature, which was observed to become more pronounced with age. Modulated thermogravimetry (allowing determination of the activation energy of thermal decomposition) was performed on a subset of the siloxanes to quantify the propensity for decomposition at elevated temperatures. Supplemental, Pt-catalyst- and primer-solutions as well as peroxide-cured PDMS specimens were examined to assess the source of the luminescence. The results of the study including the change in optical transmittance, observed failure modes, and subsequent analyses of the failure modes are described in the conclusions.

  10. Integration of functional materials and surface modification for polymeric microfluidic systems

    International Nuclear Information System (INIS)

    The opportunity for the commercialization of microfluidic systems has surged over the recent decade, primarily for medical and the life science applications. This positive development has been spurred by an increasing number of integrated, highly functional lab-on-a-chip technologies from the research community. Toward commercialization, there is a dire need for economic manufacture which involves optimized cost for materials and structuring on the front-end as well as for a range of back-end processing steps such as surface modification, integration of functional elements, assembly and packaging. Front-end processing can readily resort to very well established polymer mass fabrication schemes, e.g. injection molding. Also assembly and packaging can often be adopted from commercially available processes. In this review, we survey the back-end processes of hybrid material integration and surface modification which often need to be tailored to the specifics of miniaturized polymeric microfluidic systems. On the one hand, the accurate control of these back-end processes proves to be the key to the technical function of the system and thus the value creation. On the other hand, the integration of functional materials constitutes a major cost factor. (topical review)

  11. Design of polymeric capsules for autonomous healing of cracks in cementitious materials

    OpenAIRE

    HILLOULIN, Benoit; Van Tittelboom, Kim; Gruyaert, Elke; LOUKILI, Ahmed; De Belie, Nele

    2013-01-01

    Now, most of the capsules used to contain polymeric healing agents in self-healing concrete, are made of glass. However, glass capsules cannot be mixed in concrete and are therefore placed manually into the moulds during concrete casting in laboratory tests. This represents a major drawback for an eventual industrialisation. In this study, polymeric capsules were designed to meet three requirements: breakage upon crack appearance, compatibility with the polymeric healing agent and survival...

  12. Fiscal 1998 regional consortium R and D project (Regional consortium field). Report on R and D of production technology of hybrid-type biocompatible hard tissue replacing materials (1st fiscal year); 1998 nendo chiiki konsoshiamu kenkyu kaihatsu jigyo. Chiiki konsoshiamu bun'ya (hybrid gata seitai yugo kinosei kososhiki daitai sozai seizo gijutsu no kenkyu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This project aims at development of high-strength high- biocompatible {beta}-type Ti alloy with lower modulli of elasticity composed of non-toxic elements, phosphate calcium ceramics for improving the biocompatibility and coating technology, and establishment of production technology of hybrid-type biocompatible hard tissue replacing materials. In fiscal 1998, the project promoted the following: Design of high-biocompatible {beta}-type Ti alloy materials, development of thermomechanical treatment for improving dynamic characteristics of such alloy, survey on practical melting and casting technologies and dental precision casting process, evaluation of the biocompatibility of the alloy by cytotoxicity, selection of tools for precision machining and surface finishing, control of contents, orientation and precipitation of biocompatible crystals such as {beta}- Ca(PO{sub 3}){sub 2} fibers for further improvement of the biocompatibility. This paper also outlines the survey results on the market needs, market size and market share for the feasibility of these materials. (NEDO)

  13. Investigation of different polymerization methods on the analytical performance of palladium(II) ion imprinted polymer materials

    International Nuclear Information System (INIS)

    Palladium(II) ion imprinted polymer (IIP) materials were prepared via bulk, precipitation and suspension polymerization methods using similar compositions. In these polymerization methods, the polymerization mixture consists of a ternary complex of palladium(II) imprint ion with 8-aminoquinoline (AQ), 4-vinyl pyridine (VP, monomer), 2-hydroxyethyl methacrylate (HEMA, functional monomer), ethylene glycoldimethacrylate (EGDMA, cross-linking monomer), 2,2'-azobisisobutyronitrile (AIBN, initiator) and 2-methoxy ethanol (Porogen). Various polymerization methods were carried out by thermal means and IIP materials thus obtained were leached with 50% (v/v) HCl to obtain leached IIP particles. Control polymer (CP) particles were similarly prepared by all the three polymerization methods. The above synthesized polymer particles were characterized physically and morphologically by using FTIR, TGA, CHN, X-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques. Furthermore, their capacity to rebind palladium(II) was investigated from dilute aqueous solutions and in presence of selected precious and transition elements (which are known to coexist with palladium in its mineral deposits). The rebinding studies of IIP particles obtained via bulk, precipitation and suspension methods reveal that (i) percent enrichment is quantitative with bulk and precipitation, and ∼72% only in case of suspension; (ii) retention capacities are 28.82, 20.16 and 18.76 mg palladium(II)/g materials, respectively; (iii) selectivity for palladium(II) over other noble and transition elements lies in the order bulk ∼ precipitation > emulsion. Moreover, the IIP particles obtained by all three polymerization methods exhibit imprinting effect when compared with respective CP particles

  14. Investigation of different polymerization methods on the analytical performance of palladium(II) ion imprinted polymer materials

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Sobhi [Regional Research Laboratory (CSIR), Trivandrum 695019, Kerala (India); Prabhakara Rao, P. [Regional Research Laboratory (CSIR), Trivandrum 695019, Kerala (India); Prasada Rao, T. [Regional Research Laboratory (CSIR), Trivandrum 695019, Kerala (India)]. E-mail: tprasadarao@rediffmail.com

    2005-04-22

    Palladium(II) ion imprinted polymer (IIP) materials were prepared via bulk, precipitation and suspension polymerization methods using similar compositions. In these polymerization methods, the polymerization mixture consists of a ternary complex of palladium(II) imprint ion with 8-aminoquinoline (AQ), 4-vinyl pyridine (VP, monomer), 2-hydroxyethyl methacrylate (HEMA, functional monomer), ethylene glycoldimethacrylate (EGDMA, cross-linking monomer), 2,2'-azobisisobutyronitrile (AIBN, initiator) and 2-methoxy ethanol (Porogen). Various polymerization methods were carried out by thermal means and IIP materials thus obtained were leached with 50% (v/v) HCl to obtain leached IIP particles. Control polymer (CP) particles were similarly prepared by all the three polymerization methods. The above synthesized polymer particles were characterized physically and morphologically by using FTIR, TGA, CHN, X-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques. Furthermore, their capacity to rebind palladium(II) was investigated from dilute aqueous solutions and in presence of selected precious and transition elements (which are known to coexist with palladium in its mineral deposits). The rebinding studies of IIP particles obtained via bulk, precipitation and suspension methods reveal that (i) percent enrichment is quantitative with bulk and precipitation, and {approx}72% only in case of suspension; (ii) retention capacities are 28.82, 20.16 and 18.76 mg palladium(II)/g materials, respectively; (iii) selectivity for palladium(II) over other noble and transition elements lies in the order bulk {approx} precipitation > emulsion. Moreover, the IIP particles obtained by all three polymerization methods exhibit imprinting effect when compared with respective CP particles.

  15. Physical principles of ion-beam processing of polymeric materials and applications

    International Nuclear Information System (INIS)

    Irradiation of polymeric materials with energetic ions in the range of several hundreds of keV to several MeV causes drastic changes in physical, chemical, and mechanical properties. Studies indicate that irradiation produces many active radicals which then react with each other, transforming spaghetti-like tangled polymer chains into a highly cross-linked network structure. Analysis of experimental data shows that the most important parameter for cross-linking is the deposited energy density along the ion track, often expressed in terms of linear energy transfer (LET) in units of eV/nm. High LET produces a high number of free radicals over many neighboring molecular chains and thereby facilitates cross-linking. On the other hand, under low LET conditions, radicals are produced so sparsely that cross-linking efficiency decreases. Moreover, the deposited energy in the chain often leads to chain scission when there are no radicals in the neighboring chains for crosslinking. This paper reviews the current understanding of cross-linking mechanisms in terms of nuclear and electronic stopping and their impact on materials' properties

  16. Microencapsulation of Lactobacillus acidophilus NCFM using polymerized whey proteins as wall material.

    Science.gov (United States)

    Jiang, Yujun; Zheng, Zhe; Zhang, Tiehua; Hendricks, Gregory; Guo, Mingruo

    2016-09-01

    Survivability of probiotics in foods is essential for developing functional food containing probiotics. We investigated polymerized whey protein (PWP)-based microencapsulation process which is developed for protecting probiotics like Lactobacillus acidophilus NCFM and compared with the method using sodium alginate (SA). The entrapment rate was 89.3 ± 4.8% using PWP, while it was 73.2 ± 1.4% for SA. The microencapsulated NCFM by PWP and SA were separately subjected to digestion juices and post-fermentation storage of fermented cows' and goats' milk using the encapsulated culture. The log viable count of NCFM in PWP-based microencapsulation was 4.56, compared with that of 4.26 in SA-based ones and 3.13 for free culture. Compared with using SA as wall material, PWP was more effective in protecting probiotic. Microencapsulation of L. acidophilus NCFM using PWP as wall material can be exploited in the development of fermented dairy products with better survivability of probiotic organism. PMID:27309796

  17. Ion-beam modification of polymeric materials - fundamental principles and applications

    International Nuclear Information System (INIS)

    When an energetic ion traverses a polymer medium, it loses its energy by electronic and nuclear processes. In the past, considerable research efforts have been devoted to understand the effects of the electronic and nuclear processes in materials. There have been, however, some conflicting reports regarding the roles of electronic and nuclear stopping in producing property changes in polymeric materials, namely the magnitude of cross-linking and scission. A consensus derived from the work conducted at ORNL indicates that electronic stopping is largely responsible for cross-linking and nuclear stopping for scission, although both processes can cause cross-linking as well as scission. The most important parameter for cross-linking is found to be the energy deposited per unit ion path length or linear energy transfer (LET). The mechanisms involved with property changes are discussed by clarifying the concepts of nuclear and electronic stopping, LET, tracks, and spurs. Experimental evidence to support the views are presented. Also addressed are specific property changes induced by ion-beams, which may be of use for industrial applications

  18. Crack initiation and propagation on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing

    Directory of Open Access Journals (Sweden)

    G. M. Domínguez Almaraz

    2015-10-01

    Full Text Available Crack initiation and propagation have been investigated on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing. Three controlled actions were implemented in order to carry out fatigue tests at very high frequency on this material of low thermal conductivity, they are: a The applying load was low to limit heat dissipation at the specimen neck section, b The dimensions of testing specimen were small (but fitting the resonance condition, in order to restraint the temperature gradient at the specimen narrow section, c Temperature at the specimen neck section was restrained by immersion in water or oil during ultrasonic fatigue testing. Experimental results are discussed on the basis of thermo-mechanical behaviour: the tail phenomenon at the initial stage of fatigue, initial shear yielding deformation, crazed development on the later stage, plastic strain on the fracture surface and the transition from low to high crack growth rate. In addition, a numerical analysis is developed to evaluate the J integral of energy dissipation and the stress intensity factor K, with the crack length

  19. The micro-element dynamic in hortic antrosoils conditioned with polymeric materials

    Science.gov (United States)

    Filipov, F.; Bulgariu, D.; Jitareanu, G.; Bulgariu, L.

    2009-04-01

    The studies regarding the dynamic of microelements in hortic anthrosols (soils from glasshouses and solariums) are important both from scientific point of view and in special, for the implementation of durable ecological technologies of amelioration, conservation and superior capitalization of soil resources from protected areas (glasshouses and solariums). In case of hortic anthrosols, the application of intensive technologies for plants cultivation determined brusque and intense perturbations of equilibriums between microelements and mineral and organic components of anthrosols, which is reflected by a fast degradation of morphological and physic-chemical properties. But, in case of hortic anthrosols, the exploitation conditions determined a particular evolution of microelements, and of distributions and interactions way with soil components, respectively. The conditioning and the amelioration of hortic antrosols with ecologic polymeric materials is one of the method approved in this moment and according with the opinion of most of specialists, represent one of method with large applications in modern agriculture. The utilization of polymeric materials to the conditioning of soils have been studied over 50 years, their effects on morphological, physical and chemical properties of soils being know, in special for agricultural and polluted soils. Ours studied have been performed using soil profiles drawing from Copou-glass house, Iasi (Romania). Has been followed the modification of distribution for speciation forms of some micro-elements (Zn, Cu, Ni, Mn, Cr, P), between hortic antrosol horizons, and between chemical-mineralogical components of this, with the progressive salinization of superior horizons, in 2007-2008 period. For the experimental study have been used three types of water-soluble polymers, with different hydrophobicities: polyethylene glycol (molecular mass 2000, 4000 and 8000), vinyl acetate - ammonia maleate salt copolymer (AM-VA) and

  20. Estimating the erosion and degradation performance of ceramic and polymeric insulator materials in high current arc environments

    Energy Technology Data Exchange (ETDEWEB)

    Engel, T.G.; Kristiansen, M.; O' Hair, E. (Texas Tech Univ., Lubbock, TX (United States). Dept. of Electrical Engineering); Marx, J.N. (Texas Tech Univ., Lubbock, TX (United States). Dept. of Chemistry and Biochemistry)

    1991-01-01

    This paper reports on the rates of erosion and voltage holdoff degradation which are critical parameters when selecting insulator materials that are used in pulsed power devices such as spark gaps, surface discharge switches, and electromagnetic launchers. This investigation is concerned with modeling the erosion and holdoff degradation performance of various commercially available polymeric and ceramic insulators. The insulators are tested on a surface discharge switch at {approximately}300 kA in atmospheric air. Test diagnostics include the surface voltage holdoff recovery and the eroded mass loss of the insulator and electrode materials used. The ceramic materials which were tested include several types of aluminum and magnesium silicates, several alumina and zirconia composites, and aluminum and silicon nitride. The polymeric insulators include polyvinyl chloride, low and high molecular weight polyethylene, polytetrafluoroethylene, polyamide, acetyl, polyamide-imide, and several types of glass-reinforced epoxies, melamines, and phenolics.

  1. [Advances in the research of natural polymeric materials and their derivatives in the manufacture of scaffolds for dermal tissue engineering].

    Science.gov (United States)

    Li, R; Wang, H; Leng, C Y; Wang, K; Xie, Y

    2016-05-20

    Natural polymeric materials and their derivatives are organic macromolecular compounds which exist in plants, animals, and micro-organisms. They have been widely used in the preparation of scaffolds for skin tissue engineering recently because of their good histocompatibility and degradability, and low immunogenicity. With the improvement of the preparation technics, composite materials are more commonly used to make scaffolds for dermal tissue engineering. This article summarizes the classification and research status of the commonly used natural polymer materials, their derivatives, and composite scaffold materials, as well as makes a prospect of the research trends of dermal scaffold in the future. PMID:27188491

  2. Barrier Properties of Polymeric Packaging Materials to Major Aroma Volatiles in Herbs

    Directory of Open Access Journals (Sweden)

    Leelaphiwat Pattarin

    2016-01-01

    Full Text Available This study determined the main transport coefficients (diffusion, solubility and permeability of key aroma compounds present in tropical herbs (eucalyptol and estragol through low‒density polyethylene (LDPE, polypropylene (PP, nylon (Nylon, polyethylene terephthalate (PET, metalized‒polyethylene terephthalate (MPET and poly(lactic acid (PLA films at 15 and 25 °C. The concentration of aroma compounds permeating through the films were evaluated at various time intervals using a gas chromatograph flame ionization detector (GC–FID. Results showed that the diffusion coefficients of aroma compounds were highest in LDPE whereas the solubility coefficients were highest in PLA at both temperatures. PLA had the highest permeability coefficients for estragol at both temperatures. PP and LDPE had the highest permeability coefficients for eucalyptol at 15 and 25 °C, respectively. MPET had the lowest permeability for both aroma compounds studied. Aroma barrier properties can be used when selecting polymeric packaging materials to prevent aroma loss in various food and consumer products.

  3. Recent developments in curcumin and curcumin based polymeric materials for biomedical applications: A review.

    Science.gov (United States)

    Mahmood, Kashif; Zia, Khalid Mahmood; Zuber, Mohammad; Salman, Mahwish; Anjum, Muhammad Naveed

    2015-11-01

    Turmeric (Curcuma longa) is a popular Indian spice that has been used for centuries in herbal medicines for the treatment of a variety of ailments such as rheumatism, diabetic ulcers, anorexia, cough and sinusitis. Curcumin (diferuloylmethane) is the main curcuminoid present in turmeric and responsible for its yellow color. Curcumin has been shown to possess significant anti-inflammatory, anti-oxidant, anti-carcinogenic, anti-mutagenic, anticoagulant and anti-infective effects. This review summarizes and discusses recently published papers on the key biomedical applications of curcumin based materials. The highlighted studies in the review provide evidence of the ability of curcumin to show the significant vitro antioxidant, diabetic complication, antimicrobial, neuroprotective, anti-cancer activities and detection of hypochlorous acid, wound healing, treatment of major depression, healing of paracentesis, and treatment of carcinoma and optical detection of pyrrole properties. Hydrophobic nature of this polyphenolic compound along with its rapid metabolism, physicochemical and biological instability contribute to its poor bioavailability. To redress these problems several approaches have been proposed like encapsulation of curcumin in liposomes and polymeric micelles, inclusion complex formation with cyclodextrin, formation of polymer-curcumin conjugates, etc. PMID:26391597

  4. Advances in Auxetic Polymeric Materials%拉胀高分子材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    魏荣; 吴红枚; 李竞; 陈少云; 陈解放; 吴斌

    2013-01-01

    Auxetic materials are special materials that can exhibit negative Poisson's ratio (NPR) effect. This article focused on the present species and advances in research on auxetic polymeric materials, i.e. , foam polymers, microporous polymers, auxetic fibers and composites. Different opinions on the mechanism about auxeticity are introduced and it is worthwhile to point out that further research is still needed. Main directions and hot issues in the field of auxetic polymeric material are also pointed out. At the same time, authors introduce their own opinions and ideas and relevant researches on auxetic polymeric materials. In addition, a prospective on the future application of auxetic polymeric materials is given.%拉胀材料即具有负泊松比的材料.文中在简要介绍负泊松比起源的基础上,重点阐述了拉胀高分子材料目前现有的四大种类:泡沫聚合物、微孔聚合物、拉胀纤维和复合材料,并简述其研究现状.介绍了不同研究者关于拉胀性机理研究的观点、模型,指出拉胀机理的研究有待深入,就拉胀高分子材料领域中的研究方向和热点问题提出了一些独到的观点和看法,介绍了笔者在该方向上的相关工作和思路,并对拉胀高分子这一新材料品种的广阔应用前景予以展望.

  5. Engineered Polymeric Hydrogels for 3D Tissue Models

    Directory of Open Access Journals (Sweden)

    Sujin Park

    2016-01-01

    Full Text Available Polymeric biomaterials are widely used in a wide range of biomedical applications due to their unique properties, such as biocompatibility, multi-tunability and easy fabrication. Specifically, polymeric hydrogel materials are extensively utilized as therapeutic implants and therapeutic vehicles for tissue regeneration and drug delivery systems. Recently, hydrogels have been developed as artificial cellular microenvironments because of the structural and physiological similarity to native extracellular matrices. With recent advances in hydrogel materials, many researchers are creating three-dimensional tissue models using engineered hydrogels and various cell sources, which is a promising platform for tissue regeneration, drug discovery, alternatives to animal models and the study of basic cell biology. In this review, we discuss how polymeric hydrogels are used to create engineered tissue constructs. Specifically, we focus on emerging technologies to generate advanced tissue models that precisely recapitulate complex native tissues in vivo.

  6. Biocompatibility of plasma nanostructured biopolymers

    Czech Academy of Sciences Publication Activity Database

    Kasálková-Slepičková, N.; Slepička, P.; Bačáková, Lucie; Sajdl, P.; Švorčík, V.

    2013-01-01

    Roč. 307, Jul 15 (2013), s. 642-646. ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : biopolymer * plasma treatment * biocompatibility Subject RIV: JJ - Other Materials Impact factor: 1.186, year: 2013

  7. L-Lactide Ring-Opening Polymerization with Tris(acetylacetonate)Titanium(IV) for Renewable Material.

    Science.gov (United States)

    Kim, Da Hee; Yoo, Ji Yun; Ko, Young Soo

    2016-05-01

    A new Ti-type of catalyst for L-lactide polymerization was synthesized by reaction of titanium(IV) isopropoxide (TTIP) with acetylacetone (AA). Moreover, PLA was prepared by the bulk ring-opening polymerization using synthesized Ti catalyst. Polymerization behaviors were examined depending on monomer/catalyst molar ratio, polymerization temperature and time. The structure of synthesized catalysts was verified with FT-IR and 1H NMR and the properties of poly(L-lactide) (PLLA) were examined by GPC, DSC and FT-IR. There existed about 30 minutes of induction time at the monomer/catalyst molar ratio of 300. The molecular weight (MW) increased as monomer/catalyst molar ratio increased. The MW increased almost linearly as polymerization progressed. Increasing polymerization temperature increased the molecular weight of PLLA as well as monomer/catalyst molar ratio. The melting point (T(m)) of polymers was in the range of 142 to 167 degrees C. Lower T(m) was expected to be resulted from relatively lower molecular weight. PMID:27483787

  8. 人角膜接触镜材料生物相容性的研究%Studies on biocompatibility of contact lens material for human cornea

    Institute of Scientific and Technical Information of China (English)

    朱文渊; 刘正堂; 崔英德; 黎新明

    2007-01-01

    Objective To study the biocompatibility of contact lens material for human cornea prepared in our department. Methods Biological properties of the material were assessed by cytotoxicity,haemolysis and protein aggradation. Results The material had no toxicity for HEFC. The haemolysis rate was eligibility(1.62%). Anti-protein-aggradation was quite good. Conclusion The contact lens material by our department possesses quite good biological properties.%目的 研究本室制备的人角膜接触镜材料的生物性能.方法 采用细胞毒性试验、红细胞溶血试验以及蛋白质沉积试验方法.结果 所制备的人角膜接触镜材料对人胚肺纤维细胞(HEFC)毒性评价为1级无毒性;红细胞溶血率为1.62%合格;在体温范围内抗蛋白质沉积作用较好.结论 本室制备的人角膜接触镜材料具有较好的生物相容性.

  9. Biocompatibility of Niobium Coatings

    Directory of Open Access Journals (Sweden)

    René Olivares-Navarrete

    2011-09-01

    Full Text Available Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainless steel substrates and tissue culture plastic were also studied, in order to give comparative information. No toxic response was observed for any of the surfaces, indicating that the Nb coatings act as a biocompatible, bioinert material. Cell morphology was also studied by immune-fluorescence and the results confirmed the healthy state of the cells on the Nb surface. X-ray diffraction analysis of the coating shows that the film is polycrystalline with a body centered cubic structure. The surface composition and corrosion resistance of both the substrate and the Nb coating were also studied by X-ray photoelectron spectroscopy and potentiodynamic tests. Water contact angle measurements showed that the Nb surface is more hydrophobic than the SS substrate.

  10. Thermal Conductivity of Thermally-Isolating Polymeric and Composite Structural Support Materials Between 0.3 and 4 K

    CERN Document Server

    Runyan, M C

    2008-01-01

    We present measurements of the low-temperature thermal conductivity of a number of polymeric and composite materials from 0.3 to 4 K. The materials measured are Vespel SP-1, Vespel SP-22, unfilled PEEK, 30% carbon fiber-filled PEEK, 30% glass-filled PEEK, carbon fiber Graphlite composite rod, Torlon 4301, G-10/FR-4 fiberglass, pultruded fiberglass composite, Macor ceramic, and graphite rod. These materials have moderate to high elastic moduli making them useful for thermally-isolating structural supports.

  11. Synthesis, characterization and polymerization of methacrylates of copper (II), cobalt (II) and molybdenum (II). Generation of new materials

    International Nuclear Information System (INIS)

    Coordination compounds of the species copper (II), cobalt (II) and molybdenum (II) with methacrylic acid were synthesized and characterized. Besides, it realized reactions of bromine addition to the doubles links of the species obtained previously, also too like reactions with dry HCl. Finally, it got hybrids materials by polymerization of the first compounds in an acrylic matrix. Research concluded with the characterization of all the products. (author)

  12. Effect of membrane polymeric materials on relationship between surface pore size and membrane fouling in membrane bioreactors

    Science.gov (United States)

    Miyoshi, Taro; Yuasa, Kotaku; Ishigami, Toru; Rajabzadeh, Saeid; Kamio, Eiji; Ohmukai, Yoshikage; Saeki, Daisuke; Ni, Jinren; Matsuyama, Hideto

    2015-03-01

    We investigated the effect of different membrane polymeric materials on the relationship between membrane pore size and development of membrane fouling in a membrane bioreactor (MBR). Membranes with different pore sizes were prepared using three different polymeric materials, cellulose acetate butyrate (CAB), polyvinyl butyral (PVB), and polyvinylidene fluoride (PVDF), and the development of membrane fouling in each membrane was evaluated by batch filtration tests using a mixed liquor suspension obtained from a laboratory-scale MBR. The results revealed that the optimal membrane pore size to mitigate membrane fouling differed depending on membrane polymeric material. For PVDF membranes, the degree of membrane fouling decreased as membrane pore size increased. In contrast, CAB membranes with smaller pores had less fouling propensity than those with larger ones. Such difference can be attributed to the difference in major membrane foulants in each membrane; in PVDF, they were small colloids or dissolved organics in which proteins are abundant, and in CAB, microbial flocs. The results obtained in this study strongly suggested that optimum operating conditions of MBRs differ depending on the characteristics of the used membrane.

  13. Radiation-induced graft polymerization is the key to develop high-performance functional materials

    International Nuclear Information System (INIS)

    By radiation-induced graft polymerization of an epoxy-group-containing vinyl monomer and subsequent chemical modifications, we succeeded in preparing a novel material in a hollow-fiber form that meets the three requirements for highly efficient protein recovery: high rate, high capacity and repeated use. A diethylamino (DEA) group as a weakly basic anion-exchange group was appended to a porous hollow-fiber membrane. First, we aimed to transport the protein by convection through the pores of the hollow-fiber membrane with immobilized graft chains containing the DEA groups. The protein (bovine serum albumin, BSA) solution was forced to permeate across the ion-exchange porous membrane. As a result, the breakthrough curve was independent of flow rate, i.e., the residence time, because of negligible diffusional mass-transfer resistance. This means that a higher flow rate of the protein solution through the membrane can result in a higher collection rate of the protein. Second, the DEA-group-containing graft chains extended from the pore surface towards the pore interior owing to mutual electrostatic repulsion. A higher density of the DEA groups was found to lead to a higher capacity for protein binding owing to the presence of three-dimensional adsorption sites for proteins. As a result, the membrane could hold an amount of BSA eleven times greater than that which could be adsorbed as a monolayer on the interface. Third, we designed the polymer chain grafted onto a porous polyethylene membrane to enhance selective adsorption of the target proteins by the ion-exchange groups and retard nonselective adsorption of the proteins by alcoholic hydroxyl groups. Quantitative elution of the protein by permeating a buffer solution containing 0.5 M NaCl was achieved for the DEA-containing membrane. A higher rate of elution was also attained by convection of the adsorbed protein from the ion-exchange group to the bulk. (author)

  14. Biocompatible polysaccharide-based cryogels

    International Nuclear Information System (INIS)

    This study focuses on the development of novel biocompatible macroporous cryogels by electron-beam assisted free-radical crosslinking reaction of polymerizable dextran and hyaluronan derivatives. As a main advantage this straightforward approach provides highly pure materials of high porosity without using additional crosslinkers or initiators. The cryogels were characterized with regard to their morphology and their basic properties including thermal and mechanical characteristics, and swellability. It was found that the applied irradiation dose and the chemical composition strongly influence the material properties of the resulting cryogels. Preliminary cytotoxicity tests illustrate the excellent in vitro-cytocompatibility of the fabricated cryogels making them especially attractive as matrices in tissue regeneration procedures. - Graphical abstract: Electron-beam initiated synthesis of biocompatible cryogels based on natural polymers. - Highlights: • Successful electron-beam induced synthesis of dextran and hyaluronan cryogels. • Mechanical and thermal stable cryogels were obtained. • Excellent cytocompatibility of the materials was proven. • Promising materials for tissue engineering were developed

  15. Biocompatible polysaccharide-based cryogels

    Energy Technology Data Exchange (ETDEWEB)

    Reichelt, Senta, E-mail: senta.reichelt@iom-leipzig.de [Leibniz Institute of Surface Modification, Permoserstr. 15, 04318 Leipzig (Germany); Becher, Jana; Weisser, Jürgen [Innovent e.V., Pruessingstr. 27B, 07745 Jena (Germany); Prager, Andrea; Decker, Ulrich [Leibniz Institute of Surface Modification, Permoserstr. 15, 04318 Leipzig (Germany); Möller, Stephanie; Berg, Albrecht; Schnabelrauch, Matthias [Innovent e.V., Pruessingstr. 27B, 07745 Jena (Germany)

    2014-02-01

    This study focuses on the development of novel biocompatible macroporous cryogels by electron-beam assisted free-radical crosslinking reaction of polymerizable dextran and hyaluronan derivatives. As a main advantage this straightforward approach provides highly pure materials of high porosity without using additional crosslinkers or initiators. The cryogels were characterized with regard to their morphology and their basic properties including thermal and mechanical characteristics, and swellability. It was found that the applied irradiation dose and the chemical composition strongly influence the material properties of the resulting cryogels. Preliminary cytotoxicity tests illustrate the excellent in vitro-cytocompatibility of the fabricated cryogels making them especially attractive as matrices in tissue regeneration procedures. - Graphical abstract: Electron-beam initiated synthesis of biocompatible cryogels based on natural polymers. - Highlights: • Successful electron-beam induced synthesis of dextran and hyaluronan cryogels. • Mechanical and thermal stable cryogels were obtained. • Excellent cytocompatibility of the materials was proven. • Promising materials for tissue engineering were developed.

  16. Preparation of epoxy/zirconia hybrid materials via in situ polymerization using zirconium alkoxide coordinated with acid anhydride

    International Nuclear Information System (INIS)

    Highlights: → Novel epoxy/zirconia hybrid materials were synthesized via in situ polymerization using zirconium alkoxide coordinated with acid anhydride. → The half-ester compound of acid anhydride desorbed from zirconium played as curing agent of epoxy resin. → The zirconia was uniformly dispersed in the epoxy matrix on the nanometer or sub-nanometer scale by synchronizing the epoxy curing and sol-gel reactions. → The refractive indices of the hybrid materials significantly improved with an increase in the zirconia content. - Abstract: Novel epoxy/zirconia hybrid materials were synthesized using a bisphenol A epoxy resin (diglycidyl ether of bisphenol A; DGEBA), zirconium(IV)-n-propoxide (ZTNP), and hexahydrophthalic anhydride (HHPA) via in situ polymerization. HHPA played two roles in this system: it acted as a modifier to control the hydrolysis and condensation reactions of zirconium alkoxide and also as a curing agent - the half-ester compound of HHPA desorbed from zirconium reacted with the epoxy resin to form the epoxy network. As a result, both the sol-gel reaction and epoxy curing occurred simultaneously in a homogeneous solution, and organic-inorganic hybrid materials were readily obtained. Further, the zirconia produced by the in situ polymerization was uniformly dispersed in the epoxy matrix on the nanometer or sub-nanometer scale; thus, hybrid materials that exhibited excellent optical transparency were obtained. Furthermore, the heat resistance of the hybrid materials could be improved by hybridization with zirconia. And, the refractive indices of the hybrid materials significantly improved with an increase in the zirconia content.

  17. Preparation of epoxy/zirconia hybrid materials via in situ polymerization using zirconium alkoxide coordinated with acid anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Ochi, Mitsukazu, E-mail: mochi@ipcku.kansai-u.ac.jp [Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Suita-shi, Osaka 564-8680 (Japan); Nii, Daisuke; Harada, Miyuki [Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Suita-shi, Osaka 564-8680 (Japan)

    2011-09-15

    Highlights: {yields} Novel epoxy/zirconia hybrid materials were synthesized via in situ polymerization using zirconium alkoxide coordinated with acid anhydride. {yields} The half-ester compound of acid anhydride desorbed from zirconium played as curing agent of epoxy resin. {yields} The zirconia was uniformly dispersed in the epoxy matrix on the nanometer or sub-nanometer scale by synchronizing the epoxy curing and sol-gel reactions. {yields} The refractive indices of the hybrid materials significantly improved with an increase in the zirconia content. - Abstract: Novel epoxy/zirconia hybrid materials were synthesized using a bisphenol A epoxy resin (diglycidyl ether of bisphenol A; DGEBA), zirconium(IV)-n-propoxide (ZTNP), and hexahydrophthalic anhydride (HHPA) via in situ polymerization. HHPA played two roles in this system: it acted as a modifier to control the hydrolysis and condensation reactions of zirconium alkoxide and also as a curing agent - the half-ester compound of HHPA desorbed from zirconium reacted with the epoxy resin to form the epoxy network. As a result, both the sol-gel reaction and epoxy curing occurred simultaneously in a homogeneous solution, and organic-inorganic hybrid materials were readily obtained. Further, the zirconia produced by the in situ polymerization was uniformly dispersed in the epoxy matrix on the nanometer or sub-nanometer scale; thus, hybrid materials that exhibited excellent optical transparency were obtained. Furthermore, the heat resistance of the hybrid materials could be improved by hybridization with zirconia. And, the refractive indices of the hybrid materials significantly improved with an increase in the zirconia content.

  18. Keratin materials for new product development

    Science.gov (United States)

    Keratin from wool is a reactive, biocompatible, and biodegradable material found as pure protein in over 90% by weight of fiber. As a polymeric amide, keratin is a rich source of intermediate filament proteins (IFPs) which are being investigated for a wide range of biomaterial applications. The po...

  19. Effect of conventional and experimental gingival retraction solutions on the tensile strength and inhibition of polymerization of four types of impression materials

    Directory of Open Access Journals (Sweden)

    Sérgio Sábio

    2008-08-01

    Full Text Available In the present study, two types of tests (tensile strength test and polymerization inhibition test were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic, a polyether (Impregum, a condensation silicone (Xantopren and a polyvinylsiloxane (Aquasil ,3; when polymerized in contact with of one conventional (Hemostop and two experimental (Vislin and Afrin gingival retraction solutions. For the tensile strength test, the impression materials were mixed and packed into a steel plate with perforations that had residues of the gingival retraction solutions. After polymerization, the specimens were tested in tensile strength in a universal testing machine. For the polymerization inhibition test, specimens were obtained after taking impressions from a matrix with perforations that contained 1 drop of the gingival retraction solutions. Two independent examiners decided on whether or not impression material remnants remained unpolymerized, indicating interference of the chemical solutions. Based on the analysis of the results of both tests, the following conclusions were reached: 1. The tensile strength of the polysulfide decreased after contact with Hemostop and Afrin. 2. None of the chemical solutions inhibited the polymerization of the polysulfide; 3. The polyether presented lower tensile strength after polymerization in contact with the three gingival retraction agents; 4. The polyether had its polymerization inhibited only by Hemostop; 5. None of the chemical solutions affected the tensile strength of the condensation silicone; 6. Only Hemostop inhibited the polymerization of the condensation silicone; 7. The polyvinylsiloxane specimens polymerized in contact with Hemostop had significantly lower tensile strength; 8. Neither of the chemical solutions (Afrin and Vislin affected the tensile strength of the polyvinylsiloxane and the condensation silicone; 9. Results of the tensile strength

  20. Evaluation of Thermal Control Coatings and Polymeric Materials Exposed to Ground Simulated Atomic Oxygen and Vacuum Ultraviolet Radiation

    Science.gov (United States)

    Kamenetzky, R. R.; Vaughn, J. A.; Finckenor, M. M.; Linton, R. C.

    1995-01-01

    Numerous thermal control and polymeric samples with potential International Space Station applications were evaluated for atomic oxygen and vacuum ultraviolet radiation effects in the Princeton Plasma Physics Laboratory 5 eV Neutral Atomic Oxygen Facility and in the MSFC Atomic Oxygen Drift Tube System. Included in this study were samples of various anodized aluminum samples, ceramic paints, polymeric materials, and beta cloth, a Teflon-impregnated fiberglass cloth. Aluminum anodizations tested were black duranodic, chromic acid anodize, and sulfuric acid anodize. Paint samples consisted of an inorganic glassy black paint and Z-93 white paint made with the original PS7 binder and the new K2130 binder. Polymeric samples evaluated included bulk Halar, bulk PEEK, and silverized FEP Teflon. Aluminized and nonaluminized Chemfab 250 beta cloth were also exposed. Samples were evaluated for changes in mass, thickness, solar absorptance, and infrared emittance. In addition to material effects, an investigation was made comparing diffuse reflectance/solar absorptance measurements made using a Beckman DK2 spectroreflectometer and like measurements made using an AZ Technology-developed laboratory portable spectroreflectometer.

  1. Surface modification of medical implant materials with hydrophilic polymers for enhanced biocompatibility and delivery of therapeutic agents

    Science.gov (United States)

    Urbaniak, Daniel J.

    2004-11-01

    In the research reported here, the surface modification of medical grade poly(dimethyl siloxane), polyetherurethane, and stainless steel through gamma-radiation grafting of hydrophilic polymers was investigated. Emphasis was placed on developing improved and simplified surface modification methods that produce more stable and more bioacceptible hydrophilic graft surfaces. As a result of this research, new surface modification techniques were developed that yield significantly improved surface stability unachievable using previous surface modification techniques. The surface modification of poly(dimethyl siloxane) with hydrophilic polymers was carried out using gamma radiation initiated graft polymerization. The addition of alkali metal hydroxides afforded a unique way to enhance the grafting of N-vinyl-2 pyrrolidone, dimethylacryamide, 2-methacryloyloxyethyl phosphoryl choline, N,N-dimethyl-N-(methacryloyloxyethyl)-N-(3-sulfopropyl)-ammonium-betaine, N,N-dimethyl-N-(methacrylamidopropyl)-N-(3-sulfopropyl)-ammonium-betaine, and copolymers thereof to silicones. Ethanolamine was found to further enhance the grafting of some hydrophilic polymers to silicone. The resulting hydrophilic surface grafts were resistant to hydrophobic surface rearrangement. This process overcomes previous problems inherent in silicone surface modification. The technique was also found to moderately enhance the grafting of hydrophilic monomers to polyetherurethane and to 316-L stainless steel. The surface modification of 316-L stainless steel was further enhanced by treating the substrates with a chromium III methacrylate bonding agent prior to irradiation. The coatings were evaluated for their potential use as depots for delivering therapeutic agents. The release of ofloxacin from surface-modified poly(dimethyl siloxane) and dexamethasone from surface-modified 316-L stainless steel was evaluated by in-vitro experiments. Therapeutic levels of drugs were released from surface-modified specimens

  2. Comparison of Release-Controlling Efficiency of Polymeric Coating Materials Using Matrix-type Casted Films and Diffusion-Controlled Coated Tablet

    OpenAIRE

    Piao, Zong-Zhu; Lee, Kyoung-Ho; Kim, Dong-Jin; Lee, Hong-gu; Lee, Jaehwi; Oh, Kyung Taek; Lee, Beom-Jin

    2010-01-01

    Polymeric coating materials have been widely used to modify release rate of drug. We compared physical properties and release-controlling efficiency of polymeric coating materials using matrix-type casted film and diffusion-controlled coated tablet. Hydroxypropylmethyl cellulose (HPMC) with low or high viscosity grade, ethylcellulose (EC) and Eudragit® RS100 as pH-independent polymers and Eudragit S100 for enteric coatings were chosen to prepare the casted film and coated tablet. Tensile stre...

  3. On the Rule of Mixtures for Predicting Stress-Softening and Residual Strain Effects in Biological Tissues and Biocompatible Materials

    Directory of Open Access Journals (Sweden)

    Alex Elías-Zúñiga

    2014-01-01

    Full Text Available In this work, we use the rule of mixtures to develop an equivalent material model in which the total strain energy density is split into the isotropic part related to the matrix component and the anisotropic energy contribution related to the fiber effects. For the isotropic energy part, we select the amended non-Gaussian strain energy density model, while the energy fiber effects are added by considering the equivalent anisotropic volumetric fraction contribution, as well as the isotropized representation form of the eight-chain energy model that accounts for the material anisotropic effects. Furthermore, our proposed material model uses a phenomenological non-monotonous softening function that predicts stress softening effects and has an energy term, derived from the pseudo-elasticity theory, that accounts for residual strain deformations. The model’s theoretical predictions are compared with experimental data collected from human vaginal tissues, mice skin, poly(glycolide-co-caprolactone (PGC25 3-0 and polypropylene suture materials and tracheal and brain human tissues. In all cases examined here, our equivalent material model closely follows stress-softening and residual strain effects exhibited by experimental data.

  4. Effects of Antioxidants on Polymeric Coatings for a Fibrous Collagen Material: Leather

    Science.gov (United States)

    One of our research endeavors has focused on an environmentally friendly finishing process that will improve the UV and heat resistance of chrome-free leather. Experiments were conducted by adding 1 to 5% alpha-tocopherol and mixed-tocopherol to the grain layer finishes (polymeric topcoat) of chrom...

  5. Study of biocompatible properties of polymeric scaffolds derived from vegetable oils for application in tissue engineering; Estudo das propriedades biocompativeis de arcaboucos polimericos derivados de oleos vegetais para aplicacao na engenharia de tecidos

    Energy Technology Data Exchange (ETDEWEB)

    Baratela, Fernando Jose Costa

    2015-11-01

    Tissue engineering and regenerative medicine have as main objective the morphologic/functional reestablishment of injured tissues and organs using cells, scaffolds, stem cells and control of immunological/biochemical responses promoted by the body. In addition, materials science seeks to develop biocompatible biomaterials that do not promote unwanted immune responses and provide the re-establishment of the functions of the tissue/organ. Polymers of natural origin stand out as biomaterials to resemble biological macromolecules, similarity to the extracellular matrix, reduced chance of inflammation and chronic pacing low or no toxicity. This study aimed the development of macromolecular arrays originated from epoxidized soybean oil (OSE), analyzing the relationship between the chemical structure/biological activity of the macromolecular arrays for use as biomaterials in tissue engineering. The synthesis of OSE was performed through the oil chemical route, whose efficiency was determined by infrared spectroscopy and the reaction yield of 85%, determined by nuclear magnetic resonance spectroscopy. From the analysis by differential scanning calorimetry, it was detected a decrease of the glass transition temperature of the epoxidized soybean oil polymer (POSE) compared with OSE, suggesting an increase of the growth of polymer chains of POSE. Thermogravimetric analysis was performed to define the OSE degradation profile, which degrades in two steps. The POSE degrades in just one step and shows higher thermal stability by the increased molecular interactions. The hydrophilicity and crosslinking of POSE was promoted by the addition of 2-hydroxyethyl methacrylate (HEMA) with the monomer grafting by gamma irradiation. The results showed an increased mechanical stability, gelation and water absorption with the HEMA content increasing. Finally, the degree of crystallinity for such polymers grafted with HEMA was 27.5%, estimated by X-ray diffractometry. The second stage was

  6. Building Biocompatible Hydrogels for Tissue Engineering of the Brain and Spinal Cord

    Directory of Open Access Journals (Sweden)

    Kimberly B. Bjugstad

    2012-11-01

    Full Text Available Tissue engineering strategies employing biomaterials have made great progress in the last few decades. However, the tissues of the brain and spinal cord pose unique challenges due to a separate immune system and their nature as soft tissue. Because of this, neural tissue engineering for the brain and spinal cord may require re-establishing biocompatibility and functionality of biomaterials that have previously been successful for tissue engineering in the body. The goal of this review is to briefly describe the distinctive properties of the central nervous system, specifically the neuroimmune response, and to describe the factors which contribute to building polymer hydrogels compatible with this tissue. These factors include polymer chemistry, polymerization and degradation, and the physical and mechanical properties of the hydrogel. By understanding the necessities in making hydrogels biocompatible with tissue of the brain and spinal cord, tissue engineers can then functionalize these materials for repairing and replacing tissue in the central nervous system.

  7. Mesoporous and biocompatible surface active silica aerogel synthesis using choline formate ionic liquid.

    Science.gov (United States)

    Meera, Kamal Mohamed Seeni; Sankar, Rajavelu Murali; Jaisankar, Sellamuthu N; Mandal, Asit Baran

    2011-09-01

    In this paper, we report the preparation and characterization of mesoporous and biocompatible transparent silica aerogel by the sol-gel polymerization of tetraethyl orthosilicate using ionic liquid. Choline cation based ionic liquid allows the silica framework to form in a non collapsing environment and controls the pore size of the gel. FT-IR spectra reveal the interaction of ionic liquid with surface -OH of the gel. DSC thermogram giving the evidence of confinement of ionic liquid within the silica matrix, which helps to avoid the shrinkage of the gel during the aging process. Nitrogen sorption measurements of gel prepared with ionic liquid exhibit a low surface area of 100.53 m2/g and high average pore size of 3.74 nm. MTT assay proves the biocompatibility and cell viability of the prepared gels. This new nanoporous silica material can be applied to immobilize biological molecules, which may retain their stability over a longer period. PMID:21565470

  8. Quantification of organic eluates from polymerized resin-based dental restorative materials by use of GC/MS.

    Science.gov (United States)

    Michelsen, Vibeke Barman; Moe, Grete; Skålevik, Rita; Jensen, Einar; Lygre, Henning

    2007-05-01

    Residual monomers, additives and degradation products from resin-based dental restorative materials eluted into the oral cavity may influence the biocompatibility of these materials. Emphasis has been placed on studies addressing cytotoxic, genotoxic and estrogenic potential of these substances. A prerequisite for analyzing the potential of exposure to eluted compounds from dental materials is reliable quantification methods, both real time and accelerated measurements. The purpose of the present study was to quantify nine eluates; 2-hydroxyethyl methacrylate (HEMA), hydroquinone monomethyl ether (MEHQ), camphorquinone (CQ), butylated hydroxytoluene (BHT), ethyl 4-(dimethylamino)benzoate (DMABEE), triethylene glycoldimethacrylate (TEGDMA), trimethylolpropane trimethacrylate (TMPTMA), oxybenzone (HMBP) and drometrizole (TIN P) leaching from specimens of four commonly used resin-based dental materials in ethanol and an aqueous solution. All analyses were performed by use of GC/MS, each component was quantified separately and the results presented in microg mm(-2). This study has shown that elution from various materials differs significantly, not only in the types of eluates, but also regarding amounts of total and of single components. A high amount of HMBP, a UV stabilizer with potential estrogenic activity, was detected from one material in both solutions. PMID:17127109

  9. Preparation and characterization of bio-compatible Fe3O4-Polydopamine spheres with core/shell nanostructure

    International Nuclear Information System (INIS)

    Graphical abstract: Bio-compatible and superparamagnetic Fe3O4-Polydopamine nanocomposites with well-defined core/shell nanostructures have been successfully synthesized by using an in situ self-polymerization method. These unique core/shell materials could be applied in catalyst supports or drug delivery. -Highlights: → A facile in situ self-polymerization method was successfully developed to synthesize bio-compatible and superparamagnetic Fe3O4-Polydopamine (PDA) nanocomposites with well-defined core/shell nanostructures. → The size of the core/shell product can be controlled by varying the size of the central Fe3O4 core, and different thicknesses of the PDA shells are obtained by tuning the dopamine monomer concentration. → To the best of our knowledge, this is first report focused on the controllable synthesis of core/shell Fe3O4-PDA microspheres and the investigation of its cell viability. → These unique core/shell materials would be applied in catalyst supports or drug delivery. - Abstract: Bio-compatible and superparamagnetic Fe3O4-Polydopamine nanocomposites with well-defined core/shell nanostructures have been successfully synthesized by using an in situ self-polymerization method. The size of the core/shell product can be controlled by varying the size of the central Fe3O4 core, and different thicknesses of the PDA shells are obtained by tuning the dopamine monomer concentration. The morphology, phase composition and crystallinity of the as-prepared nanocomposites have been characterized by transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). The 5-dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide (MTT) cytotoxic analysis shows that the product is biocompatible, with a low toxicity. These unique core/shell materials would be applied in catalyst supports or drug delivery.

  10. A novel donor-acceptor polymeric electrochromic material containing carbazole and 1,8-naphtalimide as subunit

    Energy Technology Data Exchange (ETDEWEB)

    Koyuncu, Fatma Baycan, E-mail: fatmabaycan@hotmail.co [Department of Chemistry, Faculty of Sciences and Arts, Canakkale Onsekiz Mart University, 17020 Canakkale (Turkey); Koyuncu, Sermet [Can Vocational School, Canakkale Onsekiz Mart University, 17400 Canakkale (Turkey); Ozdemir, Eyup, E-mail: eozdemir@comu.edu.t [Department of Chemistry, Faculty of Sciences and Arts, Canakkale Onsekiz Mart University, 17020 Canakkale (Turkey)

    2010-07-01

    We report here the synthesis of a novel polymeric electrochromic material containing carbazole (Cbz)-donor and 1,8-napthalimide-acceptor as subunit. The band gap E{sub g} was measured using UV-vis spectroscopy and compared with that obtained by cyclic voltammetry (CV). Due to intramolecular electron transfer from Cbz-donor to 1,8-napthalimide-acceptor, the fluorescence quenching was observed. When the spectro-electrochemical and electrochromic properties of polymer film were investigated, various tones of green color were obtained on the polymeric film. In the positive regime, the polymer film obtained thereby is dark green resulting from the association of carbazolylium cation radicals at oxidized state and then it can be bleached by electrochemical reduction. Besides, in the negative regime, yellowish green color of film converted to blue attributed to reduction of the 1,8-napthalimide moiety. Finally, the polymeric electrochromic exhibits multi-electrochromic behavior, high redox stability, high coloration efficiency and reasonable response time.

  11. A novel donor-acceptor polymeric electrochromic material containing carbazole and 1,8-naphtalimide as subunit

    International Nuclear Information System (INIS)

    We report here the synthesis of a novel polymeric electrochromic material containing carbazole (Cbz)-donor and 1,8-napthalimide-acceptor as subunit. The band gap Eg was measured using UV-vis spectroscopy and compared with that obtained by cyclic voltammetry (CV). Due to intramolecular electron transfer from Cbz-donor to 1,8-napthalimide-acceptor, the fluorescence quenching was observed. When the spectro-electrochemical and electrochromic properties of polymer film were investigated, various tones of green color were obtained on the polymeric film. In the positive regime, the polymer film obtained thereby is dark green resulting from the association of carbazolylium cation radicals at oxidized state and then it can be bleached by electrochemical reduction. Besides, in the negative regime, yellowish green color of film converted to blue attributed to reduction of the 1,8-napthalimide moiety. Finally, the polymeric electrochromic exhibits multi-electrochromic behavior, high redox stability, high coloration efficiency and reasonable response time.

  12. Removal of some dyes from industrial effluents by polymeric materials and gamma-irradiation

    International Nuclear Information System (INIS)

    The radiolysis of two basic dyes (Astrazon Red 6B and Astrazon Blue BG-200%), was investigated as a function of dye concentration, pH, irradiation dose and dose rate. It was found that the Astrazon Red 6B dye showed more radiation degradation than the Astrazon Blue BG-200% dye. Combining irradiation with the conventional treatment enhanced the degree of degradation. Addition of oxygen or hydrogen peroxide showed this enhancement, while nitrogen showed no change. A pH drop was observed and maybe attributed to the degradation of the dye molecules to lower molecular weight compounds such as organic acids. Experiments on the adsorption or exchange the dyes onto GAC, some polymeric ion exchange resins and polymeric membranes were carried out showing that GAC had the highest adsorption capacity. By combined treatment of irradiation and adsorption, the total removal of these toxic dyes was achieved. (author)

  13. Automated system for combinatorial synthesis and high-throughput characterization of polymeric sensor materials

    OpenAIRE

    Kulikov, Valentin

    2007-01-01

    In this thesis, an automated system for combinatorial synthesis and high throughput investigation of electrical properties of conductive polymers is described. The equipment provides a polymerization of defined mixtures of monomers into a thin layer on the addressed work electrodes of a direct electrode array. It is followed by high-throughput screening of current voltage characteristics according to the developed measurement protocol. The electrodes with an interdigital configuration were sp...

  14. Syringyl Methacrylate, a Hardwood Lignin-Based Monomer for High-T g Polymeric Materials

    OpenAIRE

    Holmberg, Angela L.; Reno, Kaleigh H.; Nguyen, Ngoc A.; Wool, Richard P.; Epps, Thomas H.

    2016-01-01

    As viable precursors to a diverse array of macromolecules, biomass-derived compounds must impart wide-ranging and precisely controllable properties to polymers. Herein, we report the synthesis and subsequent reversible addition–fragmentation chain-transfer polymerization of a new monomer, syringyl methacrylate (SM, 2,6-dimethoxyphenyl methacrylate), that can facilitate widespread property manipulations in macromolecules. Homopolymers and heteropolymers synthesized from SM and related monomers...

  15. Compostability of Co-Extruded Starch/Poly(Lactic Acid Polymeric Material Degradation in an Activated Inert Solid Medium

    Directory of Open Access Journals (Sweden)

    Alain Copinet

    2009-07-01

    Full Text Available The aim of this work was to estimate the biodegradation of a co-extruded starch/poly(lactic acid polymeric material using a vermiculite based inert solid medium which could simulate compost medium and enable us to achieve complete carbon balances. At the end of the test the mineralisation rate was compared to those obtained for co-extruded starch/poly(lactic acid polymeric material degradation in compost. It was shown that the mineralisation rate after 45 days of degradation was similar in activated vermiculite medium to the one in compost. A protocol for both extraction and quantification of the carbon included in the different degradation by-products was proposed and the carbon balance of the polymer degradation was followed during the test with a satisfactory accuracy. As the non-degraded PLA and starch material had been retrieved during the test, the evolution of the glass transition temperature and the molecular weight of PLA could be followed. A two-step degradation mechanism was highlighted in inert solid medium, showing the fundamental role of abiotic reactions for PLA degradation in compost.

  16. Bioglass: A novel biocompatible innovation

    Directory of Open Access Journals (Sweden)

    Vidya Krishnan

    2013-01-01

    Full Text Available Advancement of materials technology has been immense, especially in the past 30 years. Ceramics has not been new to dentistry. Porcelain crowns, silica fillers in composite resins, and glass ionomer cements have already been proved to be successful. Materials used in the replacement of tissues have come a long way from being inert, to compatible, and now regenerative. When hydroxyapatite was believed to be the best biocompatible replacement material, Larry Hench developed a material using silica (glass as the host material, incorporated with calcium and phosphorous to fuse broken bones. This material mimics bone material and stimulates the regrowth of new bone material. Thus, due to its biocompatibility and osteogenic capacity it came to be known as "bioactive glass-bioglass." It is now encompassed, along with synthetic hydroxyapatite, in the field of biomaterials science known as "bioactive ceramics." The aim of this article is to give a bird′s-eye view, of the various uses in dentistry, of this novel, miracle material which can bond, induce osteogenesis, and also regenerate bone.

  17. Improving biocompatibility of implants with nanolayering

    OpenAIRE

    Homar, Miha; GAŠPERLIN, MIRJANA; Dolenc, Andrej; Kristl, Julijana

    2015-01-01

    Biocompatibility of different materials in the body is very complicated phenomenon. Although structural characteristics of implant are decisive for its specific purpose, biologic response mainly depends on surface characteristics of the implant and its interaction with biologic environment. Nanolayering of the implant to improve biocompatibility presents a recent innovation in this field of research. One method of nanolayering is layer-by-layer assembly which has many advantages over other na...

  18. A biocompatible magnetic film: synthesis and characterization

    OpenAIRE

    Chatterjee, Jhunu; Haik, Yousef; Chen, Ching Jen

    2004-01-01

    Background Biotechnology applications of magnetic gels include biosensors, targeted drug delivery, artificial muscles and magnetic buckles. These gels are produced by incorporating magnetic materials in the polymer composites. Methods A biocompatible magnetic gel film has been synthesized using polyvinyl alcohol. The magnetic gel was dried to generate a biocompatible magnetic film. Nanosized iron oxide particles (γ-Fe2O3, ~7 nm) have been used to produce the magnetic gel. Results The surface ...

  19. Recent achievements in the use of radiation polymerization and grafting for biomedical applications

    International Nuclear Information System (INIS)

    Papers mainly published in the last few years on radiation processing of polymeric systems for biomedical applications carried out in different laboratories are reviewed. Radiation-induced polymerization to obtain hydrogels as carriers for immobilization of bioactive agents and for controlled release of drugs is described. Radiation modification of polymers by graft copolymerization and/or crosslinking for the same purposes is also reported. The second part of the paper deals with the work recently carried out in the author's laboratory. Radiation-induced polymerization at low temperatures to obtain matrices susceptible to entrap drugs, including peptides and proteins, is discussed. Radiation grafting of hydrophilic monomers onto relatively new inorganic polymers, i.e. polyphosphazenes, and the properties of such modified polymeric materials, together with their biocompatibility, are summarized. (author)

  20. ROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering

    Directory of Open Access Journals (Sweden)

    Franziska Weichelt

    2010-12-01

    Full Text Available Porous monolithic inorganic/polymeric hybrid materials have been prepared via ring-opening metathesis copolymerization starting from a highly polar monomer, i.e., cis-5-cyclooctene-trans-1,2-diol and a 7-oxanorborn-2-ene-derived cross-linker in the presence of porogenic solvents and two types of inorganic nanoparticles (i.e., CaCO3 and calcium hydroxyapatite, respectively using the third-generation Grubbs initiator RuCl2(Py2(IMesH2(CHPh. The physico-chemical properties of the monolithic materials, such as pore size distribution and microhardness were studied with regard to the nanoparticle type and content. Moreover, the reinforced monoliths were tested for the possible use as scaffold materials in tissue engineering, by carrying out cell cultivation experiments with human adipose tissue-derived stromal cells.

  1. Radiation effects on some polymeric materials and their utilization for possible practical applications

    International Nuclear Information System (INIS)

    The present study divided into two parts. First part focused on the effect of the radiation on some naturally occurring polymers such as chitosan, sodium alginate and carboxymethylcellulose for controlling the degradation process of these polymers. These polymers of low molecular weights can be used as growth promoters for plants in the agriculture field. Second part focused on the radiation grafting of VAc/HEMA binary monomers onto PFA films using gamma irradiation was carried out to synthesize the graft copolymer membranes by direct method. The complexing ability with some selected transition metal ions such as Cu2+ and Cr3+ ions was investigated. These graft copolymer membranes can be used in the field of blood biocompatibility and in waste treatment of some heavy metals in the environmental industrial wastes

  2. Cytotoxicity and Initial Biocompatibility of Endodontic Biomaterials (MTA and Biodentine™ Used as Root-End Filling Materials

    Directory of Open Access Journals (Sweden)

    Diana María Escobar-García

    2016-01-01

    Full Text Available Objective. The aim of this study was to evaluate the cytotoxicity and cellular adhesion of Mineral Trioxide Aggregate (MTA and Biodentine (BD on periodontal ligament fibroblasts (PDL. Methods. PDL cells were obtained from nonerupted third molars and cultured; MTS cellular profusion test was carried out in two groups: MTA and BD, with respective controls at different time periods. Also, the LIVE/DEAD assay was performed at 24 h. For evaluation of cellular adhesion, immunocytochemistry was conducted to discern the expression of Integrin β1 and Vinculin at 12 h and 24 h. Statistical analysis was performed by the Kruskal-Wallis and Mann-Whitney U tests. Results. MTA and BD exhibited living cells up to 7 days. More expressions of Integrin β1 and Vinculin were demonstrated in the control group, followed by BD and MTA, which also showed cellular loss and morphological changes. There was a significant difference in the experimental groups cultured for 5 and 7 days compared with the control, but there was no significant statistical difference between both cements. Conclusions. Neither material was cytotoxic during the time evaluated. There was an increase of cell adhesion through the expression of focal contacts observed in the case of BD, followed by MTA, but not significantly.

  3. In vitro and in vivo biocompatibility and osteogenesis of graphene-reinforced nanohydroxyapatite polyamide66 ternary biocomposite as orthopedic implant material

    Science.gov (United States)

    Zhang, Shiyang; Yang, Qiming; Zhao, Weikang; Qiao, Bo; Cui, Hongwang; Fan, Jianjun; Li, Hong; Tu, Xiaolin; Jiang, Dianming

    2016-01-01

    Graphene and its derivatives have been receiving increasing attention regarding their application in bone tissue engineering because of their excellent characteristics, such as a vast specific surface area and excellent mechanical properties. In this study, graphene-reinforced nanohydroxyapatite/polyamide66 (nHA/PA66) bone screws were prepared. The results of scanning electron microscopy observation and X-ray diffraction data showed that both graphene and nHA had good dispersion in the PA66 matrix. In addition, the tensile strength and elastic modulus of the composites were significantly improved by 49.14% and 21.2%, respectively. The murine bone marrow mesenchymal stem cell line C3H10T1/2 exhibited better adhesion and proliferation in graphene reinforced nHA/PA66 composite material compared to the nHA/PA66 composites. The cells developed more pseudopods, with greater cell density and a more distinguishable cytoskeletal structure. These results were confirmed by fluorescent staining and cell viability assays. After C3H10T1/2 cells were cultured in osteogenic differentiation medium for 7 and 14 days, the bone differentiation-related gene expression, alkaline phosphatase, and osteocalcin were significantly increased in the cells cocultured with graphene reinforced nHA/PA66. This result demonstrated the bone-inducing characteristics of this composite material, a finding that was further supported by alizarin red staining results. In addition, graphene reinforced nHA/PA66 bone screws were implanted in canine femoral condyles, and postoperative histology revealed no obvious damage to the liver, spleen, kidneys, brain, or other major organs. The bone tissue around the implant grew well and was directly connected to the implant. The soft tissues showed no obvious inflammatory reaction, which demonstrated the good biocompatibility of the screws. These observations indicate that graphene-reinforced nHA/PA66 composites have great potential for application in bone tissue

  4. EFFECT OF CONVENTIONAL AND EXPERIMENTAL GINGIVAL RETRACTION SOLUTIONS ON THE TENSILE STRENGTH AND INHIBITION OF POLYMERIZATION OF FOUR TYPES OF IMPRESSION MATERIALS

    OpenAIRE

    Sérgio Sábio; Paulo Afonso Franciscone; José Mondelli

    2008-01-01

    In the present study, two types of tests (tensile strength test and polymerization inhibition test) were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic), a polyether (Impregum), a condensation silicone (Xantopren) and a polyvinylsiloxane (Aquasil) ,3; when polymerized in contact with of one conventional (Hemostop) and two experimental (Vislin and Afrin) gingival retraction solutions. For the tensile strength test, the i...

  5. Polymeric Materials Synthesis by Oxidative Polymerization of Triacylglycerides and Derivatives [Síntese de Materiais Poliméricos por Polimerização Oxidativa de Triacilglicerídeos e Derivados

    Directory of Open Access Journals (Sweden)

    Simoni M. P. Men eghetti

    2013-02-01

    Full Text Available Alkyd resins are essential components of certain classes of paints. They typically have in their composition vegetable oils or fatty acid derivatives which contain in their carbon chain a certain degree of unsaturations (CC double bonds. The presence of these unsaturations allows prompting chemical reactions that lead to the oxidative polymerization of the material (reaction with molecular oxygen present in the air. Due to these chemical characteristics the resin becomes a polymeric structure which leads to the formation of a film over the surface, protecting and beautifying it.

  6. Wear resistance of thick diamond like carbon coatings against polymeric materials used in single screw plasticizing technology

    Science.gov (United States)

    Zitzenbacher, G.; Liu, K.; Forsich, C.; Heim, D.

    2015-05-01

    Wear on the screw and barrel surface accompany polymer single screw plasticizing technology from the beginning. In general, wear on screws can be reduced by using nitrided steel surfaces, fused armour alloys on the screw flights and coatings. However, DLC-coatings (Diamond Like Carbon) comprise a number of interesting properties such as a high hardness, a low coefficient of friction and an excellent corrosion resistance due to their amorphous structure. The wear resistance of about 50 µm thick DLC-coatings against polyamide 6.6, polybutylene terephthalate and polypropylene is investigated in this paper. The tribology in the solids conveying zone of a single screw extruder until the beginning of melting is evaluated using a pin on disc tribometer and a so called screw tribometer. The polymeric pins are pressed against coated metal samples using the pin on disc tribometer and the tests are carried out at a defined normal force and sliding velocity. The screw tribometer is used to perform tribological experiments between polymer pellets and rotating coated metal shafts simulating the extruder screw. Long term experiments were performed to evaluate the wear resistance of the DLC-coating. A reduction of the coefficient of friction can be observed after a frictional distance of about 20 kilometers using glass fibre reinforced polymeric materials. This reduction is independent on the polymer and accompanied by a black layer on the wear surface of the polymeric pins. The DLC-coated metal samples show an up to 16 µm deep wear track after the 100 kilometer test period against the glass fiber filled materials only.

  7. Versatile Method for Producing 2D and 3D Conductive Biomaterial Composites Using Sequential Chemical and Electrochemical Polymerization.

    Science.gov (United States)

    Severt, Sean Y; Ostrovsky-Snider, Nicholas A; Leger, Janelle M; Murphy, Amanda R

    2015-11-18

    Flexible and conductive biocompatible materials are attractive candidates for a wide range of biomedical applications including implantable electrodes, tissue engineering, and controlled drug delivery. Here, we demonstrate that chemical and electrochemical polymerization techniques can be combined to create highly versatile silk-conducting polymer (silk-CP) composites with enhanced conductivity and electrochemical stability. Interpenetrating silk-CP composites were first generated via in situ deposition of polypyrrole during chemical polymerization of pyrrole. These composites were sufficiently conductive to serve as working electrodes for electropolymerization, which allowed an additional layer of CP to be deposited on the surface. This sequential method was applied to both 2D films and 3D sponge-like silk scaffolds, producing conductive materials with biomimetic architectures. Overall, this two-step technique expanded the range of available polymers and dopants suitable for the synthesis of mechanically robust, biocompatible, and highly conductive silk-based materials. PMID:26544990

  8. Ternary europium mesoporous polymeric hybrid materials Eu(β-diketonate)3pvpd-SBA-15(16): host–guest construction, characterization and photoluminescence

    International Nuclear Information System (INIS)

    Novel organic–inorganic mesoporous luminescent polymeric hybrid materials containing europium(III) complexes incorporated to mesoporous silica SBA-15/SBA-16 have been prepared by simple physical doping (impregnation) methods, followed by the addition polymerization reaction of the monomer 4-vinylpyridine (vpd) extending along the mesoporous channels. The precursor europium(III) complexes are synthesized by β-diketonate (β-diketonate=2-thenoyltrifluoroacetonate (tta), hexafluoroacetylacetonate (hfac), trifluoroacetylacetonate (taa)) and monomer 4-vinylpyridine (vpd) coordinated to Eu3+, and SBA-15/SBA-16 are obtained via a sol–gel process. After the physical doping and the polymerization reaction, the final ternary materials Eu(β-diketonate)3pvpd-SBA-15/Eu(β-diketonate)3pvpd-SBA-16 (β-diketonate=tta, hfac, taa) are received. The physical properties and espeically the photoluminescence of these hybrids are characterized, and the XRD and BET results reveal that all of these hybrid materials have uniformity in the mesostructure. The detailed luminescence investigation on all the materials show that Eu(tta)3pvpd-SBA-16 have the highest luminescence intensity and the materials with taa ligands have longer lifetimes. - Grapical abstract: Luminescent mesoporous polymeric hybrid materials containing europium complexes hydrogen bonding to silica SBA-15/SBA-16 followed by the addition polymerization reaction of 4-vinylpyridine (vpd) extending along the mesoporous channels. Highlights: ► Functional mesoporous with simple impregnation method. ► New lanthanide mesoporous hybrids with polymer ligands. ► Luminescence in visible region.

  9. Biocompatibility of different post-core materials in molar repairing%不同桩核修复磨牙的生物相容性比较

    Institute of Scientific and Technical Information of China (English)

    蔡娟; 郁章欣; 吴金枝; 刘新庆

    2013-01-01

      背景:磨牙是主要的功能牙齿,磨牙的修复应能改善其生物功能和具有坚固的组织学效果。目的:评价不同桩核材料在磨牙修复中的应用效果。方法:对应用银汞桩核、铸造桩核和纤维桩核修复磨牙缺损的患者进行随访观察,检查修复体松动、折断、脱落以及牙周炎和牙龈炎等发生情况,X 射线检查桩核冠修复体与牙体间的结合情况以及根管折断情况和根尖根周牙槽骨吸收情况,评价不同桩核材料修复磨牙的生物相容性并进行比较。结果与结论:银汞桩核、铸造桩核和纤维桩核修复磨牙均可以获得较好的治疗效果,但是,与铸造桩核相比较,银汞桩核和纤维桩核的生物性能更好,修复体松动、折断和脱落的发生率更低,根尖根周等炎性并发症的发生率也更低,并且组织学坚固效果更好,是磨牙修复中首选的桩核材料。%BACKGROUND: Molars are the main functional teeth, and molar repairing is able to improve the biological function of molars and has the sturdy histological effect. OBJECTIVE: To evaluate the application effect of different post-core materials in molar repairing. METHODS: The patients received molar repairing with amalgam post-core, cast post-core and fiber post-core were fol owed-up to observe the incidence of prosthesis loosening, fracture, loss, periodontitis and gingivitis. The combination between post-core crown prosthesis and dental body, broken root canal and the resorption of alveolar bone of root tip and root body were tested with X-ray film. The biocompatibility of different post-core materials used for molar repairing was evaluated and compared.RESULTS AND CONCLUSION: The amalgam post-core, cast post-core and fiber post-core have good effects for the repair of molars. But compared with cast post-core, the amalgam post-core and fiber post-core have better biocompatibility, lower incidence of prosthesis

  10. Surface Modification of Biodegradable Polymers towards Better Biocompatibility and Lower Thrombogenicity.

    Directory of Open Access Journals (Sweden)

    Andreas Rudolph

    Full Text Available Drug-eluting stents (DES based on permanent polymeric coating matrices have been introduced to overcome the in stent restenosis associated with bare metal stents (BMS. A further step was the development of DES with biodegradable polymeric coatings to address the risk of thrombosis associated with first-generation DES. In this study we evaluate the biocompatibility of biodegradable polymer materials for their potential use as coating matrices for DES or as materials for fully bioabsorbable vascular stents.Five different polymers, poly(L-lactide PLLA, poly(D,L-lactide PDLLA, poly(L-lactide-co-glycolide P(LLA-co-GA, poly(D,L-lactide-co-glycolide P(DLLA-co-GA and poly(L-lactide-co-ε-caprolactone, P(LLA-co-CL were examined in vitro without and with surface modification. The surface modification of polymers was performed by means of wet-chemical (NaOH and ethylenediamine (EDA and plasma-chemical (O2 and NH3 processes. The biocompatibility studies were performed on three different cell types: immortalized mouse fibroblasts (cell line L929, human coronary artery endothelial cells (HCAEC and human umbilical vein endothelial cells (HUVEC. The biocompatibility was examined quantitatively using in vitro cytotoxicity assay. Cells were investigated immunocytochemically for expression of specific markers, and morphology was visualized using confocal laser scanning (CLSM and scanning electron (SEM microscopy. Additionally, polymer surfaces were examined for their thrombogenicity using an established hemocompatibility test.Both endothelial cell types exhibited poor viability and adhesion on all five unmodified polymer surfaces. The biocompatibility of the polymers could be influenced positively by surface modifications. In particular, a reproducible effect was observed for NH3-plasma treatment, which enhanced the cell viability, adhesion and morphology on all five polymeric surfaces.Surface modification of polymers can provide a useful approach to enhance their

  11. Evaluation of cytotoxicity of polypyrrole nanoparticles synthesized by oxidative polymerization

    International Nuclear Information System (INIS)

    Highlights: ► Polypyrrole nanoparticles synthesized by environmentally friendly polymerization at high concentrations are cytotoxic. ► Primary mouse embryonic fibroblast, mouse hepatoma and human T lymphocyte Jurkat cell lines were treated by Ppy nanoparticles. ► Polypyrrole nanoparticles at high concentrations inhibit cell proliferation. -- Abstract: Polypyrrole (Ppy) is known as biocompatible material, which is used in some diverse biomedical applications and seeming to be a very promising for advanced biotechnological applications. In order to increase our understanding about biocompatibility of Ppy, in this study pure Ppy nanoparticles (Ppy-NPs) of fixed size and morphology were prepared by one-step oxidative polymerization and their cyto-compatibility was evaluated. The impact of different concentration of Ppy nanoparticles on primary mouse embryonic fibroblasts (MEF), mouse hepatoma cell line (MH-22A), and human T lymphocyte Jurkat cell line was investigated. Cell morphology, viability/proliferation after the treatment by Ppy nanoparticles was evaluated. Obtained results showed that Ppy nanoparticles at low concentrations are biocompatible, while at high concentrations they became cytotoxic for Jurkat, MEF and MH-22A cells, and it was found that cytotoxic effect is dose-dependent

  12. Evaluation of cytotoxicity of polypyrrole nanoparticles synthesized by oxidative polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vaitkuviene, Aida [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Kaseta, Vytautas [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Voronovic, Jaroslav [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Ramanauskaite, Giedre; Biziuleviciene, Gene [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Ramanaviciene, Almira [NanoTechnas–Center of Nanotechnology and Material Science at Department of Analytical and Environmental Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, 03225 Vilnius (Lithuania); Ramanavicius, Arunas, E-mail: Arunas.Ramanavicius@chf.vu.lt [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Laboratory of BioNanoTechnology, Department of Materials Science and Electronics, Institute of Semiconductor Physics, State Scientific Research Institute Centre for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius (Lithuania)

    2013-04-15

    Highlights: ► Polypyrrole nanoparticles synthesized by environmentally friendly polymerization at high concentrations are cytotoxic. ► Primary mouse embryonic fibroblast, mouse hepatoma and human T lymphocyte Jurkat cell lines were treated by Ppy nanoparticles. ► Polypyrrole nanoparticles at high concentrations inhibit cell proliferation. -- Abstract: Polypyrrole (Ppy) is known as biocompatible material, which is used in some diverse biomedical applications and seeming to be a very promising for advanced biotechnological applications. In order to increase our understanding about biocompatibility of Ppy, in this study pure Ppy nanoparticles (Ppy-NPs) of fixed size and morphology were prepared by one-step oxidative polymerization and their cyto-compatibility was evaluated. The impact of different concentration of Ppy nanoparticles on primary mouse embryonic fibroblasts (MEF), mouse hepatoma cell line (MH-22A), and human T lymphocyte Jurkat cell line was investigated. Cell morphology, viability/proliferation after the treatment by Ppy nanoparticles was evaluated. Obtained results showed that Ppy nanoparticles at low concentrations are biocompatible, while at high concentrations they became cytotoxic for Jurkat, MEF and MH-22A cells, and it was found that cytotoxic effect is dose-dependent.

  13. Hydrophobic coating of solid materials by plasma-polymerized thin film using tetrafluoroethylene

    Science.gov (United States)

    Hozumi, K.; Kitamura, K.; Kitade, T.

    1980-01-01

    Glass slides were coated with plasma-polymerized tetrafluoroethylene films of different thickness using the glow discharge technique in a tube-shaped chamber, and the plasma conditions, film growth rates, light permeability of the polymer films, and particle bond strength in the polymer films were studied. Ashed sections of mouse organs and ashed bacillus spores were also coated to give them hydrophobic treatment without damaging their shapes or appearance. The hydrophobic coating of the specimens was successful, and the fine ash patterns were strongly fixed onto the glass slides, making permanent preparations.

  14. Physical chemistry research for engineering and applied sciences, v.2 polymeric materials and processing

    CERN Document Server

    Pearce, Eli M; Pethrick, Richard A

    2015-01-01

    PrefaceInvestigation on the Influence of a Strong Electric Field on the Electrical, Transport and Diffusion Properties of Carbon Nanostructures; S. A. Sudorgin and N. G. LebedevA Study Thermal Stability of Polyurethane Elastomers; I. A. Novakov, M. A. Vaniev, D. V. Medvedev, N. V. Sidorenko, G. V. Medvedev, and D. O. GusevTrends in Aromatic Polyesters; Z. S. Khasbulatova and G. E. ZaikovMicroheterogeneous Titanium Ziegler-Natta Catalysts: 1,3-Diene Polymerization Under Ultrasound Irradiations; V. P. Zakharov, V. Z. Mingaleev, I. D. Zakirov

  15. Facile electrochemical polymerization of polypyrrole film applied as cathode material in dual rotating disk photo fuel cell

    Science.gov (United States)

    Li, Kan; Zhang, Hongbo; Tang, Tiantian; Tang, Yanping; Wang, Yalin; Jia, Jinping

    2016-08-01

    Polypyrrole (PPy) film is synthesized on Ti substrate through electrochemical polymerization method and is applied as cathode material in a TiO2 NTs-PPy dual rotating disk photo fuel cell (PFC). The optimized PPy electrochemical polymerization is carried out using linear sweep voltammetry from 0 V to 1.2 V (vs. SCE) with scan rate of 0.1 V s-1, 100 circles. Sixty milliliter real textile wastewater with the initial COD and conductivity of 408 ± 6 mgO2 L-1 and 20180 μS cm-1 is treated in this PFC under UV irradiation. About 0.46 V open-circuit voltage (VOC) and 1.8-2.2 mA short-circuit current (JSC) are obtained. Due to the effective electron-hole separation effect, the COD removal rate is as high as 0.0055 min-1. Stable current and COD removal can be obtained at different output voltage. Two influence factors including rotating speed and pH are investigated. Better electricity generation performance and COD removal activity are achieved at high rotating speed and in acidic condition. In comparison with platinized cathode, though VOC is lower, similar JSC is measured. Considering the high cost of Pt, PPy is a promising alternative cathode material in PFC that can also generate electricity efficiently and stably.

  16. The influence of tailored nano/micro polymeric aggregates on material properties of cement-based systems

    International Nuclear Information System (INIS)

    Durability and service life in civil engineering are largely related to the corrosion-related phenomena affecting the steel reinforcement. Damage initiation and/or the development of structural properties start on nano/micro level. Therefore, modification of the material structure on these levels is more likely to effectively deal with the aforementioned durability issues. This work is part of a comprehensive study on novel approaches for corrosion control in reinforced concrete and includes investigation on the influence of tailored nano/micro range polymeric aggregates on material properties of both steel and concrete. The mechanisms related to corrosion and corrosion control are hereby discussed in terms of the possibility for establishing a durable and sustainable solution i.e. self-healing mechanisms in reinforced concrete by using polymeric micelles, vesicles or hybrid aggregates. The feasibility of self-healing is briefly presented via preliminary tests in model liquid environment. Additionally, the significant impact of minimal concentrations of nano-aggregates on global properties of the cementitious bulk matrix is also discussed. Key words: corrosion; micelles; hybrid aggregates; mortar; EIS; PDP; SEM

  17. Surface modification of polymers for biocompatibility via exposure to extreme ultraviolet radiation

    OpenAIRE

    Ahad, I.U.; Bartnik, A.; Fiedorowicz, Henryk; Kostecki, Jerzy; Korkzyc, Barbara; Ciach, Tomasz; Brabazon, Dermot

    2013-01-01

    Polymeric biomaterials are being widely used for the treatment of various traumata, diseases and defects in human beings due to ease in their synthesis. As biomaterials have direct interaction with the extracellular environment in the biological world, biocompatibility is a topic of great significance. The introduction or enhancement of biocompatibility in certain polymers is still a challenge to overcome. Polymer biocompatibility can be controlled by surface modification. Various physical an...

  18. A total cost perspective on use of polymeric materials in solar collectors – Importance of environmental performance on suitability

    International Nuclear Information System (INIS)

    Highlights: • A polymeric solar collector system was compared with two traditional ones. • It was found the best in terms of climatic performance per solar heat collected. • The differences in climatic cost between the systems compared however are small. • The low climatic cost makes solar heating better compared to natural gas heating. • Use of Ecoindicator 99 for environmental cost makes solar heating even better. - Abstract: To assess the suitability of solar collector systems in which polymeric materials are used versus those in which more traditional materials are used, a case study was undertaken. In this case study a solar heating system with polymeric solar collectors was compared with two equivalent but more traditional solar heating systems: one with flat plate solar collectors and one with evacuated tube solar collectors. To make the comparison, a total cost accounting approach was adopted. The life cycle assessment (LCA) results clearly indicated that the polymeric solar collector system is the best as regards climatic and environmental performance when they are expressed in terms of the IPPC 100 a indicator and the Ecoindicator 99, H/A indicator, respectively. In terms of climatic and environmental costs per amount of solar heat collected, the differences between the three kinds of collector systems were small when compared with existing energy prices. With the present tax rates, it seems unlikely that the differences in environmental and climatic costs will have any significant influence on which system is the most favoured, from a total cost point of view. In the choice between a renewable heat source and a heat source based on the use of a fossil fuel, the conclusion was that for climatic performance to be an important economic factor, the tax or trade rate of carbon dioxide emissions must be increased significantly, given the initial EU carbon dioxide emission trade rate. The rate would need to be at least of the same order of magnitude

  19. Functionally graded polymeric materials: A brif review of current fabrication methods and introduction of a novel fabrication method.

    Science.gov (United States)

    Almasi, Davood; Sadeghi, Maliheh; Lau, Woei Jye; Roozbahani, Fatemeh; Iqbal, Nida

    2016-07-01

    The present work reviews the current fabrication methods of the functionally graded polymeric material (FGPM) and introduces a novel fabrication method that is versatile in applications as compared to those of existing used methods. For the first time electrophoresis was used to control the distribution of the tetracycline hydrochloride (TC) in a film made of polylactic acid (PLA), aiming to induce antimicrobial effect on the film prepared. The elemental analysis on the film surface showed that by employing electrophoresis force, higher amount of TC was detected near the top surface of the film. Results also showed that the FGPM samples with higher percentage of the TC on the film surface were highly effective to minimize the growth of Escherichia coli. These findings are useful and important to improve dispersion quality of the particles in the composite material and further enhance its antibacterial property. PMID:27127033

  20. Synthesis and Properties of Electroconductive Polymeric Composite Material Based on Polypyrrole

    OpenAIRE

    Ilicheva, N. S.; Kitaeva, N. K.; Duflot, V. R.; V. I. Kabanova

    2012-01-01

    A technique is proposed for obtaining electroconductive, mechanically strong, and elastic composite material based on polypyrrole and hydrophilized polyethylene. The relationship is established between the process parameters and properties of the composite material such as electroconductivity and mechanical strength. Several methods are considered in the view of increasing electroconductivity of the material. Physical and mechanical properties of the composite material are investigated.

  1. Polymeric implant materials for the reconstruction of tracheal and pharyngeal mucosal defects in head and neck surgery

    Directory of Open Access Journals (Sweden)

    Rickert, Dorothee

    2009-01-01

    Full Text Available The existing therapeutical options for the tracheal and pharyngeal reconstruction by use of implant materials are described. Inspite of a multitude of options and the availability of very different materials none of these methods applied for tracheal reconstruction were successfully introduced into the clinical routine. Essential problems are insufficiencies of anastomoses, stenoses, lack of mucociliary clearance and vascularisation. The advances in Tissue Engineering (TE offer new therapeutical options also in the field of the reconstructive surgery of the trachea. In pharyngeal reconstruction far reaching developments cannot be recognized at the moment which would allow to give a prognosis of their success in clinical application. A new polymeric implant material consisting of multiblock copolymers was applied in our own work which was regarded as a promising material for the reconstruction of the upper aerodigestive tract (ADT due to its physicochemical characteristics. In order to test this material for applications in the ADT under extreme chemical, enzymatical, bacterial and mechanical conditions we applied it for the reconstruction of a complete defect of the gastric wall in an animal model. In none of the animals tested either gastrointestinal complications or negative systemic events occurred, however, there was a multilayered regeneration of the gastric wall implying a regular structured mucosa.In future the advanced stem cell technology will allow further progress in the reconstruction of different kind of tissues also in the field of head and neck surgery following the principles of Tissue Engineering.

  2. Current and future biocompatibility aspects of biomaterials for hip prosthesis

    Directory of Open Access Journals (Sweden)

    Amit Aherwar

    2015-12-01

    Full Text Available The field of biomaterials has turn into an electrifying area because these materials improve the quality and longevity of human life. The first and foremost necessity for the selection of the biomaterial is the acceptability by human body. However, the materials used in hip implants are designed to sustain the load bearing function of human bones for the start of the patient’s life. The most common classes of biomaterials used are metals, polymers, ceramics, composites and apatite. These five classes are used individually or in combination with other materials to form most of the implantation devices in recent years. Numerous current and promising new biomaterials i.e. metallic, ceramic, polymeric and composite are discussed to highlight their merits and their frailties in terms of mechanical and metallurgical properties in this review. It is concluded that current materials have their confines and there is a need for more refined multi-functional materials to be developed in order to match the biocompatibility, metallurgical and mechanical complexity of the hip prosthesis.

  3. Adhesive and Stress-Strain Properties of the Polymeric Layered Materials Reinforced by the Knitted Net

    Directory of Open Access Journals (Sweden)

    Rakhimov Farhod Hushbakovich

    2012-10-01

    Full Text Available It is known that the textile materials (woven fabric and mesh used for reinforcing of various polymer films and coatings. This paper discusses reinforcement of thermoplastic polymers based on PE (Polyethylene and PVC (Polyvinyl Chloride with a knitted mesh weave loin. According by the research identified adhesion, strength and deformation properties of new polymer laminates. The production of such materials has been discussed in detail and performance of resultant composites material is analyzed and compared with other materials.

  4. Structure and properties of polymeric composite materials during 1501 days outer space exposure at Salyut-7 orbital station

    Science.gov (United States)

    Startsev, Oleg V.; Nikishin, Eugene F.

    1995-01-01

    Specimens of polymeric composite materials for aviation and space applications such as glass fiber reinforced plastics (GFRP), carbon fiber reinforced plastics (CFRP), organic fiber reinforced plastics (OFRP), and hybrid plastics (HP) based on epoxy compounds were exposed to the space environment on the surface of Salyut-7 orbital station. The space exposure lasted 1501 days as a maximum. The data relating to the change in mechanical properties, mass losses, glass transition temperature, linear thermal expansion coefficient, and microstructure after various periods of exposure are given. It has been found that the change in properties is caused by the processes of binder postcuring and microerosion of the exposed surface of plastics. The phenomenon of strengthening of the surface layer of hybrid composites, due to which the nature of destruction changes at bending loads, has been revealed.

  5. Standard Test Method for Testing Polymeric Seal Materials for Geothermal and/or High Temperature Service Under Sealing Stress

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1985-01-01

    1.1 This test method covers the initial evaluation of (screening) polymeric materials for seals under static sealing stress and at elevated temperatures. 1.2 This test method applies to geothermal service only if used in conjunction with Test Method E 1068. 1.3 The test fluid is distilled water. 1.4 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. Free-radical polymerization of some dental and medical materials by pulse radiolysis

    International Nuclear Information System (INIS)

    Complete text of publication follows. The extensive use of N-P-tolylglycine (NPG) analogues in adhesive bonding technologies calls for a better understanding of their role in initiating free-radical polymerization. The fast oxidation and reductions of NTG proceed via the formation of various types of free radicals and radical cation and anion intermediates. These intermediates were identified and their reactivity with oxygen, to produce the corresponding peroxyl radicals, has been measured. Hydroxyl radicals (OH) were used to initiate oxidation reactions of NTG, while the reduction reactions were initiated with hydrated electrons (eaq-). In the presence and absence of oxygen, the oxidation reaction mechanism of NTG by OH proceeded predominately by addition to the aromatic ring followed by OH- elimination reactions to produce NTG+ radical cations. In the presence of oxygen, OH-NTG also reacted with oxygen to produce peroxyl radicals. The reduction reaction of NTG with eaq- proceed via addition to the aromatic ring and amine-elimination, to produce various radicals: addition to the aromatic ring was followed by a fast protonation reaction to produce cyclohexadienyl radicals, and the amine-elimination reaction produced acetic acid free radicals and 4-methylaniline. In addition, it was found that the H-atom reaction with NTG also produced radical cations

  7. Property changes induced by the space environment in polymeric materials on LDEF

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, A.F.; Finckenor, M.M.; Kamenetzky, R.R. (NASA, Marshall Space Flight Center, Huntsville, AL (United States))

    1992-01-01

    Property changes that occurred in four groups of polymer-based materials in the Long Duration Exposure Facility (LDEF) due to exposure to the outer space environment for 5.8 yrs are examined. Evaluations of contamination and mass loss are presented along with optical, thermal, and electrical analyses and mechanical property evaluations for TFE Teflon, the fluorinated material Halar, the silicone-based material RTV 511, and PEEK resin. 5 refs.

  8. Property changes induced by the space environment in polymeric materials on LDEF

    International Nuclear Information System (INIS)

    Property changes that occurred in four groups of polymer-based materials in the Long Duration Exposure Facility (LDEF) due to exposure to the outer space environment for 5.8 yrs are examined. Evaluations of contamination and mass loss are presented along with optical, thermal, and electrical analyses and mechanical property evaluations for TFE Teflon, the fluorinated material Halar, the silicone-based material RTV 511, and PEEK resin. 5 refs

  9. Property changes induced by the space environment in polymeric materials on LDEF

    Science.gov (United States)

    Whitaker, Ann F.; Finckenor, Miria M.; Kamenetzky, Rachel R.

    1992-01-01

    Property changes that occurred in four groups of polymer-based materials in the Long Duration Exposure Facility (LDEF) due to exposure to the outer space environment for 5.8 yrs are examined. Evaluations of contamination and mass loss are presented along with optical, thermal, and electrical analyses and mechanical property evaluations for TFE Teflon, the fluorinated material Halar, the silicone-based material RTV 511, and PEEK resin.

  10. Screening-level models to estimate partition ratios of organic chemicals between polymeric materials, air and water.

    Science.gov (United States)

    Reppas-Chrysovitsinos, Efstathios; Sobek, Anna; MacLeod, Matthew

    2016-06-15

    Polymeric materials flowing through the technosphere are repositories of organic chemicals throughout their life cycle. Equilibrium partition ratios of organic chemicals between these materials and air (KMA) or water (KMW) are required for models of fate and transport, high-throughput exposure assessment and passive sampling. KMA and KMW have been measured for a growing number of chemical/material combinations, but significant data gaps still exist. We assembled a database of 363 KMA and 910 KMW measurements for 446 individual compounds and nearly 40 individual polymers and biopolymers, collected from 29 studies. We used the EPI Suite and ABSOLV software packages to estimate physicochemical properties of the compounds and we employed an empirical correlation based on Trouton's rule to adjust the measured KMA and KMW values to a standard reference temperature of 298 K. Then, we used a thermodynamic triangle with Henry's law constant to calculate a complete set of 1273 KMA and KMW values. Using simple linear regression, we developed a suite of single parameter linear free energy relationship (spLFER) models to estimate KMA from the EPI Suite-estimated octanol-air partition ratio (KOA) and KMW from the EPI Suite-estimated octanol-water (KOW) partition ratio. Similarly, using multiple linear regression, we developed a set of polyparameter linear free energy relationship (ppLFER) models to estimate KMA and KMW from ABSOLV-estimated Abraham solvation parameters. We explored the two LFER approaches to investigate (1) their performance in estimating partition ratios, and (2) uncertainties associated with treating all different polymers as a single "bulk" polymeric material compartment. The models we have developed are suitable for screening assessments of the tendency for organic chemicals to be emitted from materials, and for use in multimedia models of the fate of organic chemicals in the indoor environment. In screening applications we recommend that KMA and KMW be

  11. Development of Novel Polymeric Materials for Gene Therapy and pH-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brian Curtis Anderson

    2002-08-27

    The underlying theme of this thesis is the use of polymeric materials in bioapplications. Chapters 2-5 either develop a fundamental understanding of current materials used for bioapplications or establish protocols and procedures used in characterizing and synthesizing novel materials. In chapters 6 and 7 these principles and procedures are applied to the development of materials to be used for gene therapy and drug delivery. Chapter one is an introduction to the ideas that will be necessary to understand the subsequent chapters, as well as a literature review of these topics. Chapter two is a paper that has been published in the ''Journal of Controlled Release'' that examines the mechanism of drug release from a polymer gel, as well as experimental design suggestions for the evaluation of water soluble drug delivery systems. Chapter three is a paper that has been published in the ''Journal of Pharmaceutical Sciences'' that discusses the effect ionic salts have on properties of the polymer systems examined in chapter two. Chapter four is a paper published in the Materials Research Society Fall 2000 Symposium Series dealing with the design and synthesis of a pH-sensitive polymeric drug delivery device. Chapter five is a paper that has been published in the journal ''Biomaterials'' proposing a novel polymer/metal composite for use as a biomaterial in hip arthroplasty surgery. Chapter six is a paper that will appear in an upcoming volume of the Journal ''Biomaterials'' dealing with the synthesis of a novel water soluble cationic polymer with possible applications in non-viral gene therapy. Chapter seven is a paper that has been submitted to ''Macromolecules'' discussing several novel block copolymers based on poly(ethylene glycol) and poly(diethylamino ethyl methacrylate) that possess both pH-sensitive and temperature sensitive properties. Chapter eight contains a

  12. Polymeric near-infrared absorbing dendritic nanogels for efficient in vivo photothermal cancer therapy

    Science.gov (United States)

    Molina, Maria; Wedepohl, Stefanie; Calderón, Marcelo

    2016-03-01

    In recent years, several near-infrared light absorbing inorganic nanomaterials have been developed for photothermal therapy. However, their biological fate after injection limits their clinical utilization. In this work, we developed a novel polymeric near-infrared light absorbing material based on a biocompatible thermoresponsive nanogel that is semi-interpenetrated with polyaniline, a conjugated polymer with strong near-infrared absorbance. This polymeric nanocomposite generates heat after being irradiated by NIR light, thereby inducing a local hyperthermia that is used for photothermal cancer therapy in vitro and in vivo.In recent years, several near-infrared light absorbing inorganic nanomaterials have been developed for photothermal therapy. However, their biological fate after injection limits their clinical utilization. In this work, we developed a novel polymeric near-infrared light absorbing material based on a biocompatible thermoresponsive nanogel that is semi-interpenetrated with polyaniline, a conjugated polymer with strong near-infrared absorbance. This polymeric nanocomposite generates heat after being irradiated by NIR light, thereby inducing a local hyperthermia that is used for photothermal cancer therapy in vitro and in vivo. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07587d

  13. Applicability of the modified XPP model to a description of flow behaviour of polymeric materials

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Radek; Filip, Petr; Zelenková, Jana

    Vol. 1662. Melville : AIP Publishing, 2015 - (Zatloukal, M.), 020004-1-020004-14 ISBN 978-0-7354-1306-1. [Novel Trends in Rheology /6./. Zlín (CZ), 28.07.2015-29.07.2015] Institutional support: RVO:67985874 Keywords : XPP model * rheological properties * Leonov model * LDPE materials * HDPE materials Subject RIV: BK - Fluid Dynamics

  14. Novel functionalized polymeric fabric and fiber material as solid support for solid-phase synthesis and biomedical applications

    Science.gov (United States)

    Xiang, Bei

    The aim of the research is to develop novel polymer solid support by modifying or fabricating polymeric fibrous materials for peptide synthesis and biomedical applications. Originally chemical inert isotactic polypropylene (iPP) fabric was utilized and modified to serve as a functional flexible planar solid support for solid phase peptide synthesis. The modification was achieved through thermal initiated radical grafting polymerization using acrylic acid, poly (ethylene glycol) diacrylate as monomers, and benzoyl peroxide as radical initiator. The iPP fabric was successfully functionalized and possessing as high as 0.7mmol/g carboxylic acid groups. Peptide ligand LHPQF was successfully synthesized on the new functional planar support. Specific enzyme immobilization was fulfilled on the functional iPP fabric support. A commercially available ethylene-acrylic acid copolymer was made into ultrafine copolymer fiber bundles which are composed of nanofibers with diameters ranging from 200nm to 800nm. Various mixing ratios of copolymer/matrix materials were utilized to explore the effect on the final nanofiber physical properties including morphology and stability in solvents. The surface carboxylic acid groups were further converted to amino groups before the functional nanofibers can be applied in solid phase peptide synthesis. Two peptide ligands, LHPQF and HWRGWV, were also successfully synthesized on the nanofiber bundles. Streptavidin and human immunoglobulin G specific binding with the corresponding ligand which was anchored on the nanofibers was conducted successfully to illustrate the potential applications of the nanofiber materials in biomedical field. Further study on the dispersion of the ethylene-acrylic acid nanofiber bundles was pursued to take advantage of the super high active surface area of functional nanofibers. To manipulate the polymer nanofibers during synthesis and bio-assays, a technique was developed to controllably assemble and disperse the

  15. Ternary europium mesoporous polymeric hybrid materials Eu({beta}-diketonate){sub 3}pvpd-SBA-15(16): host-guest construction, characterization and photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Gu Yanjing [Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092 (China); Yan Bing, E-mail: byan@tongji.edu.cn [Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092 (China); Li Yanyan [Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092 (China)

    2012-06-15

    Novel organic-inorganic mesoporous luminescent polymeric hybrid materials containing europium(III) complexes incorporated to mesoporous silica SBA-15/SBA-16 have been prepared by simple physical doping (impregnation) methods, followed by the addition polymerization reaction of the monomer 4-vinylpyridine (vpd) extending along the mesoporous channels. The precursor europium(III) complexes are synthesized by {beta}-diketonate ({beta}-diketonate=2-thenoyltrifluoroacetonate (tta), hexafluoroacetylacetonate (hfac), trifluoroacetylacetonate (taa)) and monomer 4-vinylpyridine (vpd) coordinated to Eu{sup 3+}, and SBA-15/SBA-16 are obtained via a sol-gel process. After the physical doping and the polymerization reaction, the final ternary materials Eu({beta}-diketonate){sub 3}pvpd-SBA-15/Eu({beta}-diketonate){sub 3}pvpd-SBA-16 ({beta}-diketonate=tta, hfac, taa) are received. The physical properties and espeically the photoluminescence of these hybrids are characterized, and the XRD and BET results reveal that all of these hybrid materials have uniformity in the mesostructure. The detailed luminescence investigation on all the materials show that Eu(tta){sub 3}pvpd-SBA-16 have the highest luminescence intensity and the materials with taa ligands have longer lifetimes. - Grapical abstract: Luminescent mesoporous polymeric hybrid materials containing europium complexes hydrogen bonding to silica SBA-15/SBA-16 followed by the addition polymerization reaction of 4-vinylpyridine (vpd) extending along the mesoporous channels. Highlights: Black-Right-Pointing-Pointer Functional mesoporous with simple impregnation method. Black-Right-Pointing-Pointer New lanthanide mesoporous hybrids with polymer ligands. Black-Right-Pointing-Pointer Luminescence in visible region.

  16. Preparation, characterization and thermal properties of nanocapsules containing phase change material n-dodecanol by miniemulsion polymerization with polymerizable emulsifier

    International Nuclear Information System (INIS)

    Highlights: ► We prepare nanocapsules containing n-dodecanol via miniemulsion polymerization. ► Polymerizable emulsifier plays important role in the preparation of nanocapsules. ► Adding co-emulsifier into water phase is helpful to encapsulate n-dodecanol. ► The phase change latent heat of nanocapsule is 98.8 J/g with temperature of 18.2 °C. -- Abstract: Nanocapsules containing phase change material (PCM) n-dodecanol as core and polymethyl methacrylate (PMMA) as shell were synthesized by miniemulsion polymerization with polymerizable emulsifier DNS-86 and co-emulsifier hexadecane (HD). The nanocapsules were characterized by using Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and laser particle diameter analyzer. The effects of polymerizable emulsifier and co-emulsifier on the properties of nanocapsules were studied. The results show that thermal properties of nanocapsules are affected greatly by the addition methods of HD and the amounts of DNS-86 and HD. Adding HD into water phase is helpful for the encapsulation of n-dodecanol. When the mass ratios of DNS-86 to n-dodecanol and the mass ratios of HD to n-dodecanol were 3% and 2%, the phase change latent heat and the encapsulation efficiency of nanocapsules reached to the maximum value of 98.8 J/g and 82.2%, respectively. Spherical nanocapsules with mean diameter of 150 nm and phase change temperature of 18.2 °C are obtained, which are sure to have a good potential for energy storage.

  17. Characterization of aluminosilicate nanoparticles as a reinforcement in composite materials based on polymeric matrix

    Directory of Open Access Journals (Sweden)

    M. Staszuk

    2012-12-01

    Full Text Available Purpose: of this paper is to characterised MMT particles as a reinforcement in polyethylene based composite material and determine its influence on the mechanical properties of obtained materials.Design/methodology/approach: Within the framework of experiment there has been produced composite materials based on polyethylene with 1 wt%,3 wt% and 5 wt% content of montmorillonite using injection moulding method.Findings: Influence of the montmorillonite additive on polyethylene properties.Research limitations/implications: Presented method of composite preparation leads to microcomposite materials, it does not enable intercalation or exfoliation of silicate nanofiller.Originality/value: The obtained investigation results confirm the relation between amount of introduced montmorillonite and hardness as well as strength properties of composites. Properties are better up to some content, strictly defined and equal to 4-5 wt%, and then get worse.

  18. Aging of polymers due to ionizing radiation as investigated on some polymeric electrical insulating materials

    International Nuclear Information System (INIS)

    The reliability of the qualifying procedures suggested by international standards relating to accelerated aging tests on commercial organic electrical insulating materials has been evaluated. Several types of ethylene-propylene rubbers (EPR) and cycloaliphatic epoxy resin (EP), widely used as electrical insulating materials have been evaluated. Several types of EPR and EP used in nuclear power plants have been gamma-irradiated under conditions of different total dose and different irradiation intensity. In the case of EPRs, the effect of irradiation has been evaluated on the basis of tensile tests, whereas in the case of EP resin - from the changes in glass transition temperature. Under the action of gamma radiation both crosslinking and degradation take place and the dependence of these two processes on the irradiation parameters (dose and dose intensity) differs for various materials. It is therefore important to individuate the testing conditions for each kind of insulating material. (author)

  19. Space Station Validation of Advanced Radiation-Shielding Polymeric Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In Subtopic X11-01, NASA has identified the need to develop advanced radiation-shielding materials and systems to protect humans from the hazards of space radiation...

  20. Space Station Validation of Advanced Radiation-Shielding Polymeric Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In Subtopic X11.01, NASA has identified the need to develop advanced radiation-shielding materials and systems to protect humans from the hazards of space radiation...

  1. Bacterial Attachment to Polymeric Materials Correlates with Molecular Flexibility and Hydrophilicity

    OpenAIRE

    Sanni, Olutoba; Chang, Chien-Yi; Anderson, Daniel G.; Langer, Robert; Davies, Martyn C.; Williams, Philip M; Williams, Paul; Alexander, Morgan R.; Hook, Andrew L.

    2014-01-01

    A new class of material resistant to bacterial attachment has been discovered that is formed from polyacrylates with hydrocarbon pendant groups. In this study, the relationship between the nature of the hydrocarbon moiety and resistance to bacteria is explored, comparing cyclic, aromatic, and linear chemical groups. A correlation is shown between bacterial attachment and a parameter derived from the partition coefficient and the number of rotatable bonds of the materials' pendant groups. This...

  2. Experimental Beam Studies of Plasma-generated Species Interaction with Polymeric Materials and Biomolecules

    OpenAIRE

    Chung, Ting-Ying

    2012-01-01

    Low temperature plasma-based processes are used extensively in many modern technologies. It is thus very important to understand plasma and surface interactions in order to improve plasma processes and design of functional materials. Applying a high vacuum beam system, this dissertation studies the fundamental mechanisms of plasma species-induced modification of materials for two critical applications: manufacturing of semiconductor devices and surface deactivation of infectious biomolecules....

  3. Evaluation of ceramic and polymeric materials for use in engineered barrier systems

    International Nuclear Information System (INIS)

    Ceramic materials evaluated in the screening studies were Al2O3 (99.8%), mullite, vitreous silica, BaTiO3, CaTiO3, CaZrO3, CaTiSiO5, TiO2, ZrSiO4, basalt, Pyroceram 9617, and Marcor code 9658 machinable glass ceramic. One grade of graphite (Toyotanso IB-11) was also evaluated. Demineralized water, a synthetic Hanford groundwater, and a synthetic NaCl brine solution were used in the screening tests. Demineralized water was used in all five of the leach tests, but the other solutions were only used in the static leach tests at 150 and 2500C. Based on the results obtained, graphite appears to be the most leach resistant of the materials tested with the two grades of alumina being the best of the ceramic materials. Titanium dioxide and ZrO2 are the most leach resistant of the remaining materials. Candidate materials from all three general classes of polymers (thermoplastics, thermosets, and elastomers) were considered in the selection of materials. Selected groups of polymers were tested in the flowing autoclave at 150, 200, and 2500C with some polymers being further tested at the next higher temperature. Next, selected samples were exposed to gamma radiation. These samples were then submitted for tensile and elongation measurements. Selected samples which appeared promising from both autoclave and radiation testing were further evaluated by impact tests. The materials that appeared most promising after autoclave testing were the EPDM rubbers, polyphenylene sulfide, poly(ethylene-tetrafluoroethylene) copolymer, and polyfurfuryl alcohol. The radiation dose had little effect on polyfurfuryl alcohol and polyphenylene sulfide samples; very significant decreases in elongation were observed for the fluorocarbon copolymer and the EPDM rubbers. While the polyphenylene sulfide and polyfurfuryl alcohol showed little change in impact strength, poly(ethylene-tetrafluoroethylene) decreased in impact strength

  4. Biocompatibility of polyaniline

    Czech Academy of Sciences Publication Activity Database

    Humpolíček, P.; Kašpárková, V.; Saha, P.; Stejskal, Jaroslav

    2012-01-01

    Roč. 162, 7/8 (2012), s. 722-727. ISSN 0379-6779 R&D Projects: GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : conducting polymer * polyaniline * biocompatibility Subject RIV: BK - Fluid Dynamics Impact factor: 2.109, year: 2012

  5. A espectrometria atômica e a determinação de elementos metálicos em material polimérico Atomic spectrometry and the determination of metals in polymeric materials

    Directory of Open Access Journals (Sweden)

    Solange Cadore

    2008-01-01

    Full Text Available Polymeric materials are widely used in the chemical industry and are part of our daily lives. Inorganic species may be added to them as additives, anti-oxidizing agents, stabilizers, plasticizers, colorants and catalysts and may be present in a wide range of concentrations. Their determination demands the development of analytical methods considering different kinds of polymeric materials, their composition and the final use of the material. Although many different analytical techniques may be used, this review emphasizes those based on atomic absorption and emission spectrometry. Solid sampling techniques and digestion methods are described and discussed and compared considering published results.

  6. Biodegradable Shape Memory Polymeric Material from Epoxidized Soybean Oil and Polycaprolactone

    Directory of Open Access Journals (Sweden)

    Takashi Tsujimoto

    2015-10-01

    Full Text Available This article deals with the synthesis of plant oil-based shape memory materials from epoxidized soybean oil (ESO and polycaprolactone (PCL. PolyESO/PCLs were synthesized by an acid-catalyzed curing in the presence of PCL. During the reaction, PCL scarcely reacted with ESO and the crystallinity of the PCL component decreased to form a semi-interpenetrating network structure. The incorporation of the PCL components improved the maximum stress and strain at break of ESO-based network polymer. The polyESO/PCL was gradually degraded by Pseudomonas cepasia lipase. Furthermore, the polyESO/PCLs exhibited excellent shape memory properties, and the strain fixity depended on the feed ratio of ESO and PCL. The shape memory-recovery behaviors were repeatedly practicable. The resulting materials are expected to contribute to the development of biodegradable intelligent materials.

  7. Evaluation of the Biocompatibility of Poly (ortho ester), Copolymer of ε-caprolactone/D,L-lactide and the Composite of Copolymer of ε-caprolactone/D,L-lactide and Tricalciumphosphate as Bone Filling Material

    OpenAIRE

    Ekholm, Marja

    2006-01-01

    The purpose of this series of studies was to evaluate the biocompatibility of poly (ortho) ester (POE), copolymer of ε-caprolactone and D,L-lactide [P (ε-CL/DL-LA)] and the composite of P(ε-CL/DL-LA) and tricalciumphosphate (TCP) as bone filling material in bone defects. Tissue reactions and resorption times of two solid POE-implants (POE 140 and POE 46) with different methods of sterilization (gamma- and ethylene oxide sterilization), P(ε-CL/DL-LA)(40/60 w/w) in paste form and 50/50 w/w ...

  8. Does long term exposure to radon gas influence the properties of polymeric waterproof materials?

    International Nuclear Information System (INIS)

    The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria. - Highlights: • Long-term exposure of waterproof materials to radon and soil bacteria. • Changes in mechanical properties shown. • Major changes in diffusion coefficient of radon found for PVC

  9. Nonlinear Optical Properties of Organic and Polymeric Thin Film Materials of Potential for Microgravity Processing Studies

    Science.gov (United States)

    Abdeldayem, Hossin; Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin; Witherow, William K.; Bank, Curtis; Shields, Angela; Hicks, Rosline; Ashley, Paul R.

    1996-01-01

    In this paper, we will take a closer look at the state of the art of polydiacetylene, and metal-free phthalocyanine films, in view of the microgravity impact on their optical properties, their nonlinear optical properties and their potential advantages for integrated optics. These materials have many attractive features with regard to their use in integrated optical circuits and optical switching. Thin films of these materials processed in microgravity environment show enhanced optical quality and better molecular alignment than those processed in unit gravity. Our studies of these materials indicate that microgravity can play a major role in integrated optics technology. Polydiacetylene films are produced by UV irradiation of monomer solution through an optical window. This novel technique of forming polydiacetylene thin films has been modified for constructing sophisticated micro-structure integrated optical patterns using a pre-programmed UV-Laser beam. Wave guiding through these thin films by the prism coupler technique has been demonstrated. The third order nonlinear parameters of these films have been evaluated. Metal-free phthalocyanine films of good optical quality are processed in our laboratories by vapor deposition technique. Initial studies on these films indicate that they have excellent chemical, laser, and environmental stability. They have large nonlinear optical parameters and show intrinsic optical bistability. This bistability is essential for optical logic gates and optical switching applications. Waveguiding and device making investigations of these materials are underway.

  10. Toward polymeric materials with optoelectronic properties tunable by mechanical and optical stimuli

    Science.gov (United States)

    Harvey, Christopher P.

    Stimuli responsive materials have properties that can be reversibly altered through treatment with a controllable external factor such as heat, light, or mechanical force. The work presented herein was focused on creating materials with optoelectronic properties tunable through mechanical stress or light irradiation. The optical properties of mechanochromic systems change under mechanical stress. There are several ways of achieving this response. Physical deformation may disrupt electronic interactions that have been established within the material or it may change the spatial arrangement of internal components in such a way as to alter their interaction with light. Breaking and reestablishing pi-pi interactions between conjugated units within elastic polymers may also lead to a mechanochromic response. Systems which respond to deformation with reversible, visible color changes may be useful for stress detection within materials. Segmented polyurethanes are elastomers composed of amorphous, saturated chain soft segments and rigid, more crystalline hard domains. Within aggregates of hard domains pi-pi interactions may form and result in alteration of the optoelectronic properties of the system. These electronic interactions may be disrupted by mechanical deformation leading to an observable mechanochromic response. A series of oligothiophene diols and diamines, as well as a naphthalene diimide diol, have been synthesized for incorporation into the hard domains of segmented polyurethanes and polyureas using long poly(tetramethylene oxide) chains as soft segments in order to evaluate such systems for possible mechanochromic response. Photochromic molecules undergo reversible changes in properties in response to irradiation with light. These compounds are found in a variety of natural pigment systems and organic electronic applications. The observed changes in properties are the results of rearrangements within the molecules which alter their optoelectronic

  11. Effect of time-dependent material properties on the crack behavior in the interface of two polymeric materials

    Czech Academy of Sciences Publication Activity Database

    Zouhar, Michal; Hutař, Pavel; Náhlík, Luboš; Knésl, Zdeněk

    2011-01-01

    Roč. 47, č. 2 (2011), s. 203-210. ISSN 0191-5665 R&D Projects: GA ČR GC101/09/J027; GA ČR GD106/09/H035; GA ČR GA106/09/0279 Institutional research plan: CEZ:AV0Z20410507 Keywords : multilayer plastic pipes * bimaterial interface * stability criteria * critical stress * time-depended material properties Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.409, year: 2011

  12. Biocompatible composites of ultrahigh molecular weight polyethylene

    Science.gov (United States)

    Panin, S. V.; Kornienko, L. A.; Suan, T. Nguen; Ivanova, L. P.; Korchagin, M. A.; Chaikina, M. V.; Shilko, S. V.; Pleskachevskiy, Yu. M.

    2015-10-01

    Mechanical and tribotechnical characteristics of biocompatible, antifriction and extrudable composites based on ultrahigh molecular weight polyethylene (UHMWPE) as well as hybrid matrix "UHMWPE + PTFE" with biocompatible hydroxyapatite filler under the dry friction and boundary lubrication were investigated. A comparative analysis of effectiveness of adding the hydroxyapatite to improve the wear resistance of composites based on these two matrices was performed. It is shown that the wear intensity of nanocomposites based on the hybrid matrix is lower than that for the composites based on pure UHMWPE. Possibilities of using the composites of the polymer "UHMWPE-PTFE" mixture as a material for artificial joints implants are discussed.

  13. Bacterial attachment to polymeric materials correlates with molecular flexibility and hydrophilicity.

    Science.gov (United States)

    Sanni, Olutoba; Chang, Chien-Yi; Anderson, Daniel G; Langer, Robert; Davies, Martyn C; Williams, Philip M; Williams, Paul; Alexander, Morgan R; Hook, Andrew L

    2015-04-01

    A new class of material resistant to bacterial attachment has been discovered that is formed from polyacrylates with hydrocarbon pendant groups. In this study, the relationship between the nature of the hydrocarbon moiety and resistance to bacteria is explored, comparing cyclic, aromatic, and linear chemical groups. A correlation is shown between bacterial attachment and a parameter derived from the partition coefficient and the number of rotatable bonds of the materials' pendant groups. This correlation is applicable to 86% of the hydrocarbon pendant moieties surveyed, quantitatively supporting the previous qualitative observation that bacteria are repelled from poly(meth)acrylates containing a hydrophilic ester group when the pendant group is both rigid and hydrophobic. This insight will help inform and predict the further development of polymers resistant to bacterial attachment. PMID:25491266

  14. Strategies for the Conversion of Lignin to High-Value Polymeric Materials: Review and Perspective.

    Science.gov (United States)

    Upton, Brianna M; Kasko, Andrea M

    2016-02-24

    The majority of commodity plastics and materials are derived from petroleum-based chemicals, illustrating the strong dependence on products derived from non-renewable energy sources. As the most accessible, renewable form of carbon (in comparison to CO2), lignocellulosic biomass (defined as organic matter available on a renewable basis) has been acknowledged as the most logical carbon-based feedstock for a variety of materials such as biofuels and chemicals. This Review focuses on methods developed to synthesize polymers derived from lignin, monolignols, and lignin-derived chemicals. Major topics include the structure and processing of lignocellulosic biomass to lignin, polymers utilizing lignin as a macromonomer, synthesis of monomers and polymers from monolignols, and polymers from lignin-derived chemicals, such as vanillin. PMID:26654678

  15. Biodegradable Shape Memory Polymeric Material from Epoxidized Soybean Oil and Polycaprolactone

    OpenAIRE

    Takashi Tsujimoto; Takeshi Takayama; Hiroshi Uyama

    2015-01-01

    This article deals with the synthesis of plant oil-based shape memory materials from epoxidized soybean oil (ESO) and polycaprolactone (PCL). PolyESO/PCLs were synthesized by an acid-catalyzed curing in the presence of PCL. During the reaction, PCL scarcely reacted with ESO and the crystallinity of the PCL component decreased to form a semi-interpenetrating network structure. The incorporation of the PCL components improved the maximum stress and strain at break of ESO-based network polymer. ...

  16. New Alkaline-Earth Polymeric Frameworks as green materials for sorption and heterogeneous catalysis

    OpenAIRE

    Platero Prats, Ana Eva

    2011-01-01

    Metal-Organic Frameworks (or MOFs) are porous organic-inorganic crystalline materials in which the metallic centers are joined through organic ligands via coordination bonds to give frameworks with different dimensionalities. The work presented in this thesis is focused on the obtaining of new MOFs using alkaline-earth elements as metal centers, which could represent a comparatively cheap, nontoxic and green alternative to conventional MOFs based on transition metals or rare-earth elements.Th...

  17. Finite element analysis of the high strain rate testing of polymeric materials

    Science.gov (United States)

    Gorwade, C. V.; Alghamdi, A. S.; Ashcroft, I. A.; Silberschmidt, V. V.; Song, M.

    2012-08-01

    Advanced polymer materials are finding an increasing range of industrial and defence applications. Ultra-high molecular weight polymers (UHMWPE) are already used in lightweight body armour because of their good impact resistance with light weight. However, a broader use of such materials is limited by the complexity of the manufacturing processes and the lack of experimental data on their behaviour and failure evolution under high-strain rate loading conditions. The current study deals with an investigation of the internal heat generation during tensile of UHMWPE. A 3D finite element (FE) model of the tensile test is developed and validated the with experimental work. An elastic-plastic material model is used with adiabatic heat generation. The temperature and stresses obtained with FE analysis are found to be in a good agreement with the experimental results. The model can be used as a simple and cost effective tool to predict the thermo-mechanical behaviour of UHMWPE part under various loading conditions.

  18. Does long term exposure to radon gas influence the properties of polymeric waterproof materials?

    Science.gov (United States)

    Navratilova Rovenska, Katerina; Jiranek, Martin; Kokes, Pavel; Wasserbauer, Richard; Kacmarikova, Veronika

    2014-01-01

    The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria.

  19. REVIEW: CHITOSAN BASED HYDROGEL POLYMERIC BEADS – AS DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    Manjusha Rani

    2010-11-01

    Full Text Available Chitosan obtained by alkaline deacetylation of chitin is a non-toxic, biocompatible, and biodegradable natural polymer. Chitosan-based hydrogel polymeric beads have been extensively studied as micro- or nano-particulate carriers in the pharmaceutical and medical fields, where they have shown promise for drug delivery as a result of their controlled and sustained release properties, as well as biocompatibility with tissue and cells. To introduce desired properties and enlarge the scope of the potential applications of chitosan, graft copolymerization with natural or synthetic polymers on it has been carried out, and also, various chitosan derivatives have been utilized to form beads. The desired kinetics, duration, and rate of drug release up to therapeutical level from polymeric beads are limited by specific conditions such as beads material and their composition, bead preparation method, amount of drug loading, drug solubility, and drug polymer interaction. The present review summarizes most of the available reports about compositional and structural effects of chitosan-based hydrogel polymeric beads on swelling, drug loading, and releasing properties. From the studies reviewed it is concluded that chitosan-based hydrogel polymeric beads are promising drug delivery systems.

  20. Charge recombination in distributed heterostructures of semiconductor discotic and polymeric materials.

    Science.gov (United States)

    Clark, Jenny; Archer, Robert; Redding, Tim; Foden, Clare; Tant, Julien; Geerts, Yves; Friend, Richard H.; Silva, Carlos

    2008-06-01

    Control of microstructure and energetics at heterojunctions in organic semiconductors is central to achieve high light-emitting or photovoltaic device efficiency. We report the observation of an emissive exciplex formed between an electron-accepting discotic material (hexaazatrinaphthylene or HATNA-SC12) and a hole accepting conjugated polymer {poly[9,9- dioctylfluorene-co-N-(4-butylphenyl)diphenylamine] or TFB}. In contrast to polymer-polymer systems, we find here that the exciplex is strongly localized at the interface, acting as an energy bottleneck with inefficient transfer to bulk exciton states and with low yield of charge separation.

  1. DNA-nanoparticle assemblies go organic: Macroscopic polymeric materials with nanosized features

    OpenAIRE

    Mentovich Elad D; Livanov Konstantin; Prusty Deepak K; Sowwan Mukules; Richter Shachar

    2012-01-01

    Abstract Background One of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materi...

  2. Multilayer radar absorbing material processing by using polymeric nonwoven and conducting polymer

    Directory of Open Access Journals (Sweden)

    Luiza de Castro Folgueras

    2008-09-01

    Full Text Available This study shows the processing of radar absorbing multilayer structures based on nonwoven substrates of polyacrylonitrile and poly (ethylene terephthalate impregnated with a polyaniline and polyurethane mixture. Processed materials with different parameters - layer stacking and impregnated faces - were evaluated considering the incident radiation attenuation in the frequency range of 8 to 12 GHz. The results show the influence of the quantity, types and thickness of the impregnated layers. Scanning electronic microscopy observations evaluated the anchorage of the absorbing center (polyaniline in the substrate. In a general way, the different obtained structures presented incident radiation attenuation values between 87 and 99%. This result allows its use as microwave absorbers.

  3. Dependence of contact electrification on the magnitude of strain in polymeric materials

    Science.gov (United States)

    Sow, Mamadou; Lacks, Daniel J.; Mohan Sankaran, R.

    2012-10-01

    We present a new experimental approach to systematically study the effect of material strain on contact electrification. Thin sheets of latex rubber are variably strained by stretching over a hollow cylinder, analogous to a drum. The strained sheets are repeatedly contacted with another surface by a computer-controlled apparatus. The surface potential on the latex rubber is measured in real time by a non-contact electrostatic voltmeter. For unstrained latex rubber, we find that contact with polytetrafluoroethylene (PTFE) leads to a negative surface potential that progressively increases in magnitude to more negative values with increasing number of contacts. When the latex rubber is strained, contact with PTFE causes the surface potential of the latex rubber to shift to less negative values. At strains of more than ˜50%, the polarity of the surface potential is reversed, such that contact with PTFE causes the latex rubber to charge positively. These results indicate that contact electrification intimately depends on the degree of material strain, and may explain how spatial inhomogeneities of charge exist on contacted surfaces and why there is a lack of reproducibility in contact charging experiments.

  4. The Biocompatibility of Wool Keratin

    Institute of Scientific and Technical Information of China (English)

    LIU Mei; YU Wei-dong; WANG Xue-lei

    2007-01-01

    Keratin is the major structural fibrous protein providing outer covering such as hair, wool, feathers, etc. When being used as a kind of biomaterials, the biocompatibility of wool keratin is one of the most critical questions. By now, there has not been systemic study on the biocompatibiiity of keratin. Therefore, in this article we used the procedures of skin irritation, haemolysis and subcutaneous implantation according to ISO 10993 to study it. Moreover, the Fourier transform-infrared (FTIR) spectroscopy was utilized to analyse the impurity and structure modification of wool keratin film. The part of the animal tests showed that the wool keratin films prepared by authors were biocompatible. But the residual of sodium dodecyi sulfate (SDS) affected the results of other tests. Consequently, the wool keratin membrane is one kind of favourable and promising biomaterial for biomedical and histological utilization. The residual SDS used as an agent should be eliminated from the keratin solution or membrane completely if for biological usage. In conclusion, wool keratin, as a kind of natural protein, prospectively could be applied in biomedical materials and scaffolds of tissue engineering.

  5. Biocompatibility of plasma nanostructured biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Slepičková Kasálková, N. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Bačáková, L. [Institute of Physiology, Academy of Sciences of the Czech Republic 142 20 Prague (Czech Republic); Sajdl, P. [Department of Power Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

    2013-07-15

    Many areas of medicine such as tissue engineering requires not only mastery of modification techniques but also thorough knowledge of the interaction of cells with solid state substrates. Plasma treatment can be used to effective modification, nanostructuring and therefore can significantly change properties of materials. In this work the biocompatibility of the plasma nanostructured biopolymers substrates was studied. Changes in surface chemical structure were studied by X-ray photoelectron spectroscopy (XPS). The morphology pristine and modified samples were determined using atomic force microscopy (AFM). The surface wettability was determined by goniometry from contact angle. Biocompatibility was determined by in vitro tests, the rat vascular smooth muscle cells (VSMCs) were cultivated on the pristine and plasma modified biopolymer substrates. Their adhesion, proliferation, spreading and homogeneous distribution on polymers was monitored. It was found that the plasma treatment leads to rapid decrease of contact angle for all samples. Contact angle decreased with increasing time of modification. XPS measurements showed that plasma treatment leads to changes in ratio of polar and non-polar groups. Plasma modification was accompanied by a change of surface morphology. Biological tests found that plasma treatment have positive effect on cells adhesion and proliferation cells and affects the size of cell’s adhesion area. Changes in plasma power or in exposure time influences the number of adhered and proliferated cells and their distribution on biopolymer surface.

  6. Biocompatibility of plasma nanostructured biopolymers

    International Nuclear Information System (INIS)

    Many areas of medicine such as tissue engineering requires not only mastery of modification techniques but also thorough knowledge of the interaction of cells with solid state substrates. Plasma treatment can be used to effective modification, nanostructuring and therefore can significantly change properties of materials. In this work the biocompatibility of the plasma nanostructured biopolymers substrates was studied. Changes in surface chemical structure were studied by X-ray photoelectron spectroscopy (XPS). The morphology pristine and modified samples were determined using atomic force microscopy (AFM). The surface wettability was determined by goniometry from contact angle. Biocompatibility was determined by in vitro tests, the rat vascular smooth muscle cells (VSMCs) were cultivated on the pristine and plasma modified biopolymer substrates. Their adhesion, proliferation, spreading and homogeneous distribution on polymers was monitored. It was found that the plasma treatment leads to rapid decrease of contact angle for all samples. Contact angle decreased with increasing time of modification. XPS measurements showed that plasma treatment leads to changes in ratio of polar and non-polar groups. Plasma modification was accompanied by a change of surface morphology. Biological tests found that plasma treatment have positive effect on cells adhesion and proliferation cells and affects the size of cell’s adhesion area. Changes in plasma power or in exposure time influences the number of adhered and proliferated cells and their distribution on biopolymer surface

  7. Modulating calcium phosphate formation using CO2 laser engineering of a polymeric material

    International Nuclear Information System (INIS)

    The use of simulated body fluid (SBF) is widely used as a screening technique to assess the ability of materials to promote calcium phosphate formation. This paper details the use of CO2 laser surface treatment of nylon® 6,6 to modulate calcium phosphate formation following immersion in SBF for 14 days. Through white light interferometry (WLI) it was determined that the laser surface processing gave rise to maximum Ra and Sa parameters of 1.3 and 4.4 μm, respectively. The use of X-ray photoelectron spectroscopy (XPS) enabled a maximum increase in surface oxygen content of 5.6%at. to be identified. The laser-induced surface modifications gave rise to a modulation in the wettability characteristics such that the contact angle, θ, decreased for the whole area processed samples, as expected, and increased for the patterned samples. The increase in θ can be attributed to a transition in wetting nature to a mixed-state wetting regime. It was seen for all samples that calcium phosphate formed on each surface following 14 days. The largest increase in mass, Δg, owed to calcium phosphate formation, was brought about by the whole area processed sample irradiated with a fluence of 51 J cm−2. No correlation between the calcium phosphate formation and the laser patterned surface properties was determined due to the likely affect of the mixed-state wetting regime. Strong correlations between θ, the surface energy parameters and the calcium phosphate formation for the whole area processed samples allow one to realize the potential for this surface treatment technique in predicting the bone forming ability of laser processed materials. - Highlights: ► Surface modifications brought about a modulation in the wetting of nylon 6,6. ► An increase in θ can be attributed to a mixed-state wetting regime. ► Laser surface treatment modulated the ability to promote apatite formation. ► Mixed-state wetting regime affected the promotion of uniform apatite formation. ► Method

  8. Preliminary study on different technological tools and polymeric materials towards superhydrophobic surfaces for automotive applications

    Science.gov (United States)

    Pruna, A.; Ramiro, J.; Belforte, L.

    2013-11-01

    Nature-inspired fabrication of micro-structured superhydrophobic plastic film was aimed in this work in order to achieve smart materials with self-cleaning properties. Replicas of silicon masters were fabricated from different mixtures of base elements and by different processes. Corresponding microstructures were investigated by contact angle measurements, scanning electron microscopy and spectrophotometric analysis. Independently of the technology employed, the obtained films exhibited high contact angle value (larger than 150°), but while the acrylic polymers presented strong demoulding drawbacks, the polydimethylsiloxane (PDMS) films had good properties in terms of both contact angle and optical transparency. The results showed that most of the patterns realized by replica moulding and hot-embossing (on PDMS and polypropylene (PP), respectively) produced superhydrophobic self-cleaning surfaces.

  9. Noble metal nanoparticles embedding into polymeric materials: From fundamentals to applications.

    Science.gov (United States)

    Prakash, Jai; Pivin, J C; Swart, H C

    2015-12-01

    This review covers some key concepts related to embedding of the noble metal nanoparticles in polymer surfaces. The metal nanoparticles embedded into the polymer matrix can provide high-performance novel materials that find applications in modern nanotechnology. In particular, the origin of various processes that drive the embedding phenomenon, growth of the nanostructure at the surface, factors affecting the embedding including role of surface, interface energies and thermodynamic driving forces with emphasis on the fundamental and technological applications, under different conditions (annealing and ion beams) have been discussed. In addition to the conventional thermal process for embedding which includes the measure of fundamental polymer surface properties with relevant probing techniques, this review discusses the recent advances carried out in the understanding of embedding phenomenon starting from thin metal films to growth of the nanoparticles and embedded nanostructures using novel ion beam techniques. PMID:26584861

  10. AC Analysis of PEO10LiCF3SO3 Polymeric Material for Memory Storage Application

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Iskandarani

    2010-01-01

    Full Text Available Problem statement: Intelligent systems that need to accurately represent human brain requires analogue devices such as a neural switch that processes decision signals and can actually remember the made decision. Polymeric material such as PEO10LiCF3SO3, which previously used in high energy, long life storage batteries, is used here to implement the principle of storage with the required analogue memory. Approach: A number of PEO10LiCF3SO3 devices tested in a controlled environment and their impedance response to both frequency and temperature recorded, analyzed and plotted for interpretation. Results: The tested devices showed ability for charge storage due to its variable impedance response at a range of frequencies, while sustaining very high impedance at DC. The device response found to be affected by intermediate temperatures, with symmetrical response at both low, mid and high temperatures. Conclusion: The designed and tested device showed promising characteristics in terms of memory storage as a neural switch. Its high impedance at DC and low impedance at high frequencies with logarithmic response represented the desired features in a reprogrammable analogue device.

  11. Biocompatibility of polyaniline

    Czech Academy of Sciences Publication Activity Database

    Humpolíček, P.; Kašpárková, V.; Stejskal, Jaroslav; Sáha, P.; Kuceková, Z.

    Prague : Institute of Macromolecular Chemistry AS CR, 2011. s. 129. ISBN 978-80-85009-69-9. [Prague Meeting on Macromolecules /75./ - Conducting Polymers - Formation, Structure, Properties, and Applications. 10.07.2011-14.07.2011, Prague] R&D Projects: GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyaniline * biocompatibility Subject RIV: BK - Fluid Dynamics

  12. Biocompatibility of Niobium Coatings

    OpenAIRE

    René Olivares-Navarrete; Jhon Jairo Olaya; Claudia Ramírez; Sandra Elizabeth Rodil

    2011-01-01

    Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS) substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainles...

  13. The use of radiation-induced graft polymerization for obtaining polymeric biomaterial on the basis of preparation 'Piyavit'

    International Nuclear Information System (INIS)

    The purpose of the present study is to obtain hemocompatible polymeric materials. The method of modification of polymer surface have been elaborated using the radiation-induced graft polymerization after which the surface is capable of coupling with the biologically active substances (BAS) produced from the medicinal leeches. At the Biological Department of Lomonosov Moscow State University was created a medicinal preparation 'Piyavit' isolated from the salivary glands secretion of the medicinal leeches (Hirudo medicinalis). It possess a wide spectrum of biological action on the human organism thanks to the presence of an unique complex natural of BAS (enzymes, inhibitors of proteolityc ensymes, prostanoids and et. al) guaranteed the anticoagulating, thrombolytic, antithrombotic, antiphlogistic, antiatherosclerotic, hypotentic effects and et al.. It has several advantages over anticoagulant heparin which is widely used for above mentioned purpose. 'Piyavit' is the multifunctional preparation, has not negative side-effects and is more cheap. The method of obtaining biocompatible polymers (basically polyethylene) with immobilized 'Piyavit' consist of three stages: 1. The modification of polymer surface by the radiation-induced graft polymerization of acrylic acid to obtain grafted chains polyacrylic acid (PAA) with controlled number and length. 2. The treatment of radiation grafted PAA by thionyl chloride that lead to conversion carboxyl groups of PAA in highly reactive acide chloride groups. 3. The covalent immobilization BAS of 'Piyavit' by acylation amino- and hydroxy-groups (functional groups in BAS) by acide chloride of PAA grafted on the polymere. (author)

  14. Effect of plasma surface modification on the biocompatibility of UHMWPE

    Energy Technology Data Exchange (ETDEWEB)

    Kaklamani, G; Chen, J; Dong, H; Stamboulis, A [School of Metallurgy and Materials, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Mehrban, N; Bowen, J; Grover, L, E-mail: a.stamboulis@bham.ac.u [School of Chemical Engineering, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2010-10-01

    In this paper active screen plasma nitriding (ASPN) is used to chemically modify the surface of UHMWPE. This is an unexplored and new area of research. ASPN allows the homogeneous treatment of any shape or surface at low temperature; therefore, it was thought that ASPN would be an effective technique to modify organic polymer surfaces. ASPN experiments were carried out at 120 {sup 0}C using a dc plasma nitriding unit with a 25% N{sub 2} and 75% H{sub 2} atmosphere at 2.5 mbar of pressure. UHMWPE samples treated for different time periods were characterized by nanoindentation, FTIR, XPS, interferometry and SEM. A 3T3 fibroblast cell line was used for in vitro cell culture experiments. Nanoindentation of UHMWPE showed that hardness and elastic modulus increased with ASPN treatment compared to the untreated material. FTIR spectra did not show significant differences between the untreated and treated samples; however, some changes were observed at 30 min of treatment in the range of 1500-1700 cm{sup -1} associated mainly with the presence of N-H groups. XPS studies showed that nitrogen was present on the surface and its amount increased with treatment time. Interferometry showed that no significant changes were observed on the surfaces after the treatment. Finally, cell culture experiments and SEM showed that fibroblasts attached and proliferated to a greater extent on the plasma-treated surfaces leading to the conclusion that ASPN surface treatment can potentially significantly improve the biocompatibility behaviour of polymeric materials.

  15. Effect of plasma surface modification on the biocompatibility of UHMWPE.

    Science.gov (United States)

    Kaklamani, G; Mehrban, N; Chen, J; Bowen, J; Dong, H; Grover, L; Stamboulis, A

    2010-10-01

    In this paper active screen plasma nitriding (ASPN) is used to chemically modify the surface of UHMWPE. This is an unexplored and new area of research. ASPN allows the homogeneous treatment of any shape or surface at low temperature; therefore, it was thought that ASPN would be an effective technique to modify organic polymer surfaces. ASPN experiments were carried out at 120 °C using a dc plasma nitriding unit with a 25% N(2) and 75% H(2) atmosphere at 2.5 mbar of pressure. UHMWPE samples treated for different time periods were characterized by nanoindentation, FTIR, XPS, interferometry and SEM. A 3T3 fibroblast cell line was used for in vitro cell culture experiments. Nanoindentation of UHMWPE showed that hardness and elastic modulus increased with ASPN treatment compared to the untreated material. FTIR spectra did not show significant differences between the untreated and treated samples; however, some changes were observed at 30 min of treatment in the range of 1500-1700 cm(-1) associated mainly with the presence of N-H groups. XPS studies showed that nitrogen was present on the surface and its amount increased with treatment time. Interferometry showed that no significant changes were observed on the surfaces after the treatment. Finally, cell culture experiments and SEM showed that fibroblasts attached and proliferated to a greater extent on the plasma-treated surfaces leading to the conclusion that ASPN surface treatment can potentially significantly improve the biocompatibility behaviour of polymeric materials. PMID:20876959

  16. Effect of plasma surface modification on the biocompatibility of UHMWPE

    International Nuclear Information System (INIS)

    In this paper active screen plasma nitriding (ASPN) is used to chemically modify the surface of UHMWPE. This is an unexplored and new area of research. ASPN allows the homogeneous treatment of any shape or surface at low temperature; therefore, it was thought that ASPN would be an effective technique to modify organic polymer surfaces. ASPN experiments were carried out at 120 0C using a dc plasma nitriding unit with a 25% N2 and 75% H2 atmosphere at 2.5 mbar of pressure. UHMWPE samples treated for different time periods were characterized by nanoindentation, FTIR, XPS, interferometry and SEM. A 3T3 fibroblast cell line was used for in vitro cell culture experiments. Nanoindentation of UHMWPE showed that hardness and elastic modulus increased with ASPN treatment compared to the untreated material. FTIR spectra did not show significant differences between the untreated and treated samples; however, some changes were observed at 30 min of treatment in the range of 1500-1700 cm-1 associated mainly with the presence of N-H groups. XPS studies showed that nitrogen was present on the surface and its amount increased with treatment time. Interferometry showed that no significant changes were observed on the surfaces after the treatment. Finally, cell culture experiments and SEM showed that fibroblasts attached and proliferated to a greater extent on the plasma-treated surfaces leading to the conclusion that ASPN surface treatment can potentially significantly improve the biocompatibility behaviour of polymeric materials.

  17. Development of novel polymeric materials for gene therapy and pH-sensitive drug delivery: Modeling, synthesis, characterization, and analysis

    Science.gov (United States)

    Anderson, Brian Curtis

    The aim of this work was to obtain a fundamental understanding of drug release mechanisms from polymers that undergo thermoreversible gelation and to synthesize new polymers based on these that exhibit both pH and temperature sensitivity. Novel block and random copolymers with cationic character have been developed for drug delivery and gene therapy applications. The development of these materials began with a study of the mechanism of drug release from poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) block copolymers. This study revealed the release rates of drugs from water-soluble hydrogels composed of the PEO-PPO-PEO block copolymer PluronicRTM F127 was dictated almost solely by the rate of interfacial dissolution at the water/gel interface. A setup was designed to measure drug release from such soluble systems in order to avoid confounding hydrodynamic effects as a result of shear on the delicate polymer/gel interface. This study was followed by a complementary analysis of the effect ionic salts play in the phase transitions and drug release profiles in aqueous F127 solutions. In an attempt to incorporate pH sensitivity into such drug release systems, several block copolymers of poly(N,N-diethylaminoethyl methacrylate) (PDEAEM), PEO and PPO were synthesized via anionic polymerization. Diblock materials (PEO-b-PDEAEM), either with or without a carboxylic acid endcap, were synthesized and characterized. Tablet dissolution experiments demonstrated pH-sensitivity in their drug release profiles relative to PEO tablets. Pentablock materials (PDEAEM-b-PEO-b-PPO- b-PEO-b-PDEAEM) were synthesized that maintain the thermoreversible gelation and micellization properties of F127 while introducing pH-dependent release from aqueous gels of the copolymer. This is the first example of non-crosslinked materials that exhibit both pH- and temperature-sensitive behavior. Using a similar synthesis route, random copolymers of PDEAEM and poly(poly(ethylene glycol) methyl

  18. Nonlinear optical properties of organic and polymeric thin film materials of potential for microgravity processing studies

    Energy Technology Data Exchange (ETDEWEB)

    Abdeldayem, H.; Paley, M.S. [Universities Space Research Association, Huntsville, AL (United States); Frazier, D.O.; Penn, B.; Witherow, W.K.; Bank, C.; Shields, A.; Hicks, R. [NASA-Marshall Space Flight Center, Huntsville, AL (United States). Space Science Lab.; Ashley, P.R. [Army Missile Command, Redstone Arsenal, AL (United States). Research, Development and Engineering Center

    1996-12-31

    In this paper, the authors will take a closer look at the state of the art of polydiacetylene, and metal-free phthalocyanine films, in view of the microgravity impact on their optical properties, there nonlinear optical properties and their potential advantages for integrated optics. Thin films of these materials processed in microgravity environment show enhanced optical quality and better molecular alignment than those processed in unit gravity. Polydiacetylene films are produced by UV irradiation of monomer solution through an optical window. This novel technique of forming polydiacetylene thin films has been modified for constructing sophisticated micro-structure integrated optical patterns using a pre-programmed UV-laser beam. Wave guiding through these thin films by the prism coupler technique has been demonstrated. The third order nonlinear parameters of these films have been evaluated. Metal-free phthalocyanine films of good optical quality are processed in the authors` laboratories by vapor deposition technique. Initial studies on these films indicate that they have excellent chemical, laser, and environmental stability. They have large nonlinear optical parameters and show intrinsic optical bistability.

  19. Accumulation of air in polymeric materials investigated by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yip, W. L.; Hermann, J. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. De Luminy, Marseille 13288 (France); Mothe, E. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. De Luminy, Marseille 13288 (France); Bertin Technology, 155 Rue Louis Armand, Aix-en-Provence 13290 (France); Beldjilali, S. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. De Luminy, Marseille 13288 (France); LPPMCA, Universite des Sciences et de la Technologie d' Oran, BP 1505 El Mnaouer, Oran (Algeria)

    2012-03-15

    We report on spectroscopic analyses of plasmas produced by laser irradiation of nitrogen-free and nitrogen-containing polymer materials. Ultraviolet laser pulses of 5 ns duration and 4 mJ energy were focused onto the samples with a fluence of about 20 Jcm{sup -2}. The plasma emission was analyzed with an Echelle spectrometer equipped with a gated detector. Comparing the spectra recorded during ablation in air and argon, it is shown that the spectral line emission of atomic nitrogen originates from the excitation of the ambient air, whereas the CN molecular bands are essentially emitted from the ablation plume. Furthermore, the measurements demonstrate an additional contribution of nitrogen emission from the air molecules accumulated in the polymer. Storage under vacuum over a duration of the order of one day leads to the release of the absorbed air. As a consequence of the air absorption, the measurement of elemental composition of polymers via laser-induced breakdown spectroscopy is particularly difficult. Here, we quantify the atmospheric contribution to the plume emission during polymer analysis.

  20. Accumulation of air in polymeric materials investigated by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Yip, W. L.; Mothe, E.; Beldjilali, S.; Hermann, J.

    2012-03-01

    We report on spectroscopic analyses of plasmas produced by laser irradiation of nitrogen-free and nitrogen-containing polymer materials. Ultraviolet laser pulses of 5 ns duration and 4 mJ energy were focused onto the samples with a fluence of about 20 Jcm-2. The plasma emission was analyzed with an Echelle spectrometer equipped with a gated detector. Comparing the spectra recorded during ablation in air and argon, it is shown that the spectral line emission of atomic nitrogen originates from the excitation of the ambient air, whereas the CN molecular bands are essentially emitted from the ablation plume. Furthermore, the measurements demonstrate an additional contribution of nitrogen emission from the air molecules accumulated in the polymer. Storage under vacuum over a duration of the order of one day leads to the release of the absorbed air. As a consequence of the air absorption, the measurement of elemental composition of polymers via laser-induced breakdown spectroscopy is particularly difficult. Here, we quantify the atmospheric contribution to the plume emission during polymer analysis.

  1. Impedance Analysis of Heat Treated Polyethylene Oxide Polymeric Material for a Neural Storage Application

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Iskandarani

    2009-01-01

    Full Text Available Problem statement: From the early days of, researchers have developed electronic models of neurons designed to emulate neural behavior with electrical signals that mimic in some ways the measured potentials of biological neurons. Researchers interested in fabricating artificial neurons have long sought a simple and techniques to produce devices that efficiently store synaptic weights, which is behind holding a particular state in relation to conductance parameters. As Engineers become closer to realizing accurate hardware models of neurons, the need for a simple analog memory device grows correspondingly. To determine the storage characteristics of polyethylene oxide based polymer as the base material for high charge storage analogue neural switch. Approach: Various devices prepared under controlled conditions. Each device tested for its impedance characteristics as a function of both frequency and temperature. Mathematical model developed to account for the obtained characteristics. Results: The heat treated devices showed stability, repeatability and ability to store enough charge for long time periods. Impedance analysis proved a similar response to the actual neural switches. Conclusion: The symmetrical behavior for such devices opened a wide application area for the manufacturing of low and high frequency analogue devices for intelligent system applications.

  2. Comparação de métodos para testar a citotoxicidade "in vitro" de materiais biocompatíveis Comparison of methods to test an "in vitro" test of cytotoxicity of biocompatible hospital materials

    Directory of Open Access Journals (Sweden)

    Aurea Silveira Cruz

    1998-04-01

    Full Text Available OBJETIVO: Comparar a sensibilidade do método de difusão em ágar e do método de extração utilizando as linhagens celulares RC-IAL (células fibroblásticas de rim de coelho e HeLa (células epiteliais de carcinoma do colo do útero humano, na avaliação da citotoxicidade "in vitro" de materiais de uso médico-hospitalar. MATERIAL E MÉTODO: Foram testadas 50 amostras escolhidas por sorteio, entre as já conhecidamente positivas e negativas e identificadas como: algodão, espuma, borracha, látex, celulose e acrílico. Além, das amostras citadas foram testadas experimentalmente várias concentrações de SDS (duodecil sulfato de sódio nas culturas celulares RC-IAL e HeLa. RESULTADOS: Das 50 amostras testadas , 44 (88% foram positivas para os dois métodos. Mas quando comparado o SDS nos dois métodos foram observados resultados positivos nas concentrações de 0,5 a 0,05 µg/ml no método de difusão em ágar e no método de extração somente foi observado efeito citotóxico até a concentração de 0,25 µg/ml. CONCLUSÃO: Os resultados encontrados são similares aos observados por outros autores que testaram materiais como, por exemplo, ligas metálicas. Quando foi usado o SDS observou-se, nas duas linhagens celulares, diferenças favoráveis ao método de difusão em ágar em duas concentrações, isto é, a sensibilidade deste método foi significantemente maior, por inspecção, em relação ao método de extração, além de se constituir em método mais simples de ser realizado.OBJECTIVE: A comparison of the sensitivity of the agar diffusion method with that of extraction using cell-lines RC-IAL (fibroblastic of rabbit kidney and HeLa (epithelial carcionoma cells from the cervix uteri of the humam uterus, in the in vitro evaluation of materials of medical and hospital. MATERIAL AND METHODS: Fifteen samples chosen at random, from among the already known positives and negatives in our stock, were tested and identified as cotton

  3. Broad spectrum antibacterial and antifungal polymeric paint materials: synthesis, structure-activity relationship, and membrane-active mode of action.

    Science.gov (United States)

    Hoque, Jiaul; Akkapeddi, Padma; Yadav, Vikas; Manjunath, Goutham B; Uppu, Divakara S S M; Konai, Mohini M; Yarlagadda, Venkateswarlu; Sanyal, Kaustuv; Haldar, Jayanta

    2015-01-28

    Microbial attachment and subsequent colonization onto surfaces lead to the spread of deadly community-acquired and hospital-acquired (nosocomial) infections. Noncovalent immobilization of water insoluble and organo-soluble cationic polymers onto a surface is a facile approach to prevent microbial contamination. In the present study, we described the synthesis of water insoluble and organo-soluble polymeric materials and demonstrated their structure-activity relationship against various human pathogenic bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and beta lactam-resistant Klebsiella pneumoniae as well as pathogenic fungi such as Candida spp. and Cryptococcus spp. The polymer coated surfaces completely inactivated both bacteria and fungi upon contact (5 log reduction with respect to control). Linear polymers were more active and found to have a higher killing rate than the branched polymers. The polymer coated surfaces also exhibited significant activity in various complex mammalian fluids such as serum, plasma, and blood and showed negligible hemolysis at an amount much higher than minimum inhibitory amounts (MIAs). These polymers were found to have excellent compatibility with other medically relevant polymers (polylactic acid, PLA) and commercial paint. The cationic hydrophobic polymer coatings disrupted the lipid membrane of both bacteria and fungi and thus showed a membrane-active mode of action. Further, bacteria did not develop resistance against these membrane-active polymers in sharp contrast to conventional antibiotics and lipopeptides, thus the polymers hold great promise to be used as coating materials for developing permanent antimicrobial paint. PMID:25541751

  4. Subcritical CO2 sintering of microspheres of different polymeric materials to fabricate scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    The aim of this study was to use CO2 at sub-critical pressures as a tool to sinter 3D, macroporous, microsphere-based scaffolds for bone and cartilage tissue engineering. Porous scaffolds composed of ∼ 200 μm microspheres of either poly(lactic-co-glycolic acid) (PLGA) or polycaprolactone (PCL) were prepared using dense phase CO2 sintering, which were seeded with rat bone marrow mesenchymal stromal cells (rBMSCs), and exposed to either osteogenic (PLGA, PCL) or chondrogenic (PLGA) conditions for 6 weeks. Under osteogenic conditions, the PLGA constructs produced over an order of magnitude more calcium than the PCL constructs, whereas the PCL constructs had far superior mechanical and structural integrity (125 times stiffer than PLGA constructs) at week 6, along with twice the cell content of the PLGA constructs. Chondrogenic cell performance was limited in PLGA constructs, perhaps as a result of the polymer degradation rate being too high. The current study represents the first long-term culture of CO2-sintered microsphere-based scaffolds, and has established important thermodynamic differences in sintering between the selected formulations of PLGA and PCL, with the former requiring adjustment of pressure only, and the latter requiring the adjustment of both pressure and temperature. Based on more straightforward sintering conditions and more favorable cell performance, PLGA may be the material of choice for microspheres in a CO2 sintering application, although a different PLGA formulation with the encapsulation of growth factors, extracellular matrix-derived nanoparticles, and/or buffers in the microspheres may be advantageous for achieving a more superior cell performance than observed here. - Highlights: • The first long-term culture of CO2-sintered microsphere-based scaffolds. • Established important thermodynamic differences between sintering PLGA and PCL. • PCL sintering with CO2 required manipulation of both temperature and pressure. • PLGA may be

  5. RAFT Polymerization of N-[3-(Trimethoxysilyl)-propyl]acrylamide and Its Versatile Use in Silica Hybrid Materials.

    Science.gov (United States)

    Maçon, Anthony L B; Greasley, Sarah L; Becer, C Remzi; Jones, Julian R

    2015-12-01

    Reversible addition-fragmentation chain transfer (RAFT) polymerization and characterization of an alkoxysilane acrylamide monomer using a trithiocarbonate chain transfer agent are described. Poly(N-[3-(trimethoxysilyl)propyl]acrylamide) (PTMSPAA) homopolymers are obtained with good control over the polymerization. A linear increase in the molecular weight is observed whereas the polydispersity values do not exceed 1.2 regardless of the monomer conversion. Moreover, PTMSPAA is used as a macro-RAFT agent to polymerize N-isopropylacrylamide (NIPAM). By varying the degree of polymerization of NIPAM within the block copolymer, different sizes of thermoresponsive particles are obtained. These particles are stabilized by the condensation of the alkoxysilane moieties of the polymers. Furthermore, a co-network of silica and PTMSPAA is prepared using the sol-gel process. After drying, transparent mesoporous hybrids are obtained with a surface area of up to 400 m(2) g(-1). PMID:26288010

  6. Biocompatible Metal-Oxide Nanoparticles: Nanotechnology Improvement of Conventional Prosthetic Acrylic Resins

    International Nuclear Information System (INIS)

    Nowadays, most products for dental restoration are produced from acrylic resins based on heat-cured Poly(Methyl Methacrylate) (PMMA). The addition of metal nanoparticles to organic materials is known to increase the surface hydrophobicity and to reduce adherence to biomolecules. This paper describes the use of nano structured materials, TiO2 and Fe2O3, for simultaneously coloring and/or improving the antimicrobial properties of PMMA resins. Nanoparticles of metal oxides were included during suspension polymerization to produce hybrid metal oxides-alginate-containing PMMA. Metal oxide nanoparticles were characterized by dynamic light scattering, and X-ray diffraction. Physicochemical characterization of synthesized resins was assessed by a combination of spectroscopy, scanning electron microscopy, viscometry, porosity, and mechanical tests. Adherence of Candida albicans cells and cellular compatibility assays were performed to explore biocompatibility and microbial adhesion of standard and novel materials. Our results show that introduction of biocompatible metal nanoparticles is a suitable means for the improvement of conventional acrylic dental resins.

  7. Solubility of dense CO2 in two biocompatible acrylate copolymers

    Directory of Open Access Journals (Sweden)

    A. R. C. Duarte

    2006-06-01

    Full Text Available Biocompatible polymers and copolymers are frequently being used as part of controlled delivery systems. These systems can be prepared using a "clean and environment friendly" technology like supercritical fluids. One great advantage of this process is that compressed carbon dioxide has excellent plasticizing properties and can swell most biocompatible polymeric matrixes, thus promoting drug impregnation processes. Mass sorption of two acrylate biocompatible copolymers contact with supercritical carbon dioxide is reported. Equilibrium solubility of dense carbon dioxide in poly(methylmethacrylate-co-ethylhexylacrylate and poly(methylmethacrylate-co-ethylhexylacrylate-co-ethyleneglycoldimethacrylate was studied by a static method at 10.0 MPa and 313 K. The reticulated copolymer had Fickean behavior and its diffusion coefficient was calculated, under operating conditions.

  8. 生物珊瑚人工骨支架材料生物相容性检测%Biocompatibility test of biological coral artificial bone as scaffold materials

    Institute of Scientific and Technical Information of China (English)

    黄涛; 孟志斌; 金大地; 付昆; 刘建航; 宋策; 贾丙申

    2012-01-01

    目的 评价生物珊瑚人工骨( BCAB)材料作为骨组织工程支架材料与小鼠胚胎干细胞(MESCs)构建组织工程骨的有效性及材料生物相容性.方法 设MESCs与BCAB支架材料混合黏附培养为实验组,单纯MESCs培养为对照组,分别于第2、4、6、8天进行MTT法检测细胞增殖活性,特异性胚胎抗原-1检测细胞对材料的黏附性.于第8日对接种细胞材料片行成骨诱导,诱导培养10d后行茜素红染色及电镜扫描检测成骨诱导及体外组织工程骨构建情况.取12只大鼠,脊柱左侧皮下植入空白BCAB支架片状材料,右侧植入黏附细胞BCAB片状材料,随机分4、8、12周3组行影像学检查,并取双侧标本行病理切片观察局部炎症反应,四环素标记下荧光显微镜观察成骨情况.第12周组取心、肝、肾病理切片及评估心、肝、肾毒性反应.结果 MTT法检测细胞增殖活性结果显示,在培养2d和4d时实验组与对照组间MTT值差异无统计学意义(P>0.05),在6d及8d时实验组MTT值明显高于对照组,差异具有统计学意义(P<0.05).特异性胚胎抗原-1检测证实MESCs对BCAB支架材料具有良好的黏附性,在其三维微孔隙内能较快增殖.茜素红染色及电镜扫描检测证实黏附细胞材料成骨诱导有效,体外组织工程骨构建成功.材料植入局部组织炎症反应轻,空白支架材料于第8周开始降解,12周达初步降解,无异位成骨;黏附细胞支架材料则有明显异位成骨现象,且较对侧空白支架材料降解时效延长.第12周组实验动物心、肝、肾标本病理切片未见异常损害.结论 BCAB支架材料具有良好的生物相容性,其降解周期与新骨重建周期大致相当,是一种良好的骨组织工程支架材料.%[Objective] To test the biocompatibility of biological coral artificial bone (BCAB) and the efrect of tissue engineered bone construction using BCAB scaffolds with mouse embryonic stem cells (MESCs

  9. Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

    International Nuclear Information System (INIS)

    A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

  10. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-01-22

    The present application offers a solution to the current problems associated with recovery and recycling of precious metals from scrap material, discard articles, and other items comprising one or more precious metals. The solution is premised on a microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  11. Evaluation of solid polymeric organic materials for use in bioreactive sediment capping to stimulate the degradation of chlorinated aliphatic hydrocarbons.

    Science.gov (United States)

    Atashgahi, Siavash; Maphosa, Farai; De Vrieze, Jo; Haest, Pieter Jan; Boon, Nico; Smidt, Hauke; Springael, Dirk; Dejonghe, Winnie

    2014-03-01

    In situ bioreactive capping is a promising technology for mitigation of surface water contamination by discharging polluted groundwater. Organohalide respiration (OHR) of chlorinated ethenes in bioreactive caps can be stimulated through incorporation of solid polymeric organic materials (SPOMs) that provide a sustainable electron source for organohalide respiring bacteria. In this study, wood chips, hay, straw, tree bark and shrimp waste, were assessed for their long term applicability as an electron donor for OHR of cis-dichloroethene (cDCE) and vinyl chloride (VC) in sediment microcosms. The initial release of fermentation products, such as acetate, propionate and butyrate led to the onset of extensive methane production especially in microcosms amended with shrimp waste, straw and hay, while no considerable stimulation of VC dechlorination was obtained in any of the SPOM amended microcosms. However, in the longer term, short chain fatty acids accumulation decreased as well as methanogenesis, whereas high dechlorination rates of VC and cDCE were established with concomitant increase of Dehalococcoides mccartyi and vcrA and bvcA gene numbers both in the sediment and on the SPOMs. A numeric simulation indicated that a capping layer of 40 cm with hay, straw, tree bark or shrimp waste is suffice to reduce the groundwater VC concentration below the threshold level of 5 μg/l before discharging into the Zenne River, Belgium. Of all SPOMs, the persistent colonization of tree bark by D. mccartyi combined with the lowest stimulation of methanogenesis singled out tree bark as a long-term electron donor for OHR of cDCE/VC in bioreactive caps. PMID:23955471

  12. Metallized polymeric foam material

    Science.gov (United States)

    Birnbaum, B. A.; Bilow, N.

    1974-01-01

    Open-celled polyurethane foams can be coated uniformly with thin film of metal by vapor deposition of aluminum or by sensitization of foam followed by electroless deposition of nickel or copper. Foam can be further processed to increase thickness of metal overcoat to impart rigidity or to provide inert surface with only modest increase in weight.

  13. Semiconducting polymeric materials

    NARCIS (Netherlands)

    de Boer, Bert; Facchetti, Antonio

    2008-01-01

    (Semi)conducting polymers with a pi-conjugated (hetero)aromatic backbone are capable of transporting charge and interact efficiently with light enabling their utilization in a variety of opto-electronic devices. In this report and in the additional papers of this special issue, several classes of pi

  14. Substrate-anchored and degradation-sensitive anti-inflammatory coatings for implant materials

    OpenAIRE

    Duo Wu; Xingyu Chen; Tianchan Chen; Chunmei Ding; Wei Wu; Jianshu Li

    2015-01-01

    Implant materials need to be highly biocompatible to avoid inflammation in clinical practice. Although biodegradable polymeric implants can eliminate the need for a second surgical intervention to remove the implant materials, they may produce acidic degradation products in vivo and cause non-bacterial inflammation. Here we show the strategy of “substrate-anchored and degradation-sensitive coatings” for biodegradable implants. Using poly(lactic acid)/hydroxyapatite as an implant material mode...

  15. 镍铬合金材料与口腔软组织的生物相容性%Biocompatibility of Ni-Cr alloy materials and oral soft tissue

    Institute of Scientific and Technical Information of China (English)

    金芮竹; 赵驰

    2012-01-01

    BACKGROUND: Ni-Cr alloy ceramic materials are accepted by the majority of patients due to the low prices, and more than 50% of patients choose the Ni-Cr alloy porcelain teeth. Due to the materials persisting in the electrolyte environment, precipitation of nickel ions can cause allergy in some patients. How to improve the biological safety of Ni-Cr alloy materials arises more attention. OBJECTIVE: Using CNKI database literature search and the depth of analysis capabilities, to explore the literature data trends in the study of biocompatibility of Ni-Cr alloy materials and oral soft tissue. DESIGN: Bibliometric data analysis.DATA RETRIEVAL: A search of related literature of biocompatibility of Ni-Cr alloy materials and oral soft tissue was performed in CNKI database using the key words of "Ni-Cr alloy", "biomaterials" and "biocompatibility", during 2002-01 to 2011-12. Own database analysis capabilities and Excel charting functions were used to retrieve literature analysis; through the form of text and charts, the data were analyzed to describe the distribution characteristics.SELECTION CRITERIA: Inclusive criteria: ?Basic research papers related to Ni-Cr alloy materials. ?Papers related to the clinical application of Ni-Cr alloy materials. ?Research papers related to biocompatibility of Ni-Cr alloy materials. Exclusive criteria: ?Literature has nothing to do with the purpose of this review. ?Duplication of research literature. ?Journal's own information. ?Unpublished papers. ?The article need telephone follow up to analyze and manual searches. ?Year book. MAIN OUTCOME MEASUREMENTS: In CNKI database, academic journal articles published year, literature number, subject category, research institutions, source journals, literature citations, literature download frequency, associated literature, distribution of the author, distribution of the fund and major keywords were analyzed, the Ph.D. Thesis, outstanding master's degree papers, conference papers, patented

  16. Preparation and Characterization of Hybrid Organic-Inorganic Composite Material: Polymerization of m-Aminobenzoic Acid-Intercalated Into Zn/Al-Layered Double Hydroxides

    Directory of Open Access Journals (Sweden)

    Rasheed M.A.Q. Jamhour

    2005-01-01

    Full Text Available Layered double hydroxides of aluminum and zinc (Zn/Al-LDH’s were synthesized directly by hydrolysis at room temperature as reported elsewhere. After characterization, the material was reacted with m-aminobenzoat anion (m-NH2C6H4COO- which undergoes polymerization in the interlayer space; resulting in the formation of a matrix with polymeric organic macromolecule. The resulting material along with the host LDH’s compound of Zn/Al-Cl was characterized by X-Ray Powder Diffraction (PXRD, Thermal Analysis (TG, Differential Thermal Analysis (DTA, and Fourier Transform Infrared Spectroscopy (FTIR. The study confirms the intercalation of m-aminobenzoat anion. Diffusion of oxygen molecules between the contact region of two anions in the interlayer space and oxidation of the anion lead to the formation of a polymer macromolecule. This intercalation compound result in a gallery height of 15.8 A, indicating that the guest anion stack to form a monolayer with the benzene rings perpendicular to the host layers, giving a suitable orientation for polymerization.

  17. Biocompatibility and Bioactivity of Magnesium Matrix Hydroxyapatite Material%镁合金基HA材料生物相容性及生物活性的研究

    Institute of Scientific and Technical Information of China (English)

    林国湘; 薛顺; 李林升; 葛丽婧

    2015-01-01

    Magnesium matrix hydroxyapatite biological composite material was prepared by electrophoretic deposition method, and the biocompatibility and biological activity of this material was discussed. Animal experiment and SBF immersion experiment were selected separately to test the biocompatibility and bioactivity. The SD rats were divided into con-trast group and implant group. The implant material surrounding tissue was taken to do Tis-sue biopsy,HE dyed and organizational analysis after a certain amount of time in the SD body. Under homeothermic condition,the biological composite material was soaked in SBF solution. After four weeks,the bioactivity of the biological composite material was evaluated by testing the growth ability of hydroxyapatite on composite material. The experiment re-sults showed that the implant material surrounding appeared tissue hyperplasia,connective tissue and new blood vessels,but no obvious tissue inflammation,no infiltrating inflammato-ry cells such as multinuclear giant cells and neutrophils cells. After the biological compos-ite material was soaked in SBF solution,a layer Bone-Like Apatite was found on its sur-face. The results showed that Magnesium matrix hydroxyapatite biological composite materi-al have no cytotoxicity,induction bone formation,good biocompatibility and bioactivity.%采用电泳沉积法制备了镁合金基羟基磷灰石表面涂层生物复合材料。利用动物体内埋植实验和SBF浸泡实验分别对复合材料生物相容性及生物活性进行研究。将SD大鼠分为对照组和植入组,植入一定的时间后,取植入物周围组织进行切片、HE染色和组织分析;将复合材料恒温浸泡于SBF溶液四周后取出,通过检测复合材料表面生长磷灰石的能力作为评价该材料的生物活性。实验结果是植入物周围出现组织增生,有结缔组织及新生血管的形成,未见明显的组织炎症反应,无多核的巨细胞、淋巴细胞和中性

  18. A multi-sphere indentation method to determine Young's modulus of soft polymeric materials based on the Johnson–Kendall–Roberts contact model

    International Nuclear Information System (INIS)

    Tissue cells can sense mechanical properties of their surroundings, which, in vitro, generally refer to substrates coated with proteins. The elastic moduli of soft polymers used as substrates have been proved to affect many cellular processes, such as migration, development, and even differentiation. In this note, we present a cost-effective experimental design by using multi-sphere indentations to find the relation between indentation depth and sphere radius, and then apply the Johnson–Kendall–Roberts (JKR) contact theory with consideration of adhesive work to fit the experimental results so as to assess the value of Young's modulus. Two compliant polymeric materials, polyacrylamide gels and polydimethylsiloxane elastomers, are tested with this method. The results are in good agreement with those reported by previous experiments. Comparisons between JKR and traditional Hertz fittings highlight the demand for taking adhesive forces into account to measure Young's modulus of soft sticky polymeric substrates in cell–substrate interaction studies. (technical design note)

  19. FABRICATION AND BIOCOMPATIBILITY OF CELL OUTER MEMBRANE MIMETIC SURFACES

    Institute of Scientific and Technical Information of China (English)

    Ming-ming Zong; Yong-kuan Gong

    2011-01-01

    The surface design used for improving biocompatibility is one of the most important issues for the fabrication of medical devices. For mimicking the ideal surface structure of cell outer membrane, a large number of polymers bearing phosphorylcholine (PC) groups have been employed to modify the surfaces of biomaterials and medical devices. It has been demonstrated that the biocompatibility of the modified materials whose surface is required to interact with a living organism has been obviously improved by introducing PC groups. In this review, the fabrication strategies of cell outer membrane mimetic surfaces and their resulted biocompatibilities were summarized.

  20. Decreased material-activation of the complement system using low-energy plasma polymerized poly(vinyl pyrrolidone) coatings

    DEFF Research Database (Denmark)

    Andersen, Thomas E; Palarasah, Yaseelan; Skjødt, Mikkel-Ole;

    2011-01-01

    In the current study we investigate the activation of blood complement on medical device silicone rubber and present a plasma polymerized vinyl pyrrolidone (ppVP) coating which strongly decreases surface-activation of the blood complement system. We show that uncoated silicone and polystyrene are...

  1. Polymeric and Ceramic Nanoparticles in Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Aura-Ileana Moreno-Vega

    2012-01-01

    Full Text Available Materials in the nanometer size range may possess unique and beneficial properties, which are very useful for different medical applications including stomatology, pharmacy, and implantology tissue engineering. The application of nanotechnology to medicine, known as nanomedicine, concerns the use of precisely engineered materials at this length scale to develop novel therapeutic and diagnostic modalities. Nanomaterials have unique physicochemical properties, such as small size, large surface area to mass ratio, and high reactivity, which are different from bulk materials of the same composition. Polymeric and ceramic nanoparticles have been extensively studied as particulate carriers in the pharmaceutical and medical fields, because they show promise as drug delivery systems as a result of their controlled- and sustained-release properties, subcellular size, and biocompatibility with tissue and cells. These properties can be used to overcome some of the limitations found in traditional therapeutic and diagnostic agents. Nanotechnology is showing promising developments in many areas and may benefit our health and welfare. However, a wide range of ethical issues has been raised by this innovative science. Many authorities believe that these advancements could lead to irreversible disasters if not limited by ethical guidelines.

  2. Polymeric biomaterials structure and function, v.1

    CERN Document Server

    Dumitriu, Severian

    2013-01-01

    Biomaterials have had a major impact on the practice of contemporary medicine and patient care. Growing into a major interdisciplinary effort involving chemists, biologists, engineers, and physicians, biomaterials development has enabled the creation of high-quality devices, implants, and drug carriers with greater biocompatibility and biofunctionality. The fast-paced research and increasing interest in finding new and improved biocompatible or biodegradable polymers has provided a wealth of new information, transforming this edition of Polymeric Biomaterials into a two-volume set. This volume

  3. Elektroaktive polymerer

    DEFF Research Database (Denmark)

    West, K.

    Traditionelt tænker vi på polymerer (plastik) som elektrisk isolerende materialer - det som er udenpå ledningerne. I dag kender vi imidlertid også polymerer med intrinsisk elektrisk ledningsevne, og plast er på vej ind i anvendelser, der tidligereudelukkende var baseret på metaller og uorganiske...... halvledere. Hertil kommer, at en del af de ledende polymerer kan stimuleres til at skifte mellem en ledende og en halvledende tilstand, hvorved de ændret både form og farve. I foredraget gives der enrække eksempler på anvendelse af polymerer som elektriske komponenter - rækkende fra polymer elektronik over...

  4. “Controlled” and “Living” Cationic Polymerizations:Another Way Towards Well Defined Polymer Architectures and Materials

    Institute of Scientific and Technical Information of China (English)

    Jean-Pierre; Vairon; Michel; Moreau; Rudolf; Faust

    2007-01-01

    1 Results No doubt that one of the major breakthroughs in polymer chemistry was the discovery and the progressive implementation of the "living" and "controlled" polymerizations.These now widely used techniques allow not only to control with an extreme precision the molar masses and their distributions but also to synthesise easily a broad variety of architectures from block and graft copolymers,miktoarms stars,to polymer brushes,hyperbranched polymers,dendrimers,etc....They opened an immense domain of ...

  5. Resent Advances in Service Lifetime Prediction of Polymeric Materials%高分子材料服役寿命预测方法最新进展

    Institute of Scientific and Technical Information of China (English)

    祁黎; 王俊

    2014-01-01

    Polymeric materials would degrade gradually or even lose use value in usage due to various environmental factors, causing waste of resources or even hidden danger. In response to the problem of aging, various aging mechanism and service lifetime prediction methods have been proposed and various aging indicators, such as macro performances or micro structure or components have been used in aging characterization based on detail study on polymeric materials environmental adaptability. Overview of resent advances in polymeric materials service lifetime prediction methods have been given in this paper in view of aging indictor and characterization.%高分子材料在使用过程中,由于受各种环境因素作用,会逐步出现性能下降,甚至丧失使用价值的老化现象,不仅造成资源浪费,更形成安全隐患。为应对老化问题,研究者以各种宏观性能或微观结构、组份的变化来表征老化过程,针对高分子材料的环境适应性开展了大量研究工作,并在此基础上提出了不同的老化机理和服役寿命预测方法。从高分子材料老化过程表征的视角,综述了近年来高分子材料服役寿命预测方法的最新进展。

  6. Cellular biocompatibility of various electrospun nPCL/HA scaffold materials%不同配比纳米羟基磷灰石/聚己内酯复合材料细胞相容性的研究

    Institute of Scientific and Technical Information of China (English)

    李家锋; 万美蓉; 管海虹; 贺文鹏; 张红闯; 张扬; 陈丽娟

    2011-01-01

    目的:观察不同配比nPCL/HA电纺纤维取向薄膜材料的细胞相容性.方法:将人骨髓间充质干细胞(hBMSCs)体外诱导培养为成骨细胞;并经传代培养第5代的人骨髓间充质干细胞,以2×105cm2的密度与不同配比nPCL/HA电纺纤维取向薄膜支架在培养板内共培养,同时以nPCL电纺纤维非取向薄膜材料作为对照,初步观察hBMSCs在不同配比nPCL/HA支架材料上复合培养,对其细胞相容性进行评价.结果:hBMSCs与3种电纺薄膜支架材料均有细胞相容性,细胞能在不同材料表面黏附生长、分化增殖.但是PCL/HA的配比为20∶1电纺纤维取向薄膜材料黏附率(35.3±2.6)%,为3中材料中黏附率最高的一种,材料表面细胞生长良好,体积变大,有伪足生长.结论:PCL/HA的配比为20∶1电纺纤维取向薄膜材料,较适合作为支架材料应用于hBMSCs 为种子细胞的组织工程构建.%Objective To investigate cellular biocompatibility of different nPCL/HA scaffold materials. Methods Electrostatic spinning or electrospinning is an interesting method for producing nonwoven fibers with diameters of submicrometers down to nanometers. Nanofibrous membranes were used in many biomedical applications including drug delivery, wound healing and scaffolding for tissue engineering. Novel bone-scaffolding materials were successfully fabricated by electrospinning from polycaprolactone (PCL) solutions containing nanoparticles of hydroxyapatite (HA). In intro cultured hBMSCs (5th generation) were seeded at the density of 2×105 cell/cm2 onto scaffolds of nPCL/HA and nPCL as control. The cell-material complex was observed in order to evaluate the cellular biocompatibility between cells and materials. Results HBMSCs were shown good adhesion to all 3 types of scaffolds after seeding. The cellular biocompatibility of nPCL/HA (20:1) (35.3±2.6)% was higher than the others. Conclusion Nano-PCL/HA (20:1) was shown significantly higher adhesion rate to h

  7. Study and selection of structured packing material: metallic, polymeric or ceramic to operate a column of absorption polluting gases coming from brick kilns efficiently

    International Nuclear Information System (INIS)

    In this research three structured packing materials were characterized: a metallic, polymeric and ceramic. The study of the physical properties of structured packing materials, and their behavior within the absorption column allowed to suggest a gas-liquid contactor material with higher mechanical and chemical resistance, which is more efficient for the treatment of sour gases from brick kilns. To study the mechanical properties (hardness, tension and elastic modulus) were used procedures of the American Society for Testing Materials, as well as resistance to corrosion. The geometric characteristics, the density, the melting temperature and the weight were tested with procedures of the measuring equipment. The structure was evaluated by X-ray diffraction, morphology was observed by scanning electron microscopy coupled to a sound of dispersive energy of X-ray, to quantify elemental chemical composition. The interaction of gas-liquid contactors materials in presence of CO2, was evaluated in three absorption columns built of Pyrex glass, with a diameter of 0.1016 m, of 1.5 m in height, 0.0081m2 cross-sectional area, packed with every kind of material: metallic, polymeric and ceramic, processing a gas flow of 20m3 / h at 9% CO2, in air and a liquid flow to 30% of Mea 5 L/min. The results of the properties studied were by the metallic material: more density, higher roughness, the greater tensile strength, greater resistance to corrosion in the presence of an aqueous solution of monoethanolamine (Mea) to 30% by weight, improvement more efficient absorption of CO2, and higher modulus of elasticity. The polymeric material was characterized to have lower hardness, lower roughness, lower density, lower melting temperature, greater resistance to corrosion in the presence of 1 N H2SO4 aqueous solution, and allowed an absorption efficiency of CO2, 2% lower than that presented by the material metallic. The ceramic material found to be the hardest of the three materials studied

  8. Infrared study of biocompatible magnetic nanoparticles

    International Nuclear Information System (INIS)

    Magnetic fluids mainly consist of nano sized iron oxide particles (FesO4) that are suspended in carrier liquid. In recent years, substantial progress has been made in developing technologies in the field of magnetic nanoparticles. Techniques based on using of these biocompatible magnetizable complex systems have found application in numerous biological fields. Generally, the magnetic component of the particle is coated by a biocompatible polymer such as PEG (polyethylene glycol), policyholder's as dextran, starch, have been developed. The coating acts to shield the magnetic particle from the surrounding environment. This review is focused on describing the infrared spectroscopy as method that allows checking starting materials and reactions while work is in progress. FTIR method is correlated with others spectral methods as XRD, TEM. Keywords: Magnetic nanoparticles, infrared spectroscopy, biomedicine

  9. A biocompatible magnetic film: synthesis and characterization

    Science.gov (United States)

    Chatterjee, Jhunu; Haik, Yousef; Chen, Ching Jen

    2004-01-01

    Background Biotechnology applications of magnetic gels include biosensors, targeted drug delivery, artificial muscles and magnetic buckles. These gels are produced by incorporating magnetic materials in the polymer composites. Methods A biocompatible magnetic gel film has been synthesized using polyvinyl alcohol. The magnetic gel was dried to generate a biocompatible magnetic film. Nanosized iron oxide particles (γ-Fe2O3, ~7 nm) have been used to produce the magnetic gel. Results The surface morphology and magnetic properties of the gel films were studied. The iron oxide particles are superparamagnetic and the gel film also showed superparamagnetic behavior. Conclusion Magnetic gel made out of crosslinked magnetic nanoparticles in the polymer network was found to be stable and possess the magnetic properties of the nanoparticles. PMID:14761251

  10. Polymeric microcapsules poduction from sodium alginic acid for cell therapy

    Directory of Open Access Journals (Sweden)

    Ana Carolina Vale Campos Lisboa

    2007-12-01

    Full Text Available Development of polymeric materials has been increasingly emphasized in Biomedicine. Here, we evaluate the use of microcapsules made of Biodritin®, a biocompatible polymer compound which contains sodium alginic acid, a natural polymer extracted from algae, and Cis-Chondroitin sulfate, a glycosaminoglycan from the extracellular matrix. Gelation of this polymer into microcapsules is achieved by dropping the compound into BaCl2 or CaCl2 gelling solutions. A functional microcapsule is dependent on its permeability, mechanical stability, immunoisolation capacity and biocompatibility. The mechanical stability of Biodritin-barium and Biodritin-calcium microcapsules was investigated after rotational stress upon in vitro culture and in vivo implantation. Viability studies of encapsulated cells were also performed to assess other functional parameters of the microcapsules. When subject to rotational stress, Biodritin-barium microcapsules exhibited breaks, whereas the Biodritin-calcium microcapsules did not. Both kinds of Biodritin® microcapsules proved to be mechanically resistant in in vitro and in vivo studies. However, the Biodritin-calcium material was found to be more elastic while the Biodritin-barium microcapsules displayed a more plastic behavior. These properties seem to be determinant for viability of the encapsulated cell’s, since the Biodritin-calcium microcapsules presented more viable cells than the Biodritin-barium microcapsules.

  11. Biocompatibility of Coronary Stents

    Directory of Open Access Journals (Sweden)

    Thamarasee M. Jeewandara

    2014-01-01

    Full Text Available Cardiovascular disease is the dominant cause of mortality in developed countries, with coronary artery disease (CAD a predominant contributor. The development of stents to treat CAD was a significant innovation, facilitating effective percutaneous coronary revascularization. Coronary stents have evolved from bare metal compositions, to incorporate advances in pharmacological therapy in what are now known as drug eluting stents (DES. Deployment of a stent overcomes some limitations of balloon angioplasty alone, but provides an acute stimulus for thrombus formation and promotes neointimal hyperplasia. First generation DES effectively reduced in-stent restenosis, but profoundly delay healing and are susceptible to late stent thrombosis, leading to significant clinical complications in the long term. This review characterizes the development of coronary stents, detailing the incremental improvements, which aim to attenuate the major clinical complications of thrombosis and restenosis. Despite these enhancements, coronary stents remain fundamentally incompatible with the vasculature, an issue which has largely gone unaddressed. We highlight the latest modifications and research directions that promise to more holistically design coronary implants that are truly biocompatible.

  12. Polymeric nanoparticles for targeted drug delivery system for cancer therapy.

    Science.gov (United States)

    Masood, Farha

    2016-03-01

    A targeted delivery system based on the polymeric nanoparticles as a drug carrier represents a marvelous avenue for cancer therapy. The pivotal characteristics of this system include biodegradability, biocompatibility, non-toxicity, prolonged circulation and a wide payload spectrum of a therapeutic agent. Other outstanding features are their distinctive size and shape properties for tissue penetration via an active and passive targeting, specific cellular/subcellular trafficking pathways and facile control of cargo release by sophisticated material engineering. In this review, the current implications of encapsulation of anticancer agents within polyhydroxyalkanoates, poly-(lactic-co-glycolic acid) and cyclodextrin based nanoparticles to precisely target the tumor site, i.e., cell, tissue and organ are highlighted. Furthermore, the promising perspectives in this emerging field are discussed. PMID:26706565

  13. Doped biocompatible layers prepared by laser

    Science.gov (United States)

    Jelínek, M.; Weiserová, M.; Kocourek, T.; Jurek, K.; Strnad, J.

    2010-03-01

    The contribution deals with KrF laser synthesis and study of doped biocompatible materials with focus on diamond-like carbon (DLC) and hydroxyapatite (HA). Overview of materials used for dopation is given. Experimental results of study of HA layers doped with silver are presented. Films properties were characterized using profilometer, SEM, WDX, XRD and optical transmission. Content of silver in layers moved from 0.06 to 13.7 at %. The antibacterial properties of HA, silver and doped HA layers were studied in vivo using Escherichia coli cells.

  14. Tailoring Properties of Biocompatible PEG-DMA Hydrogels with UV Light

    DEFF Research Database (Denmark)

    Bäckström, Sania; Benavente, Juana; Berg, Rolf W.;

    2012-01-01

    Hydrogels are highly water-absorbent hydrophilic polymer networks, which show potential in many biocompatible ap- plications. In previous work, we demonstrated the feasibility of using poly(ethylene glycol) dimethacrylate (PEG-DMA) gels polymerized with a photoinitiator for encapsulation and stab...

  15. Exfoliating biocompatible ferromagnetic Cr-trihalide monolayers.

    Science.gov (United States)

    Liu, Junyi; Sun, Qiang; Kawazoe, Yoshiyuki; Jena, Puru

    2016-03-23

    In addition to spintronics another motivation for exploring ferromagnetic two-dimensional materials is for biomedical applications such as magnetic labeling and hyperthermia treatment of tumors. Unfortunately, the widely studied Mn-containing monolayer is not biocompatible, although it is ferromagnetic. Here using first principles calculations combined with Monte Carlo simulations based on the Ising model, we systematically study a class of 2D ferromagnetic monolayers CrX3 (X = Cl, Br, I). The feasibility of exfoliation from their layered bulk phase is confirmed by the small cleavage energy and high in-plane stiffness. Spin-polarized calculations, combined with self-consistently determined Hubbard U that accounts for strong correlation energy, demonstrate that CrX3 (X = Cl, Br, I) monolayers are ferromagnetic and that Cr is trivalent and carries a magnetic moment of 3 μB; the resulting Cr(3+) ions are biocompatible. The corresponding Curie temperatures for CrCl3, CrBr3 and CrI3 are found to be 66, 86, and 107 K, respectively, which can be increased to 323, 314, and 293 K by hole doping. The biocompatibility and ferromagnetism render these Cr-containing trihalide monolayers unique for applications. PMID:26452203

  16. Utilizing advanced polymerization techniques for simplifying polymer grafting from silica colloidal crystal substrates

    Science.gov (United States)

    Yerneni, Charu K.

    Polyacrylamide has been well established as a biocompatible material when Polyacrylamide gel electrophoresis (PAGE) came into existence in the 1960s. Under aqueous buffer conditions it becomes non-adsorptive to proteins and due to its molecular level pore forming nature could be used in size based biomolecule separations. Since then considerable research has been done to explore the non-adsorptive nature of polyacrylamide on a platform or substrate. Attempts were made to grow polyacrylamide chains from silica as a substrate which can then be used in various protein separation techniques. Based on an ionic polymerization method which was used for gel casting in PAGE, polymers were grown on silica gel. Though considerable thickness could be achieved, polymerization was not just confined to the surface. Therefore a rigid polymer brush layer could not be achieved. Atom transfer radical polymerization (ATRP) method showed the solution to this problem. Polymer brush layers with acceptable thickness could now be achieved for growing polyacrylamide from silica gel. Yet it still suffered from several disadvantages such as the need of an inert atmosphere for polymerization and limited thickness. Many developments have taken place in the past decade which led to improvements in substrate and polymerization methods. This research used non porous sub-micron silica as the substrate and AGET ATRP (Activator generated electron transfer atom transfer radical polymerization) for surface grafting polyacrylamide. Non porous submicron silica has been shown to be a better stationary phase substrate for protein separations than conventional substrates. AGET ATRP enables polymerization to be performed under ambient conditions and in water based solutions which gives thicknesses much higher than conventional ATRP. Data from various analytical techniques showed that within the experimental range the polymerization is linear and has decent control. This means silica nanoparticles coated with

  17. Synthetic cornea: biocompatibility and optics

    Science.gov (United States)

    Parel, Jean-Marie A.; Kaminski, Stefan; Fernandez, Viviana; Alfonso, E.; Lamar, Peggy; Lacombe, Emmanuel; Duchesne, Bernard; Dubovy, Sander; Manns, Fabrice; Rol, Pascal O.

    2002-06-01

    Purpose. Experimentally find a method to provide a safe surgical technique and an inexpensive and long lasting mesoplant for the restoration of vision in patients with bilateral corneal blindness due to ocular surface and stromal diseases. Methods. Identify the least invasive and the safest surgical technique for synthetic cornea implantation. Identify the most compatible biomaterials and the optimal shape a synthetic cornea must have to last a long time when implanted in vivo. Results. Penetrating procedures were deemed too invasive, time consuming, difficult and prone to long term complications. Therefore a non-penetrating delamination technique with central trephination was developed to preserve the integrity of Descemet's membrane and the anterior segment. Even though this approach limits the number of indications, it is acceptable since the majority of patients only have opacities in the stroma. The prosthesis was designed to fit in the removed tissue plane with its skirt fitted under the delaminated stroma. To improve retention, the trephination wall was made conical with the smallest opening on the anterior surface and a hat-shaped mesoplant was made to fit. The skirt was perforated in its perimeter to allow passage of nutrients and tissues ingrowths. To simplify the fabrication procedure, the haptic and optic were made of the same polymer. The intrastromal biocompatibility of several hydrogels was found superior to current clinically used PMMA and PTFE materials. Monobloc mesoplants made of 4 different materials were implanted in rabbits and followed weekly until extrusion occurred. Some remained optically clear allowing for fundus photography. Conclusions. Hydrogel synthetic corneas can be made to survive for periods longer than 1 year. ArF excimer laser photoablation studies are needed to determine the refractive correction potential of these mesoplants. A pilot FDA clinical trial is needed to assess the mesoplant efficacy and very long-term stability.

  18. Biofilm formation, bacterial adhesion and host response on polymeric implants-issues and prevention

    International Nuclear Information System (INIS)

    Several polymeric materials find application in biomedical implants and devices due to their superior physicochemical properties. The main requirement for these polymers is that they should be biocompatible, which means they prevent bacterial adhesion and are blood compatible. Many parameters contribute to the degree of biocompatibility. This paper discusses the mechanism of the formation of biofilms and lists the factors that influence the bacterial adhesion and haemocompatibility. Polymer surfaces are also modified to enhance adsorption of host cells. The physical, chemical and biological techniques are meant to modify the surface of the biomaterial but at the same time retain the key properties. The various polymer treatment processes have advantages and disadvantages and a few techniques have been proved to be both highly effective at treatment and found suitable for various in vivo environments. The current research focus pertaining to smart materials, biodegradable polymers, combinatorial chemistry, computational modelling and newer analytical techniques to understand polymer-cell interaction holds promise in designing better, cost effective and biocompatible polymers

  19. In vitro and in vivo ocular biocompatibility of electrospun poly(ɛ-caprolactone) nanofibers.

    OpenAIRE

    Da Silva G.R.; Lima T.H.; Oréfice R.L.; Fernandes-Cunha G.M.; Silva-Cunha A.; Zhao M; Behar-Cohen F.

    2015-01-01

    Biocompatibility is a requirement for the development of nanofibers for ophthalmic applications. In this study, nanofibers were elaborated using poly(ε-caprolactone) via electrospinning. The ocular biocompatibility of this material was investigated. MIO-M1 and ARPE-19 cell cultures were incubated with nanofibers and cellular responses were monitored by viability and morphology. The in vitro biocompatibility revealed that the nanofibers were not cytotoxic to the ocular cells. These cells ...

  20. Achievement report for fiscal 1990 on research and development of electrically conductive polymeric materials; 1990 nendo dodensei kobunshi zairyo no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-03-01

    It is intended to realize new electrically conductive materials characterized by light weight, corrosion resistance and easy-to-process performance, and electrical and electronic materials having functions different from those of metallic conduction mechanism. Therefore, activities were performed to seek technologies for polymeric materials having conductivity greater than 10{sup 5} S/cm and being stable and easy to process. Activities were taken in the following six fields: (1) new hydrocarbon conjugate polymers, (2) excipient conjugate conductive materials, (3) technologies to form thin films of graphite synthesized at low temperatures, (4) conductive polymers of hetero aromatic system, (5) research and development of conductive materials of the hetero containing system and the {pi} conjugate system, and (6) comprehensive investigative research. In (1), thin films of polyacetylene and polyacene systems were formed, in (2), excipient hydrocarbon conjugate polymers and excipient graphite materials were developed, in (3), a high-accuracy process controlled graphite thin film forming technology was developed, in (4), the conductivity was enhanced by using high-order structural control and molecular design, and stability of the conductive polymers of complex annular conjugate system was enhanced, and in (5), conductive polymers of the hetero containing system and the {pi} conjugate system, and flexible graphite fibers were developed. (NEDO)

  1. Introduction of Bifunctional Group onto MWNT by Radiation-Induced Graft Polymerization and Its Use as Biosensor-Supporting Materials

    International Nuclear Information System (INIS)

    A biosensor comprising tyrosinase immobilized on bi functionalized multi walled carbon nano tube (MWNT) supports was prepared for the detection of phenolic compounds in drinks such as red wine and juices. The MWNT supports were prepared by radiation-induced graft polymerization (RIGP) of epoxy-containing glycidyl methacrylate (GMA), to covalently immobilize the tyrosinase, and vinyl ferrocene (VF), which can act as an electron transfer mediator via redox reactions. The bi functionalized MWNTs were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). Electrodes prepared with the MWNTs showed increased current with increasing VF content. A biosensor comprising tyrosinase immobilized on the bi functionalized MWNTs could detect phenol at 0.1 - 20 mM. Phenolics in red wine and juices were determined using the biosensor after its calibration.

  2. A comprehensive study of soft magnetic materials based on FeSi spheres and polymeric resin modified by silica nanorods

    International Nuclear Information System (INIS)

    A novel soft magnetic composite (SMC) based on spherical FeSi particles precisely covered by hybrid phenolic resin was designed. The hybrid resin including silica nano-rods chemically incorporated into the phenolic polymer matrix was prepared by the modified sol–gel method. A chemical bridge connecting silica nano-rods with the base polymeric net was verified by FTIR, 13C and 29Si NMR spectroscopy, whereas the shape and size of silica nano-rods were determined by TEM. It is shown that the modification of polymeric resin by silica nano-rods generally leads to the improved thermal and mechanical properties of the final samples. The hybrid resin serves as a perfect insulating coating deposited on FeSi particles and the core–shell particles can be further compacted by standard powder metallurgy methods in order to prepare final samples for mechanical, electric and magnetic testing. SEM images evidence negligible porosity, uniform distribution of the hybrid resin around FeSi particles, as well as, dimensional shape stability of the final samples after thermal treatment. The hardness, flexural strength and density of the final samples are comparable to the sintered SMCs, but they simultaneously exhibit much higher specific resistivity along with only slightly lower coercivity and permeability. - Highlights: • Soft magnetic composites are designed for electrotechnical applications. • Electroinsulating layer consists of phenolic resin modified with silica nano-rods. • NMR, FTIR and DSC analysis is used to characterize hybrid resin. • Spherical Fe–Si particles covered by hybrid resin form a core–shell composite. • Mechanical, electrical and magnetic properties are described in detail

  3. Synthesis of Narrow Molecular Weight Distribution Norbornene-Lactone Functionalized Polymers by Nitroxide-Mediated Polymerization: Candidates for 193-nm Photoresist Materials

    Directory of Open Access Journals (Sweden)

    Zi Jun Wang

    2014-02-01

    Full Text Available One hundred ninety three-nanometer candidate photoresist materials were synthesized by nitroxide-mediated polymerization (NMP. Statistical copolymerizations of 5-methacryloyloxy-2,6-norboranecarbolactone (NLAM with 5–10 mol% of controlling co-monomers (which are necessary for controlled polymerizations of methacrylates by NMP with the initiator used in the feed, such as styrene (ST, p-acetoxystyrene (AcOST, 2-vinyl naphthalene (VN and pentafluorostyrene (PFS, using the unimolecular BlocBuilder® initiator in 35 wt% dioxane solution at 90 °C were performed. As little as 5 mol% controlling comonomer in the feed was demonstrated to be sufficient to lead to linear evolution of number average molecular weight  with respect to conversion up to 50%, and the resulting copolymers had dispersities  of ~1.3 in most cases, an attractive feature for reducing line width roughness (LWR in photoresists. The copolymers generally showed relatively low absorbance at 193 nm, comparable to other 193-nm candidate photoresists reported previously, despite the inclusion of a small amount of the styrenic co-monomers in the copolymer.

  4. Patenteamento em nanotecnologia: estudo do setor de materiais poliméricos nanoestruturados Patenting in nanotechnology: study of nanostructurated polymeric materials sector

    Directory of Open Access Journals (Sweden)

    Suzana Borschiver

    2005-11-01

    Full Text Available Neste trabalho foi feito um estudo de tendências tecnológicas em nanotecnologia aplicado ao setor de materiais poliméricos, com base em informações extraídas de documentos de patentes. Foi usada como fonte de dados o banco de patentes da USPTO (United States Patent Trademark Office. Os dados foram obtidos via web, utilizando-se diversas palavras-chaves Foram mapeados os principais países depositantes, tipo de depositante e ano de aplicação, setores de aplicação, tipos de polímeros utilizados e principais aditivos e cargas incorporados às matrizes poliméricas.In this work a study of technological tendencies in nanotechnology applied to polymeric materials sector was carried out, based on information extracted of paten documents. The patent office of USPTO (United States Patent Trademark Office was used as a data source. The data were supplied via web, using several keywords. A mapping was made of the major countries contributing, types and year of patent deposition, application sectors, polymer types used, main additives and fillers incorporated to the polymeric matrices.

  5. In vivo biocompatibility of nanostructured Chitosan/Peo membranes

    Directory of Open Access Journals (Sweden)

    V.A.S. Vulcani

    2015-08-01

    Full Text Available Electrospinning is a technique that allows the preparation of nanofibers from various materials. Chitosan is a natural and abundant easily obtained polymer, which, in addition to those features, proved to be biocompatible. This work used nanostructured chitosan and polyoxyethylene membranes as subcutaneous implants in Wistar rats to evaluate the biocompatibility of the material. Samples of the material and tissues adjacent to the implant were collected 7, 15, 30, 45 and 60 days post-implantation. Macroscopic integration of the material to the tissues was observed in the samples and slides for histopathological examination that were prepared. It was noticed that the material does not stimulate the formation of adherences to the surrounding tissues and that there is initial predominance of neutrophilia and lymphocytosis, with a declining trend according to the increase of time, featuring a non-persistent acute inflammatory process. However, the material showed fast degradation, impairing the macroscopic observation after fifteen days of implantation. It was concluded that the material is biocompatible and that new studies should be conducted, modifying the time of degradation by changes in obtaining methods and verifying the biocompatibility in specific tissues for biomedical applications.

  6. The surface alloying effect of silicon in a binary NiTi-base alloy on the corrosion resistance and biocompatibility of the material

    Science.gov (United States)

    Psakhie, S. G.; Lotkov, A. I.; Meisner, L. L.; Meisner, S. N.; Matveeva, V. A.

    2013-02-01

    The corrosion resistance behavior and cytotoxicity of binary NiTi-base alloy specimens subjected to surface modification by silicon ion beams and the proliferative ability of mesenchymal stem cells of rat marrow on an ion-implanted surface of the alloy have been studied. The silicon ion beam processing of specimen surfaces is shown to bring about a nearly two-fold improvement in the corrosion resistance of the material to attack by aqueous solutions of NaCl (artificial body fluid) and human plasma and a drastic decrease in the nickel concentration after immersion of the specimens into the solutions for ˜3400 and ˜6000 h, respectively (for the artificial plasma solution, a nearly 20-fold decrease in the Ni concentration is observed.)

  7. Thermally Stable, Piezoelectric and Pyroelectric Polymeric Substrates

    Science.gov (United States)

    Simpson, Joycely O. (Inventor); St.Clair, Terry L. (Inventor)

    1999-01-01

    A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared. This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers. acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors, in-situ temperature sensors, in-situ stress/strain sensors, micro actuators, switches, adjustable fresnel lenses, speakers, tactile sensors. weather sensors, micro positioners, ultrasonic devices, power generators, tunable reflectors, microphones, and hydrophones. The process for preparing these polymeric substrates includes: providing a polymeric substrate having a softening temperature greater than 1000 C; depositing a metal electrode material onto the polymer film; attaching a plurality of electrical leads to the metal electrode coated polymeric substrate; heating the metal electrode coated polymeric substrate in a low dielectric medium; applying a voltage to the heated metal electrode coated polymeric substrate to induce polarization; and cooling the polarized metal electrode coated polymeric electrode while maintaining a constant voltage.

  8. Immobilization of biocatalysts for enzymatic polymerizations : Possibilities, advantages, applications

    NARCIS (Netherlands)

    Miletic, Nemanja; Nastasovic, Aleksandra; Loos, Katja; Miletić, Nemanja; Nastasović, Aleksandra

    2012-01-01

    Biotechnology also holds tremendous opportunities for realizing functional polymeric materials. Biocatalytic pathways to polymeric materials are an emerging research area with not only enormous scientific and technological promise, but also a tremendous impact on environmental issues. Many of the en

  9. Biocompatibility of polymethylmethacrylate resins used in dentistry.

    Science.gov (United States)

    Gautam, Rupali; Singh, Raghuwar D; Sharma, Vinod P; Siddhartha, Ramashanker; Chand, Pooran; Kumar, Rakesh

    2012-07-01

    Biocompatibility or tissue compatibility describes the ability of a material to perform with an appropriate host response when applied as intended. Poly-methylmethacrylate (PMMA) based resins are most widely used resins in dentistry, especially in fabrication of dentures and orthodontic appliances. They are considered cytotoxic on account of leaching of various potential toxic substances, most common being residual monomer. Various in vitro and in vivo experiments and cell based studies conducted on acrylic based resins or their leached components have shown them to have cytotoxic effects. They can cause mucosal irritation and tissue sensitization. These studies are not only important to evaluate the long term clinical effect of these materials, but also help in further development of alternate resins. This article reviews information from scientific full articles, reviews, or abstracts published in dental literature, associated with biocompatibility of PMMA resins and it is leached out components. Published materials were searched in dental literature using general and specialist databases, like the PubMED database. PMID:22454327

  10. A comprehensive study of soft magnetic materials based on FeSi spheres and polymeric resin modified by silica nanorods

    Czech Academy of Sciences Publication Activity Database

    Strečková, M.; Füzer, J.; Kobera, Libor; Brus, Jiří; Fáberová, M.; Bureš, R.; Kollár, P.; Lauda, M.; Medvecký, L.; Girman, V.; Hadraba, Hynek; Baťková, M.; Baťko, I.

    2014-01-01

    Roč. 147, č. 3 (2014), s. 649-660. ISSN 0254-0584 Institutional support: RVO:61389013 ; RVO:68081723 Keywords : composite materials * magnetic materials * chemical synthesis Subject RIV: CD - Macromolecular Chemistry; JH - Ceramics, Fire-Resistant Materials and Glass (UFM-A) Impact factor: 2.259, year: 2014

  11. An improved model to estimate trapping parameters in polymeric materials and its application on normal and aged low-density polyethylenes

    International Nuclear Information System (INIS)

    Trapping parameters can be considered as one of the important attributes to describe polymeric materials. In the present paper, a more accurate charge dynamics model has been developed, which takes account of charge dynamics in both volts-on and off stage into simulation. By fitting with measured charge data with the highest R-square value, trapping parameters together with injection barrier of both normal and aged low-density polyethylene samples were estimated using the improved model. The results show that, after long-term ageing process, the injection barriers of both electrons and holes is lowered, overall trap depth is shallower, and trap density becomes much greater. Additionally, the changes in parameters for electrons are more sensitive than those of holes after ageing

  12. An improved model to estimate trapping parameters in polymeric materials and its application on normal and aged low-density polyethylenes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ning, E-mail: nl4g12@soton.ac.uk; He, Miao; Alghamdi, Hisham; Chen, George [School of Electronic and Computer Science, University of Southampton, Southampton (United Kingdom); Fu, Mingli; Li, Ruihai; Hou, Shuai [Electric Power Research Institute of China Southern Power Grid, Guangzhou (China)

    2015-08-14

    Trapping parameters can be considered as one of the important attributes to describe polymeric materials. In the present paper, a more accurate charge dynamics model has been developed, which takes account of charge dynamics in both volts-on and off stage into simulation. By fitting with measured charge data with the highest R-square value, trapping parameters together with injection barrier of both normal and aged low-density polyethylene samples were estimated using the improved model. The results show that, after long-term ageing process, the injection barriers of both electrons and holes is lowered, overall trap depth is shallower, and trap density becomes much greater. Additionally, the changes in parameters for electrons are more sensitive than those of holes after ageing.

  13. The Cavity Problem in the Polymeric Electronic Packaging Material%一类高聚物电子封装材料中的空穴问题

    Institute of Scientific and Technical Information of China (English)

    李志刚; 王慧明; 树学峰

    2013-01-01

    The cavity formation in the generalized neo-Hookean polymeric packaging material with power rates strengthen feature after reinforcement is focused on, the cavity bifurcation theory in the hyperelastic material is used to demonstrate the analytic relationship between the generation and development of cavity in solder-reflow process for this specific packaging material and heat stress. The effects of reinforcing fibers which is added into this material on the model of cavity development are taken into consideration. The influences of reinforce coefficient y and hardening coefficient n after reinforcing on the cavity development are also discussed. The results show that for the electronic package material with reinforcement if the hardening coefficient in energy storage function is even, the limit load for cavity instability will increase with the reinforce coefficient. On the contrary, if the hardening coefficient is odd number, the limit load will decrease as the reinforce coefficient increase,"popcorn" failure can occur more easily on the polymeric material with this kind of energy storage feature.%研究了补强后具有幂率强化特征的广义neo-Hookean的高聚物电子封装材料,利用超弹性材料空穴分叉的理论推导出了此类封装材料在回流焊过程中空穴的生成及增长与热应力之间的解析关系.同时考虑了高聚物电子封装材料添加补强纤维后对空穴增长模型产生的影响.讨论了补强系数γ,和补强后的硬化指数n对空穴增长的影响.分析结果表明:对于补强后的电子封装材料,如果储能函数中的硬化指数为偶数形式,则空穴失稳的极限载荷将伴随着补强系数的增大而增大;反之,如果为奇数形式,则极限载荷将伴随着补强系数的增大而降低,具有这种储能形式的高聚物材料更易发生“爆米花”式的失效.

  14. Design and fabrication of a new class of nano hybrid materials based on reactive polymeric molecular cages.

    Science.gov (United States)

    Zhang, De Suo; Liu, Xiang Yang; Li, Jing Liang; Xu, Hong Yao; Lin, Hong; Chen, Yu Yue

    2013-09-10

    This paper describes a strategy of fabricating a new class of nano hybrid particles in terms of the "nanocages" of reactive molecular matrices/networks. The concept is to design molecular matrices functionalized with particular reactive groups, which can on-site synthesize and fix nanoparticles at the designated positions of the molecular networks. The cages of the molecular networks impose the confinement and protection to the nanoparticles so that the size and the stability of nano hybrid particles can be better controlled. To this end, polyamide network polymers (PNP) were synthesized and adopted as the reactive molecular cages for the control of silver nanoparticles formation. It follows that the silver nano hybrid particles fabricated by this method have an average diameter of 4.34 nm much smaller than any other or similar methods ie by a hyperbranched polyamide polymer (HB-PA). As per our design, the size of the silver nano hybrid particles can also be tuned by controlling the molar ratio between silver ions and the functional groups in the polymeric matrices. The silver nano hybrid particles reveal the substantially enhanced stability in aqueous solutions, which gives rise to the long stable performance of localized surface plasmon resonance. As the nano hybrid particles display long eminent nanoeffects, they exert broad implications for a wide range of applications such as biomedicine, catalysis, and optoelectronics. PMID:23980927

  15. Adhesion of biocompatible and biodegradable micropatterned surfaces

    NARCIS (Netherlands)

    Kaiser, J.S.; Kamperman, M.M.G.; Souza, E.J.; Schick, B.; Arzt, E.

    2011-01-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PL

  16. 骨盆并髋臼骨折内固定材料的生物相容性%Materials biocompatibility in the internal fixation of pelvic fracture combined with acetabular fracture

    Institute of Scientific and Technical Information of China (English)

    高明杰; 陶杰; 周孜辉; 杜琳

    2015-01-01

    背景:骨盆骨折合并髋臼骨折多由高能量暴力伤所致,常伴严重并发症,往往需要外科内固定治疗。目的:探讨骨盆骨折合并髋臼骨折内固定治疗以及材料的生物相容性。方法:以“骨盆骨折,髋臼骨折,内固定,材料;pelvis fracture,acetabulum fracture,internal fixators, materials”为关键词,应用计算机检索2005至2014年万方数据库、清华知网数据库和PubMed数据库,选取有关骨盆骨折合并髋臼骨折内固定治疗以及材料生物相容性研究的文献,同一领域文献选择权威杂志或发表时间为近期的文章,依据纳入排除标准选取29篇文献进行归纳分析。结果与结论:对于骨盆骨折合并髋臼骨折临床多采用重建钢板或拉力螺钉内固定,常用于内固定的重建钢板材料是钛板,弹性模量接近骨的弹性模量,生物相容性好,可在置入前预先弯曲塑形,使之与骨折部位骨面相匹配。可吸收螺钉具有良好的组织相容性,无毒副反应,避免金属螺钉的电解与腐蚀,在内固定早期保持一定的强度,随着时间的推移骨折逐渐愈合,材料强度也缓慢降低,材料最终降解为水和二氧化碳,治疗效果满意。以三维重建技术定制钢板固定和微创内固定是目前骨折治疗的重大进展,临床应用前景广阔。%BACKGROUND:Pelvic fractures combined with acetabular fractures are mostly caused by high-energy violence, often accompanied by severe complications and high mortality, and surgical fixation is preferred in most cases. OBJECTIVE:To investigate the internal fixation of pelvic fracture combined with acetabular fracture and to analyze the material biocompatibility. METHODS:A computer-based search of Wanfang, CNKI and PubMed databases was performed for articles related to the internal fixation of pelvic fracture combined with acetabular fracture and material biocompatibility published

  17. Biocompatibility of Bacterial Cellulose Based Biomaterials

    Directory of Open Access Journals (Sweden)

    Omar P. Troncoso

    2012-12-01

    Full Text Available Some bacteria can synthesize cellulose when they are cultivated under adequate conditions. These bacteria produce a mat of cellulose on the top of the culture medium, which is formed by a three-dimensional coherent network of pure cellulose nanofibers. Bacterial cellulose (BC has been widely used in different fields, such as the paper industry, electronics and tissue engineering due to its remarkable mechanical properties, conformability and porosity. Nanocomposites based on BC have received much attention, because of the possibility of combining the good properties of BC with other materials for specific applications. BC nanocomposites can be processed either in a static or an agitated medium. The fabrication of BC nanocomposites in static media can be carried out while keeping the original mat structure obtained after the synthesis to form the final nanocomposite or by altering the culture media with other components. The present article reviews the issue of biocompatibility of BC and BC nanocomposites. Biomedical aspects, such as surface modification for improving cell adhesion, in vitro and in vivo studies are given along with details concerning the physics of network formation and the changes that occur in the cellulose networks due to the presence of a second phase. The relevance of biocompatibility studies for the development of BC-based materials in bone, skin and cardiovascular tissue engineering is also discussed.

  18. Frontal Polymerization in Microgravity

    Science.gov (United States)

    Pojman, John A.

    1999-01-01

    Frontal polymerization systems, with their inherent large thermal and compositional gradients, are greatly affected by buoyancy-driven convection. Sounding rocket experiments allowed the preparation of benchmark materials and demonstrated that methods to suppress the Rayleigh-Taylor instability in ground-based research did not significantly affect the molecular weight of the polymer. Experiments under weightlessness show clearly that bubbles produced during the reaction interact very differently than under 1 g.

  19. Biocompatibility of dental alloys

    Energy Technology Data Exchange (ETDEWEB)

    Braemer, W. [Heraeus Kulzer GmbH and Co. KG, Hanau (Germany)

    2001-10-01

    Modern dental alloys have been used for 50 years to produce prosthetic dental restorations. Generally, the crowns and frames of a prosthesis are prepared in dental alloys, and then veneered by feldspar ceramics or composites. In use, the alloys are exposed to the corrosive influence of saliva and bacteria. Metallic dental materials can be classified as precious and non-precious alloys. Precious alloys consist of gold, platinum, and small amounts of non-precious components such as copper, tin, or zinc. The non-precious alloys are based on either nickel or cobalt, alloyed with chrome, molybdenum, manganese, etc. Titanium is used as Grade 2 quality for dental purposes. As well as the dental casting alloys, high purity electroplated gold (99.8 wt.-%) is used in dental technology. This review discusses the corrosion behavior of metallic dental materials with saliva in ''in vitro'' tests and the influence of alloy components on bacteria (Lactobacillus casei and Streptococcus mutans). The test results show that alloys with high gold content, cobalt-based alloys, titanium, and electroplated gold are suitable for use as dental materials. (orig.)

  20. Assessment of thermal damage to polymeric materials by hydrogen deflagration in the Three Mile Island Unit 2 Reactor Building

    International Nuclear Information System (INIS)

    Thermal damage to susceptible material in accessible regions of the reactor building was distributed in non-uniform patterns. No clear explanation for non-uniformity was found in examined evidence, e.g., burned materials were adjacent to materials that appear similar but were not burned. Because these items were in proximity to vertical openings that extend the height of the reactor building, we assume the unburned materials preferentially absorbed water vapor during periods of high, local steam concentration. Simple hydrogen-fire-exposure tests and heat transfer calculations duplicate the degree of damage found on inspected materials from the containment building. These data support estimated 8% pre-fire hydrogen concentration predictions based on various hydrogen production mechanisms

  1. Electroactivity and biocompatibility of polypyrrole-hyaluronic acid multi-walled carbon nanotube composite.

    Science.gov (United States)

    Pelto, Jani; Haimi, Suvi; Puukilainen, Esa; Whitten, Philip G; Spinks, Geoffrey M; Bahrami-Samani, Mehrdad; Ritala, Mikko; Vuorinen, Tommi

    2010-06-01

    Electroactivity of polypyrrole hyaluronic acid, electropolymerized in the presence of oxidized carbon nanotubes (PPyHA-CNT) was studied in situ by electrochemical atomic force microscopy (EC-AFM) in physiological electrolyte solution. In situ Raman spectroscopic and quartz crystal microbalance (QCM) studies were conducted on layers of the polymer grown on AT-cut 5 MHz quartz crystals. Human adipose stem cell (ASC) attachment and viability were studied by Live/Dead staining, and the proliferation was evaluated by WST-1 Cell proliferation assay for polypyrrole samples electropolymerized on titanium. According to cyclic voltammetry, the measured specific capacitance of the material on gold is roughly 20% of the reference polypyrrole dodecylbenzene sulfonate (PPyDBS). Electrochemical-QCM (EC-QCM) analysis of a 210-nm thick film reveals that the material is very soft G' approximately 100 kPa and swells upon reduction. EC-AFM of samples polymerized on microelectrodes show that there are areas of varying electroactivity, especially for samples without a hydrophopic backing PPyDBS layer. AFM line scans show typically 20-25% thickness change during electrochemical reduction. Raman spectroscopic analysis suggests that the material supports noticeable polaron conduction. Biocompatibility study of the PPyHA-CNT on titanium with adipose stem cells showed equal or better cell attachment, viability, and proliferation compared with the reference polylactide. PMID:19753624

  2. Development of Nano-Particles Within Polymeric Materials Prepared by Gamma Radiation and their Possible Practical Applications

    International Nuclear Information System (INIS)

    Nanoparticles can be used in biomedical applications, where they facilitate laboratory diagnostics, or in medical drug targeting nanoparticles based on a core consisting of iron oxides that can be targeted through external magnets. Polyvinyl alcohol/Polyacrylic acid nanoparticles were prepared using gamma rays. The prepared PVA/AAc nano copolymers were treated with Fe2+/ Fe3+ solution followed by ammonia solution to obtain PVA/AAc-Fe3O4 nanoparticle ferrogel. Characterization of the PVA/AAc-Fe3O4 nanoparticle ferrogel was carried out using XRD, TGA, DSc , TEM and AFM. The use of magnetic field sensitive nano-ferrogels as a drug carrier was investigated. It was found that the release of drug in absence of the effect of magnetic field is mostly slow than that under the influence of magnetic field. On the other hand, development of nanoparticles within radiation grafted polymeric surfaces using electroless plating technique was investigated. Surface modification of polypropylene films (PP) was carried out via radiation induced graft copolymerization of 4-vinyl pyridine (4VP) and acrylamide (AAm) to enhance the adhesion ability of the PP surface for electroless deposition of copper. The produced grafted films were characterized by studying their FTIR and thermal stability. The prepared grafted films were copper-plated by electroless deposition using the Pd as a catalyst to initiate the redox reaction. The influences of catalytic activation method parameters on the plating rate have been studied. The electrical characteristics of the copper plated films in comparison with grafted films were studied. The results showed the high adhesion of the deposited copper film to the grafted PP film as well as high electrical conductivity. (author)

  3. Donor-π-bridge-acceptor type polymeric materials with pendant electron-withdrawing groups for electrochromic applications

    International Nuclear Information System (INIS)

    Highlights: • Donor-π-bridge-acceptor copolymers with different electrophilic groups were synthesized. • Electrochromic devices composed of PBDTTPAs layers, as the working electrode, and vanadium pentoxide, as the counter electrode, were fabricated and evaluated. • The PBDTTPA-CHO film and device show multicolor electrochromic behavior which exhibited vivid yellow, green, and gray with better electrochromic performance than PBDTTPA-COOH. - Abstract: A novel donor-π-bridge-acceptor copolymer, PBDTTPA-CHO, containing 4-(Bis(4-bromophenyl)-amino)benzaldehyde (TPA-CHO) and 4,8-bis-(2-ethyl- hexyloxy)-oxybenzo-[1,2-b:3,4-b’]dithiophene (BDT), was successfully synthesized using Stille coupling polymerization, and the pendant aldehyde group was modified with cyanoacetic acid to synthesize another polymer, PBDTTPA-COOH. Each of these new polymers are soluble in organic solvents and can be cast onto rigid or flexible substrates. The polymers with different electrophilic groups exhibit different electrochromic behaviors, including different colors, driving voltages and transmittances. The polymer film of PBDTTPA-CHO manifests reversible electrochemical oxidation and reduction accompanied by multicolor changes from its yellow neutral state to a highly absorbent green semi-oxidized state and a gray fully oxidized state, its transmittance change at 601 nm is 43%. PBDTTPA-COOH switches between orange and light green. We fabricated and evaluated electrochromic devices using a PBDTTPA layer as the working electrode and vanadium pentoxide as the counter electrode. With the contribution of counter electrodes, devices of both polymers show similar color changes but higher transmittance than their films

  4. Ethylene polymerization and polyethylene functionalization

    OpenAIRE

    Marín Càmara, Ariadna

    2010-01-01

    Polyolefins have become ubiquitous and are large volume commodity materials. Of current interest is the preparation of speciality polymers incorporating polyethylene (PE), which often requires polymer chain-end manipulation. Ethylene polymerization by a neodymium catalyst in conjunction with n-butyloctylmagnesium (BOMg) is based on a reversible chain-transfer between Nd (where PE chains grow) and Mg (where PE chains rest). Using a large BOMg/Nd ratio for ethylene polymerization leads to m...

  5. Biocompatible fluorescent nanoparticles for in vivo stem cell tracking

    International Nuclear Information System (INIS)

    Efficient application of stem cells to the treatment of neurodegenerative diseases requires safe cell tracking to follow stem cell fate over time in the host environment after transplantation. In this work, for the first time, fluorescent and biocompatible methyl methacrylate (MMA)-based nanoparticles (fluoNPs) were synthesized through a free-radical co-polymerization process with a fluorescent macromonomer obtained by linking Rhodamine B and hydroxyethyl methacrylate. We demonstrate that the fluoNPs produced by polymerization of MMA–Rhodamine complexes (1) were efficient for the labeling and tracking of multipotent human amniotic fluid cells (hAFCs); (2) did not alter the main biological features of hAFCs (such as viability, cell growth and metabolic activity); (3) enabled us to determine the longitudinal bio-distribution of hAFCs in different brain areas after graft in the brain ventricles of healthy mice by a direct fluorescence-based technique. The reliability of our approach was furthermore confirmed by magnetic resonance imaging analyses, carried out by incubating hAFCs with both superparamagnetic iron oxide nanoparticles and fluoNPs. Our data suggest that these finely tunable and biocompatible fluoNPs can be exploited for the longitudinal tracking of stem cells. (paper)

  6. PEGylation of carbon nanotubes via mussel inspired chemistry: Preparation, characterization and biocompatibility evaluation

    International Nuclear Information System (INIS)

    Graphical abstract: Water dispersible and biocompatible PEGylated carbon nanotubes were prepared via a novel mussel inspired strategy for the first time. - Highlights: • Surface modification of CNTs via bioinspired chemistry. • CNTs with high water dispersibility and excellent biocompatibility. • PEGytion of CNTs via Michael addition reaction. • Preparation of aminated PEG molecules via chain transfer polymerization. - Abstract: A novel strategy for surface modification of multi-walled carbon nanotubes (MWCNT) was developed via combination of mussel inspired chemistry and Michael addition reaction. In this procedure, pristine MWCNT were first coated with polydopamine (PDA) through self polymerization of dopamine. The PDA functionalized CNT (CNT-PDA) were further functionalized with amino-terminated polymers (polyPEGMA), which were synthesized via free radical polymerization using cysteamine hydrochloride as the chain transfer agent and poly(ethylene glycol) monomethyl ether methacylate as the monomer. The successful modification of CNT was ascertained by a series of characterization techniques including transmission electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis and X-ray photoelectron spectrometry. The polymer modified CNT showed enhanced dispersibility in aqueous and organic solution. Cytotoxicity evaluation of polymers modified CNT showed that these modified CNT are biocompatible with cells. Finally, due to the universal adhesive of PDA and chain transfer free radical polymerization, this strategy developed in this work can also be extended for surface modification of many other nanomaterials with different functional polymers

  7. PEGylation of carbon nanotubes via mussel inspired chemistry: Preparation, characterization and biocompatibility evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoyong; Zeng, Guangjian; Tian, Jianwen; Wan, Qing; Huang, Qiang [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wang, Ke; Zhang, Qingsong [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing 100084 (China); Liu, Meiying; Deng, Fengjie [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wei, Yen, E-mail: xiaoyongzhang1980@gmail.com [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing 100084 (China)

    2015-10-01

    Graphical abstract: Water dispersible and biocompatible PEGylated carbon nanotubes were prepared via a novel mussel inspired strategy for the first time. - Highlights: • Surface modification of CNTs via bioinspired chemistry. • CNTs with high water dispersibility and excellent biocompatibility. • PEGytion of CNTs via Michael addition reaction. • Preparation of aminated PEG molecules via chain transfer polymerization. - Abstract: A novel strategy for surface modification of multi-walled carbon nanotubes (MWCNT) was developed via combination of mussel inspired chemistry and Michael addition reaction. In this procedure, pristine MWCNT were first coated with polydopamine (PDA) through self polymerization of dopamine. The PDA functionalized CNT (CNT-PDA) were further functionalized with amino-terminated polymers (polyPEGMA), which were synthesized via free radical polymerization using cysteamine hydrochloride as the chain transfer agent and poly(ethylene glycol) monomethyl ether methacylate as the monomer. The successful modification of CNT was ascertained by a series of characterization techniques including transmission electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis and X-ray photoelectron spectrometry. The polymer modified CNT showed enhanced dispersibility in aqueous and organic solution. Cytotoxicity evaluation of polymers modified CNT showed that these modified CNT are biocompatible with cells. Finally, due to the universal adhesive of PDA and chain transfer free radical polymerization, this strategy developed in this work can also be extended for surface modification of many other nanomaterials with different functional polymers.

  8. Chain Reaction Polymerization.

    Science.gov (United States)

    McGrath, James E.

    1981-01-01

    The salient features and importance of chain-reaction polymerization are discussed, including such topics as the thermodynamics of polymerization, free-radical polymerization kinetics, radical polymerization processes, copolymers, and free-radical chain, anionic, cationic, coordination, and ring-opening polymerizations. (JN)

  9. Assessment of Extent and Degree of Thermal Damage to Polymeric Materials in the Three Mile Island Unit 2 Reactor Building

    International Nuclear Information System (INIS)

    Thermal damage to susceptible materials in accessible regions of the TMI-2 reactor building shows damage-distribution patterns that indicate non-uniform intensity of exposure. No clear explanation for non-uniformity is found in existing evidence; e.g., in some regions a lack of thermally susceptible materials frustrates analysis. Elsewhere, burned materials are present next to materials that seem similar but appear unscathed-leading to conjecture that the latter materials preferentially absorb water vapor during periods of high local steam concentration. Most of the polar crane pendant shows heavy burns on one half of its circumferential surface. This evidence suggests that the polar crane pendant side that experienced heaviest burn damage was exposed to intense radiant energy from a transient fire plume in the reactor containment volume. Tests and simple heat-transfer calculations based on pressure and temperature records from the accident show that the atmosphere inside the reactor building was probably 8% hydrogen in air, a value not inconsistent with the extent of burn damage. Burn-pattern geography indicates uniform thermal exposure in the dome volume to the 406-ft level (about 6 ft below the polar crane girder), partial thermal exposure in the volume between the 406- and 347-ft levels as indicated by the polar crane cable, and lack of damage to most thermally susceptible materials in the west quadrant of the reactor building; some evidence of thermal exposure Is seen in the free volume between the 305- and 347-ft levels. (author)

  10. Radiation chemical technology for production of polymeric hydrogels for medical purposes

    International Nuclear Information System (INIS)

    Full text: Polymeric hydrogels are water-swelling cross-linked hydrophilic polymers with ability to store reversibly great amount of water (more than 1000 g of water per 1 g of dry polymer). At present they found a lot of different applications in highly developed countries in science and industry. The set of unique physicochemical and biomedical properties (regulated sorption ability in respect to water and biological liquids, biocompatibility, soft tissue state, permeability in respect to small and big molecules, non-toxicity, etc.) allows their application in medicine. According to the clinical data there are no materials that can compete with hydrogels in development of endo-prostheses of soft-tissues in surgery, contact lenses for eyesight correction, hemo-compatible materials, novel for treatment of wounds and burns, targeted drug delivery systems. Polymeric hydrogels today practically substitute the traditional hydrophobic bases (Vaseline, lanolin) in technology of drug forms for development of ointments and dressings, containing natural and synthetic physiologically active substances. The advantages of hydrogels in comparison with hydrophobic analogues are obvious due to the drainage effect, homogenous distribution of drugs, better contact with wound, painless removing by water washing. The polymeric hydrogels are not produced in Kazakhstan in spite of the big source of raw materials. The aim of the present work is the development of radiation-chemical technology and development of polymeric biomedical hydrogels production based on raw materials of Kazakhstan. The novel types of polymeric hydrogel materials are developed by the authors of the report based on vinyl ethers of glycols, which produced in 'Alash Ltd.' (Temirtau). The great fundamental information content has been obtained about these monomers and polymers including direct quantitative data of their structure formation mechanism and physicochemical properties. These data served as a basis for

  11. Preparation of a biocompatible magnetic film from an aqueous ferrofluid

    International Nuclear Information System (INIS)

    Very promising nanoparticles for biomedical applications or in medical drug targeting are superparamagnetic nanoparticles based on a core consisting of iron oxides (SPION) that can be targeted through external magnets. Polyvinyl alcohol (PVA) is a unique synthetic biocompatible polymer that can be chemically cross-linked to form a gel. Biotechnology applications of magnetic gels include biosensors, targeted drug delivery, artificial muscles and magnetic buckles. These gels are produced by incorporating magnetic materials in the polymer composites. In this paper we report the synthesis of an aqueous ferrofluid and the preparation of a biocompatible magnetic gel with polyvinyl alcohol and glutharaldehyde (GTA). HClO4 was used to induce the peptization since this kind of ferrofluid does not have surfactant. The magnetic gel was dried to generate a biocompatible film

  12. Preparation of a biocompatible magnetic film from an aqueous ferrofluid

    Science.gov (United States)

    Albornoz, Cecilia; Jacobo, Silvia E.

    2006-10-01

    Very promising nanoparticles for biomedical applications or in medical drug targeting are superparamagnetic nanoparticles based on a core consisting of iron oxides (SPION) that can be targeted through external magnets. Polyvinyl alcohol (PVA) is a unique synthetic biocompatible polymer that can be chemically cross-linked to form a gel. Biotechnology applications of magnetic gels include biosensors, targeted drug delivery, artificial muscles and magnetic buckles. These gels are produced by incorporating magnetic materials in the polymer composites. In this paper we report the synthesis of an aqueous ferrofluid and the preparation of a biocompatible magnetic gel with polyvinyl alcohol and glutharaldehyde (GTA). HClO 4 was used to induce the peptization since this kind of ferrofluid does not have surfactant. The magnetic gel was dried to generate a biocompatible film.

  13. BIOCOMPATIBILITY EVALUATION OF XANTHAN/CHONDROITIN SULFATE HYDROGELS

    Directory of Open Access Journals (Sweden)

    Ana-Maria Oprea

    2012-03-01

    Full Text Available The in vitro and in vivo biocompatibility of xanthan/chondroitin sulfate hydrogels (X/CS in differentmixing ratios was investigated. The in vitro biocompatibility evaluation was performed by a chemiluminescent assayusing microorganisms such as Saccharomyces pombe. The cellular growth of S. pombe in presence of thexanthan/chondroitin sulfate hydrogels containing up to 20 % chondroitin sulfate was examinated comparatively withxanthan hydrogel.The in vivo evaluation was performed by toxicity test and subcutaneously implantation in rats. It has been establisheda lethal dose (LD50 bigger than 3200 mg/kg for all studied hydrogels, therefore they are nontoxic materials.The in vivo 30 days testing performed by subcutaneous implantation showed that the X/CS matrices were easilyabsorbed without side-effects, demonstrating their biocompatibility and effectiveness as potential drug delivery systems.

  14. Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Salafranca, Jesús, E-mail: fjsl@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Clemente, Isabel, E-mail: isabelclemente1984@gmail.com [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Isella, Francesca, E-mail: Francesca.Isella@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy); Nerín, Cristina, E-mail: cnerin@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Bosetti, Osvaldo, E-mail: Osvaldo.Bosetti@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy)

    2015-06-09

    Highlights: • 13 different food-use multilayers unirradiated and gamma-irradiated were studied. • 60–80 compounds/sample were identified by SPME–GC–MS even after 8-month storage. • Volatile profile of air- and N{sub 2}-filled bags greatly differed after irradiation. • Principal component analysis classified the samples into 4 groups. • Migration from irradiated materials to vapor phase was much lower than EU limits. - Abstract: The profile of volatile compounds released from 13 different multilayer polymeric materials for food use, before and after their exposure to gamma radiation, has been assessed by solid-phase microextraction–gas chromatography–mass spectrometry. Thermosealed bags of different materials were filled with either air or nitrogen to evaluate the oxygen influence. One-third of the samples were analyzed without irradiation, whereas the rest were irradiated at 15 and 25 kGy. Half of the samples were processed just after preparation and the other half was stored for 8 months at room temperature prior to analysis. Very significant differences between unirradiated and irradiated bags were found. About 60–80 compounds were released and identified per sample. A huge peak of 1,3-ditertbutylbenzene was present in most of the irradiated samples. An outstanding reproducibility in all the variables evaluated (chromatograms, oxygen percentage, volume of bags) was noticed. Independently of filling gas, the results of unirradiated materials were almost identical. In contrast, the chromatographic profile and the odor of irradiated bags filled with nitrogen were completely different to those filled with air. Principal component analysis was performed and 86.9% of the accumulated variance was explained with the first two components. The migration of compounds from irradiated materials to the vapor phase was much lower than the limits established in the Commission Regulation (EU) No 10/2011.

  15. Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation

    International Nuclear Information System (INIS)

    Highlights: • 13 different food-use multilayers unirradiated and gamma-irradiated were studied. • 60–80 compounds/sample were identified by SPME–GC–MS even after 8-month storage. • Volatile profile of air- and N2-filled bags greatly differed after irradiation. • Principal component analysis classified the samples into 4 groups. • Migration from irradiated materials to vapor phase was much lower than EU limits. - Abstract: The profile of volatile compounds released from 13 different multilayer polymeric materials for food use, before and after their exposure to gamma radiation, has been assessed by solid-phase microextraction–gas chromatography–mass spectrometry. Thermosealed bags of different materials were filled with either air or nitrogen to evaluate the oxygen influence. One-third of the samples were analyzed without irradiation, whereas the rest were irradiated at 15 and 25 kGy. Half of the samples were processed just after preparation and the other half was stored for 8 months at room temperature prior to analysis. Very significant differences between unirradiated and irradiated bags were found. About 60–80 compounds were released and identified per sample. A huge peak of 1,3-ditertbutylbenzene was present in most of the irradiated samples. An outstanding reproducibility in all the variables evaluated (chromatograms, oxygen percentage, volume of bags) was noticed. Independently of filling gas, the results of unirradiated materials were almost identical. In contrast, the chromatographic profile and the odor of irradiated bags filled with nitrogen were completely different to those filled with air. Principal component analysis was performed and 86.9% of the accumulated variance was explained with the first two components. The migration of compounds from irradiated materials to the vapor phase was much lower than the limits established in the Commission Regulation (EU) No 10/2011

  16. Assessment of extent and degree of thermal damage to polymeric materials in the Three Mile Island Unit 2 reactor building

    International Nuclear Information System (INIS)

    This paper describes assumptions and procedures used to perform thermal damage analysis caused by post loss-of-coolant-accident (LOCA) hydrogen deflagration at Three Mile Island Unit 2 Reactor. Examination of available photographic evidence yields data on the extent and range of thermal and burn damage. Thermal damage to susceptible material in accessible regions of the reactor building was distributed in non-uniform patterns. No clear explanation for non-uniformity was found in examined evidence, e.g., burned materials were adjacent to materials that appear similar but were not burned. Because these items were in proximity to vertical openings that extend the height of the reactor building, the authors assume the unburned materials preferentially absorbed water vapor during periods of high, local steam concentration. A control pendant from the polar crane located in the top of the reactor building sustained asymmetric burn damage of decreasing degree from top to bottom. Evidence suggests the polar-crane pendant side that experienced heaviest damage was exposed to intense radiant energy from a transient fire plume in the reactor containment volume. Simple hydrogen-fire-exposure tests and heat transfer calculations approximate the degree of damage found on inspected materials from the containment building and support for an estimated 8% pre-fire hydrogen

  17. Assessment of extent and degree of thermal damage to polymeric materials in the Three Mile Island Unit 2 Reactor building

    International Nuclear Information System (INIS)

    This paper describes assumptions and procedures used to perform thermal damage analysis caused by post loss-of-coolant-accident (LOCA) hydrogen deflagration at Three Mile Island Unit 2 Reactor. Examination of available photographic evidence yields data on the extent and range of thermal and burn damage. Thermal damage to susceptible material in accessible regions of the reactor building was distributed in non-uniform patterns. No clear explanation for non-uniformity was found in examined evidence, e.g., burned materials were adjacent to materials that appear similar but were not burned. Because these items were in proximity to vertical openings that extend the height of the reactor building, we assume the unburned materials preferentially absorbed water vapor during periods of high, local steam concentration. A control pendant from the polar crane located in the top of the reactor building sustained asymmetric burn damage of decreasing degree from top to bottom. Evidence suggests the polar-crane pendant side that experienced heaviest damage was exposed to intense radiant energy from a transient fire plume in the reactor containment volume. Simple hydrogen-fire-exposure tests and heat transfer calculations approximate the degree of damage found on inspected materials from the containment building and support for an estimated 8% pre-fire hydrogen

  18. Biocompatibility of Ti-alloys for long-term implantation.

    Science.gov (United States)

    Abdel-Hady Gepreel, Mohamed; Niinomi, Mitsuo

    2013-04-01

    The design of new low-cost Ti-alloys with high biocompatibility for implant applications, using ubiquitous alloying elements in order to establish the strategic method for suppressing utilization of rare metals, is a challenge. To meet the demands of longer human life and implantation in younger patients, the development of novel metallic alloys for biomedical applications is aiming at providing structural materials with excellent chemical, mechanical and biological biocompatibility. It is, therefore, likely that the next generation of structural materials for replacing hard human tissue would be of those Ti-alloys that do not contain any of the cytotoxic elements, elements suspected of causing neurological disorders or elements that have allergic effect. Among the other mechanical properties, the low Young's modulus alloys have been given a special attention recently, in order to avoid the occurrence of stress shielding after implantation. Therefore, many Ti-alloys were developed consisting of biocompatible elements such as Ti, Zr, Nb, Mo, and Ta, and showed excellent mechanical properties including low Young's modulus. However, a recent attention was directed towards the development of low cost-alloys that have a minimum amount of the high melting point and high cost rare-earth elements such as Ta, Nb, Mo, and W. This comes with substituting these metals with the common low cost, low melting point and biocompatible metals such as Fe, Mn, Sn, and Si, while keeping excellent mechanical properties without deterioration. Therefore, the investigation of mechanical and biological biocompatibility of those low-cost Ti-alloys is highly recommended now lead towards commercial alloys with excellent biocompatibility for long-term implantation. PMID:23507261

  19. 3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic-organic hybrid perovskite solar cells.

    Science.gov (United States)

    Li, Wei; Otsuka, Munechika; Kato, Takehito; Wang, Yang; Mori, Takehiko; Michinobu, Tsuyoshi

    2016-01-01

    The ever increasing demand for clean energy has encouraged researchers to intensively investigate environmentally friendly photovoltaic devices. Inorganic-organic hybrid perovskite solar cells (PSCs) are very promising due to their potentials of easy fabrication processes and high power conversion efficiencies (PCEs). Designing hole-transporting materials (HTMs) is one of the key factors in achieving the high PCEs of PSCs. We now report the synthesis of two types of carbazole-based polymers, namely 3,6-Cbz-EDOT and 2,7-Cbz-EDOT, by Stille polycondensation. Despite the same chemical composition, 3,6-Cbz-EDOT and 2,7-Cbz-EDOT displayed different optical and electrochemical properties due to the different connectivity mode of the carbazole unit. Therefore, their performances as hole-transporting polymeric materials in the PSCs were also different. The device based on 2,7-Cbz-EDOT showed better photovoltaic properties with the PCE of 4.47% than that based on 3,6-Cbz-EDOT. This could be due to its more suitable highest occupied molecular orbital (HOMO) level and higher hole mobility. PMID:27559390

  20. 3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

    Science.gov (United States)

    Li, Wei; Otsuka, Munechika; Wang, Yang; Mori, Takehiko

    2016-01-01

    Summary The ever increasing demand for clean energy has encouraged researchers to intensively investigate environmentally friendly photovoltaic devices. Inorganic–organic hybrid perovskite solar cells (PSCs) are very promising due to their potentials of easy fabrication processes and high power conversion efficiencies (PCEs). Designing hole-transporting materials (HTMs) is one of the key factors in achieving the high PCEs of PSCs. We now report the synthesis of two types of carbazole-based polymers, namely 3,6-Cbz-EDOT and 2,7-Cbz-EDOT, by Stille polycondensation. Despite the same chemical composition, 3,6-Cbz-EDOT and 2,7-Cbz-EDOT displayed different optical and electrochemical properties due to the different connectivity mode of the carbazole unit. Therefore, their performances as hole-transporting polymeric materials in the PSCs were also different. The device based on 2,7-Cbz-EDOT showed better photovoltaic properties with the PCE of 4.47% than that based on 3,6-Cbz-EDOT. This could be due to its more suitable highest occupied molecular orbital (HOMO) level and higher hole mobility.

  1. Radiation induced crosslinking of poly(L-lactic acid) for making the polymeric materials having high thermal stability and improved mechanical properties

    International Nuclear Information System (INIS)

    Different poly(L-lactic acid) (PLLA) have been synthesized from L-lactic acid as well as L-lactide by direct polycondensation and ring opening polymerization. Depending on reaction time, the resulting products having viscosity average molecular weight ranging from 5 to 25,000 g.mol-1. Plasticization effects of some popular plasticizer, especially is polyethylene glycols (PEG) for the synthesized PLLA were determined. The results suggested that PEG 1000 is a good plasticizer with relative high plasticization effect. The crosslinking plasticized materials were prepared form the plasticized PLLA by irradiation with various radiation doses. The crosslinking structures were introduced in different formulation of PLLA/PEG/TAIC, the crosslinking density increased with radiation dose and seemed to be saturated at 50 kGy. The stable crosslinking structure inhibited the mobility for crystallization of PLLA chains, thermal stability of plasticized PLLA crosslinked with TAIC at 50 kGy become higher than that of initial PLLA with very small endothermic peak at its melting temperature. The stress-strain curves of the crosslinking plasticized PLLA showed that the toughness of the materials reduced but still higher than that of initial PLLA, whereas its tensile strength was much improved by radiation crosslinking. The results also revealed that the crosslinking plasticized PLLA can be completely degraded by proteinase K as well as microorganisms existing in compost. (author)

  2. Effect of chlorine dioxide gas on physical, thermal, mechanical, and barrier properties of p[olymeric packaging materials

    Science.gov (United States)

    In the first part of our study we determined permeability, diffusion, and solubility coefficients of gaseous chlorine dioxide (ClO2) through the following packaging material: biaxial-oriented polypropylene (BOPP); polyethylene terephthalate (PET); poly lactic acid (PLA); multilayer structure of ethy...

  3. Biocompatible and Bioeliminable Hydrophilic Polymers

    Institute of Scientific and Technical Information of China (English)

    Paolo; FerrutiUniversità

    2007-01-01

    1 Introduction This presentation will report on some recent results obtained in Milan on two polymer families of biomedical interest, namely poly(N-vinyl-2-pyrrolidinone) and polyamidoamines. 2 Results and DiscussionPoly(N-vinyl-2-pyrrolidinone) (PVP) is a well known bioactive and biocompatible polymer. In its soluble form, it is largely used as excipient of oral pharmaceutical formulations, especially for its high water solubilising power.In its crosslinked form, it plays a relevant role as biomateria...

  4. Synthesis of biocompatible polymers by plasma

    International Nuclear Information System (INIS)

    smallest contact angles. It has been demonstrated that the high energy of plasma in the polymers favors certain crystalline arrangement due to the reorganization of polymeric chains. In this work the crystallinity was calculated by means of areas under the curve of the amorphous and crystalline signals obtained by X-ray diffraction. The crystallinity in PPy/PEG increases from 8% to 9.5%. In Poly allylamine (PAl) the crystallinity was from 4% to 16%. The crystallinity in these materials increases when the increases synthesis energy. While in PPy the crystallinity diminishes from 16% to 12% when the synthesis energy increases, due to the fragmentation and/or possible ramifications of the pyrrole rings that reduce the formation of orderly regions with the energy increments. This characteristic is important, because they can be ended up forming conduction channels in the polymer that is reflected in the electric conductivity of the material. The electric conductivity is another important factor in this study, since due to the electric impulses generated among materials and cells it can stimulates the cellular growth. The electric response of the polymers was study in function of the relative humidity in the interval of 25-80% and in function of the volume of the solutions of NaCl, NaCl-MgSO4, and Krebs-Ringer. In the interval of 25-80% of relative humidity, the increment in the electric conductivity in PPy/PEG went from 10-12 to 10-10 S/cm at 25% and of 10-12 to 10-8 S/cm to 80% of relative humidity. The electric conductivity regarding the humidity in PAl increases from 10-11 of 10-9 S/cm to 25% and of 10-10 to 10-8 S/cm at 80%. In Poly pyrrole (PPy) and doped poly pyrrole with Iodine (PPy/I) one observes that the electric conductivity in the interval 25% to 80% of relative humidity went from 10-9 to 1011 S/cm in PPy and 10-8 and 10-10 S/cm in PPy/I almost increases two magnitude orders when increasing the relative humidity. The polymers showed a growing behavior in the

  5. Bioactive Polymeric Composites for Tooth Mineral Regeneration: Physicochemical and Cellular Aspects

    Directory of Open Access Journals (Sweden)

    Joseph M. Antonucci

    2011-09-01

    Full Text Available Our studies of amorphous calcium phosphate (ACP-based dental materials are focused on the design of bioactive, non-degradable, biocompatible, polymeric composites derived from acrylic monomer systems and ACP by photochemical or chemically activated polymerization. Their intended uses include remineralizing bases/liners, orthodontic adhesives and/or endodontic sealers. The bioactivity of these materials originates from the propensity of ACP, once exposed to oral fluids, to release Ca and PO4 ions (building blocks of tooth and bone mineral in a sustained manner while spontaneously converting to thermodynamically stable apatite. As a result of ACP’s bioactivity, local Ca- and PO4-enriched environments are created with supersaturation conditions favorable for the regeneration of tooth mineral lost to decay or wear. Besides its applicative purpose, our research also seeks to expand the fundamental knowledge base of structure-composition-property relationships existing in these complex systems and identify the mechanisms that govern filler/polymer and composite/tooth interfacial phenomena. In addition to an extensive physicochemical evaluation, we also assess the leachability of the unreacted monomers and in vitro cellular responses to these types of dental materials. The systematic physicochemical and cellular assessments presented in this study typically provide model materials suitable for further animal and/or clinical testing. In addition to their potential dental clinical value, these studies suggest the future development of calcium phosphate-based biomaterials based on composite materials derived from biodegradable polymers and ACP, and designed primarily for general bone tissue regeneration.

  6. Reformulating Polycaprolactone Fumarate to Eliminate Toxic Diethylene Glycol: Effects of Polymeric Branching and Autoclave Sterilization on Material Properties

    OpenAIRE

    Runge, M. Brett; Wang, Huan; Spinner, Robert J.; Windebank, Anthony J.; Yaszemski, Michael J.

    2011-01-01

    Polycaprolactone fumarate (PCLF) is a cross-linkable derivate of polycaprolactone diol that has been shown to be an effective nerve conduit material that supports regeneration across segmental nerve defects and has warranted future clinical trials. Degradation of the previously studied PCLF (PCLFDEG) releases toxic small molecules of diethylene glycol used as the initiator for the synthesis of polycaprolactone diol. In an effort to eliminate this toxic degradation product we present a strateg...

  7. 磷酸钙骨水泥/骨形态发生蛋白复合人工骨的生物相容性%Biocompatibility of calcium phosphate cement/BMP composite as bone graft material

    Institute of Scientific and Technical Information of China (English)

    孙明林; 胡蕴玉; 贾新斌; 李丹; 刘忠湘; 朱德生

    2001-01-01

    AIM To construct CPC/BMP composite by combining CPC with BMP, and to detect their biocompatibity. METHODS The toxicity, pyrogen, hemolytic activities and immunogen were detected by means of animal test, cell culture, hemolysis test and histochemical technique. RESULTS The composites were found no toxicity and no pyrogen by animal test, no hemolytic activities and couldn't influence the coagulate of blood in vitro. When the materials were grafted into the muscle pounches in the thigh of mice or rabbits, no obvious specific antibodies produced were detected in serum by ELISA, nor were significant immune reaction of foreign body observed by histochemistry technique. The composites were also testified no cytotoxicity in vitor for the proliferation of cultured cells couldn' be inhibited. CONCLUSION The CPC/BMP composite might have good biocompatibility and be safe for clinical use.%目的将自行合成的磷酸钙骨水泥(CPC)作为载体与BMP复合成人工骨,检测其生物相容性. 方法制备CPC/BMP及CPC骨块,通过体外实验、细胞培养、动物实验等方法观察其毒性、免疫原性、对血液系统的影响等生物相容性指标. 结果动物实验表明材料属无毒级,不含致热原,体外试验不引起溶血反应,对凝血功能无明显影响. 植入兔或小鼠肌袋内未检测出特异性抗体. 组织学检查未见免疫排斥反应,对肌肉无刺激作用.对体外培养的细胞增殖没有明显抑制作用.结论材料有较好的生物相容性,临床使用安全.

  8. Polymerization Initiated at the Sidewalls of Carbon Nanotubes

    Science.gov (United States)

    Tour, James M.; Hudson, Jared L.

    2011-01-01

    A process has been developed for growing polymer chains via anionic, cationic, or radical polymerization from the side walls of functionalized carbon nanotubes, which will facilitate greater dispersion in polymer matrices, and will greatly enhance reinforcement ability in polymeric material.

  9. The quantification of biocompatibility: toward a new definition

    Science.gov (United States)

    Ratner, Buddy

    2008-03-01

    Implantable medical devices, and the biomaterials that comprise them, form a 100B business worldwide. Medical devices save lives and/or improve the quality of life for millions. Tissue engineering also makes extensive use of biomaterials -- biomaterials are an enabling technology for tissue engineering. A central word to understanding the effectiveness of such materials and devices is biocompatibility. The word ``biocompatible'' is widely used in reference to biomaterials and medical devices and most everyone has some value understanding of its meaning. Many formal definitions have been proposed for this word, but it is still largely used in an imprecise manner. Four descriptions or definitions of biocompatibility will be reviewed: a widely adopted definition from a consensus conference, a surgeon's perspective on this word, the regulatory agency view and the factors that clearly influence biocompatibility. In this talk, the classical definition of biocompatibility will be contrasted to a newer definition embracing molecular concepts and the understanding of normal wound healing. The biological data on the in vivo healing responses of mammals to implants will be described. A strategy to improve the healing of biomaterials will be presented. It is based upon surface molecular engineering. First, non-specific protein adsorption must be inhibited. Strategies to achieve this design parameter will be presented. Then methods to deliver the specific protein signals will be addressed. Matricellular proteins such as osteopontin, thrombospondin 2 and SPARC will be introduced with an emphasis on exploiting the special reactivity of such proteins. A discussion of the influence of surface textures and porosities will also be presented. Finally a new scheme based upon macrophage phenotypic pathways will be proposed that may allow a quantitative measure of extent of biocompatibility.

  10. Nanocellulose for Biomedical Applications : Modification, Characterisation and Biocompatibility Studies

    OpenAIRE

    Hua, Kai

    2015-01-01

    In the past decade there has been increasing interest in exploring the use of nanocellulose in medicine. However, the influence of the physicochemical properties of nanocellulose on the material´s biocompatibility has not been fully investigated.  In this thesis, thin films of nanocellulose from wood (NFC) and from Cladophora algae (CC) were modified by the addition of charged groups on their surfaces and the influence of these modifications on the material´s physicochemical properties and on...

  11. Potential of polymeric materials for packaging; L'impiego dei materiali polimerici nell'imballaggio

    Energy Technology Data Exchange (ETDEWEB)

    Lanchi, M. [ENEA, Divisione Nuovi Materiali, Centro Ricerche Casaccia, Rome (Italy)

    2001-07-01

    Packaging preserves different kind of materials, from raw materials, and it plays an important role in the presentation of the products to the market, too. That's why packaging should be in charge of responding to marketing requirements by means of a proper design, effective colour choice and material, etc. Nowadays packaging is becoming more and more important in different fields. In Italy, it is a rapid growth of the packaging market and the companies involved are very competitive and efficient, in particular in some market segments. Concerning the application fields it can be asserted that packaging is mostly exploited in the food market which represents the 65% of the whole packaging market. Nearly all types of packaging use plastics as a part of their construction: lightness, chemical inertness, corrosion resistance, molding attitude, the good transparency to light, sound and mechanical insulation, etc. Focusing the attention to the horticultural market, growth in South of Italy in particular, examples of promising research fields to date are: developing of good barrier performance films; developing of suitable modified atmosphere packaging; developing of active plastic films, such as antimicrobic films or antioxidant films. The large amount of plastic films used for packaging create a large waste problem. This can be reduced by: optimising packaging design, avoiding the excessive use of plastics; improvising strength, moisture and heat stability per unit weight in order to reduce plastic waste volume; developing blend of plastics and bio-based polymer in order to increase the biodegradability of packaging after use. [Italian] L'imballaggio e' un prodotto adibito a contenere e a proteggere determinate merci, dalle materie prime ai prodotti finiti, a consentire la loro manipolazione e ad assicurare la loro presentazione. E' una realta' importante del mondo della produzione, delle strutture distributive e della vita quotidiana. Nell

  12. Biocompatibility of polytetrafluoroethylene combined with type I collagen as a nose filler material%聚四氟乙烯联合Ⅰ型胶原作为隆鼻高分子材料的生物相容性

    Institute of Scientific and Technical Information of China (English)

    尹中普; 孙晓

    2015-01-01

    BACKGROUND:Polytetrafluoroethylene (PTEE) as a nose filer material has advantages on the resistant to corrosion, chemical stability and so on. However, its linear expansion coefficient is large easily leading to infection and rejection, and its application has some limitations. OBJECTIVE:To compare the cel toxicity, inflammatory infiltrates and biocompatibility indexesin vivo between PTEE and PTEE combined with type Ⅰ colagen. METHODS: MTT method was used to detect the relative proliferation rate of L929 cels cultured with PTEE extract or PTEE combined with type Ⅰ colagen extract; an electron microscope was used to observe the cel growth. PTEE or PTEE combined with type Ⅰ colagen was embedded under the nasal dorsal fascia of New Zealand white rabbits for 7 days, and hematoxylin-eosin staining was used to detect whether nasal mucosa epithelial tissue had inflammatory infiltration. Systemic toxicity, alergies, pyrogen reaction and deaths of rabbits were observed after injection of two kinds of material extracts by ear vein. RESULTS AND CONCLUSION: The cytotoxicity and inflammatory infiltration were milder in PTEE combined with type Ⅰ colagen group than PTEE group (P < 0.05). The alergic reactions and pyrogen reactions were fewer in PTEE combined with type Ⅰ colagen group than PTEE group (P < 0.05). These findings indicate that PTEE combined with type Ⅰ colagen as the nose filer material has better biocompatibility.%背景:高分子材料聚四氟乙烯膨体作为隆鼻填充材料具有耐腐蚀、化学性质稳定等优点,但其线膨胀系数较大,易引发感染及排异反应,故应用有一定局限性.目的:对比聚四氟乙烯和聚四氟乙烯联合Ⅰ型胶原作为隆鼻填充材料的细胞毒性、埋植后的炎性浸润及体内生物相容性.方法:采用MTT法检测聚四氟乙烯浸提液和聚四氟乙烯联合Ⅰ型胶原浸提液培养L929细胞的细胞增殖.采用电子显微镜观察聚四氟乙烯浸提液和聚四氟乙

  13. Preparation of biocompatible molecularly imprinted shell on superparamagnetic iron oxide nanoparticles for selective depletion of bovine hemoglobin in biological sample.

    Science.gov (United States)

    Hao, Yi; Gao, Ruixia; Liu, Dechun; Zhang, Bianbian; Tang, Yuhai; Guo, Zengjun

    2016-05-15

    Bovine hemoglobin (BHb), as one of the high-abundance proteins, could seriously mask and hamper the analysis of low-abundance proteins in serum. To selectively deplete BHb, we design a simple and effective strategy for preparation of biocompatible molecularly imprinted shell on superparamagnetic iron oxide nanoparticles through surface imprinting technique combined with template immobilization strategy. Firstly, template proteins are immobilized on the directly aldehyde-functionalized magnetic nanoparticles through imine bonds. Then, with gelatin as functional monomer, a polymeric network molded around the immobilized template proteins is obtained. Finally, the specific cavities for BHb are fabricated after removing the template proteins. The effects of imprinting conditions were investigated and the optimal imprinting conditions are found to be 40mg of BHb, 150mg of gelatin, and 8h of polymerization time. The resultant materials exhibit good dispersion, high crystallinity, and satisfactory superparamagnetic property with a high saturation magnetization (33.43emug(-1)). The adsorption experiments show that the imprinted nanomaterials have high adsorption capacity of 93.1mgg(-1), fast equilibrium time of 35min, and satisfactory selectivity for target protein. Meanwhile, the obtained polymers could be used without obvious deterioration after six adsorption-desorption cycles. In addition, the resultant polymers are successfully applied in the selective isolation BHb from bovine blood sample, which could provide an alternative solution for the preparatory work of proteomics. PMID:26939073

  14. Study of anaerobic treatment in a system UASB of a rich industrial waste in polymeric organic material

    International Nuclear Information System (INIS)

    An agroindustrial company dedicated to the transformation of the waste, generated in the municipalities slaughterhouse, butcher shops and chicken farms such as: grease, bones, heads, feathers, skins, blood and other waste, that are used as principal ingredients for the production of bone flour, meat flour an grease. During this transformation residual waters are generated with a high demand chemical y biological have oxygenate, with a high concentration of proteins and grease. Those are dump in the creek in the city of the same name, with drastic consequences to the aquatic life and the generation of bad odours along the riverbank. For this reason a pilot studies took place in a reactor UASB with the purpose of establishing the conditions of operations and design of treatment plant. The high concentration of organic material of the residual waters (150 000 mg COD /L) makes it necessary the dilution of substrata. In helps to avoid the toxicity for NH3 for the characteristics of the substrata there is not necessary to add N.S.P (macro nutrients). During these studies various organic volumetric load were used (VOL) between 1.9 and 25 g COD/ day. The hydraulic retention time (HRT) between 6.5 and 25 hr. and the concentration of organic material in the influent of the reactor (Si) between 1500 and 7000 mg COD/L. obtaining the following results: the buffer capacity of the system permits to keep the ph between 6.7 -7.6. For a concentration of volatile fatty acids (VFA) higher then 12 meq/L and an index of alkalinity higher then 0.3 the system is unstable. It came to the conclusion that to keep stable conditions in the system the maxim VOL is 6 g COD/L day and the minimum HRT to obtain efficiencies of 79 % is 16 hr

  15. On-demand photoinitiated polymerization

    Science.gov (United States)

    Boydston, Andrew J; Grubbs, Robert H; Daeffler, Chris; Momcilovic, Nebojsa

    2013-12-10

    Compositions and methods for adjustable lenses are provided. In some embodiments, the lenses contain a lens matrix material, a masking compound, and a prepolymer. The lens matrix material provides structure to the lens. The masking compound is capable of blocking polymerization or crosslinking of the prepolymer, until photoisomerization of the compound is triggered, and the compound is converted from a first isomer to a second isomer having a different absorption profile. The prepolymer is a composition that can undergo a polymerization or crosslinking reaction upon photoinitiation to alter one or more of the properties of the lenses.

  16. Development of a polymeric matrix for composite material produced by the filament winding technique; Desenvolvimento de matriz polimerica visando a producao de material composito atraves da tecnica de enrolamento filamentar

    Energy Technology Data Exchange (ETDEWEB)

    Sobrinho, Ledjane Lima; Ferreira, Marisilvia; Bastian, Fernando Luiz [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    2005-07-01

    The study of the resin for composite materials to be produced by the filament winding technique is very important, since the good applicability of the technique is in part function of the characteristics of the resin. The objective of this work is the development of a polymeric matrix using vinyl ester resin for composite to be produced by the filament winding technique. Therefore, vinyl ester resin systems developed from Derakane 411-350 by varying the percentage of cure agent and activator. The system which presented the best behavior in tension (Yong's modulus 2,42 GPa, tensile strength = 47,67 MPa, elongation = 7,31 % and fracture toughness 2,67 J), adequate gel time and exothermic peak for the manufacture process was submitted to hygrothermal aging by immersion in water at 60 deg C for a maximum period of 64 days. (author)

  17. Biostability and biocompatibility of modified polyurethane elastomers

    Science.gov (United States)

    Christenson, Elizabeth Marie

    Several strategies have been employed to increase the biostability of medical grade polyurethanes while maintaining the desirable properties of current poly(ether urethanes). It was hypothesized that polyurethane surface chemistry controls biodegradation/biostability that can lead to ultimate failure/success of these materials in clinical applications. Chemical modification or replacement of the susceptible soft segment was evaluated as a design strategy to increase the biostability of medical grade polyurethanes. The effect of soft segment chemistry on the phase morphology, mechanical properties and in vivo response of commercial polyurethanes were compared. Poly(ether urethane) (PEU), silicone-modified poly(ether urethane) (PEU-S), poly(carbonate urethane) (PCU) and silicone-modified poly(carbonate urethane) (PCU-S) elastomers were investigated. AFM phase imaging indicated that the overall two-phase morphology of poly(ether urethanes), necessary for its thermoplastic elastomeric properties, was not disrupted by changing the soft segment chemistry. All of the polyurethanes exhibited thermoplastic elastomeric behavior similar to that of the poly(ether urethane). Following material characterization, the biocompatibility of the polyurethane elastomers was evaluated using a subcutaneous cage implant protocol. All of the polyurethanes tested retained the excellent biocompatibility typical of poly(ether urethane) elastomers. Overall, the candidate polyurethanes were concluded to be suitable replacements of current poly(ether urethane) elastomers in medical applications. The results from the cage implant study and cell culture experiments indicated that monocytes adhere, differentiate and fuse to form foreign body giant cells (FBGCs) on all of the polyurethane specimens. It is now generally accepted that the reactive oxygen species released by these adherent macrophages and FBGCs initiate PEU biodegradation. ATR-FTIR analysis of explanted samples provided evidence of

  18. Study of the sorption of nuclear fuel fission products using non-ion exchange polymeric and inorganic materials

    International Nuclear Information System (INIS)

    New tetrazamacrocycle and crown-ether poly-styrene and divinylbenzenepolystyrene derivatives (P-TAM and P-CE respectively) have been synthesized and studied as chemisorbents for Cs, Sr (P-CE) and Ru, Co (P-TAM) radioisotopes. It has been found that the tetraazamacro cycle modifier concentration in such material is about 5 x 10-4 M/g material. Model solutions, containing Ru and other platinoid salts, and also Co salts, were used in experiments at concentrations of 5 x 10-3 - 5 x 10-6 M/L. It was shown that P-TAM quantitatively removes Ru and other platinoids from the water solution at pH = 0-1 during 1-2 days and practically all modifying groups participate in the sorption process. It was established that in alkaline solutions this sorbent also adsorbs Co, Cr and other 3d-metal ions. P-TAM also demonstrates a very high platinoid sorption selectivity (close to 100%) from solutions containing, for example, platinoids in the presence of a large excess of 3d-metal ions. 137Cs sorption by some types of P-CE and IN-CE from Ringer-Locka model waste solution was also studied and it was found that Kd (Bq/g) strongly depends not only on the crown-ether ring size but also on the form in which crown-ethers exist on the surface, for example when the modifier was in the form of the complex such as P-CE-L(L=K3Fe(CN)6 or L=K4Fe(CN)6) there was an increase in K'd value (Bq/mole of CE). The results of a study of 85Sr removal by P-CE and IN-CE show that the chemisorption capacity strongly depends not only on the ''hole'' size of crown-ethers but also on the nature of encapsulated complexes, including ferrocyanides of different types. 32 refs, 5 figs, 5 tabs

  19. Ion implantation inhibits cell attachment to glassy polymeric carbon

    International Nuclear Information System (INIS)

    Implantation of MeV gold, oxygen, carbon ions into GPC alters the surface topography of GPC and enhances the already strong tendency for cells to attach to GPC. We have shown that implantation of silver ions near the surface strongly inhibits cell growth on GPC. Both enhanced adhesion of and inhibition of cell growth are desirable improvements on cardiac implants that have long been successfully fabricated from biocompatible glassy polymeric carbon (GPC). In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that ion beam assisted deposition (IBAD) of silver, as well as silver ion bombardment, can favorably influence the surface of GPC for biomedical applications

  20. Divinyl Sulfone Cross-Linked Cyclodextrin-Based Polymeric Materials: Synthesis and Applications as Sorbents and Encapsulating Agents

    Directory of Open Access Journals (Sweden)

    Julia Morales-Sanfrutos

    2015-02-01

    Full Text Available The aim of this study was to evaluate the crosslinking abilities of divinyl sulfone (DVS for the preparation of novel water-insoluble cyclodextrin-based polymers (CDPs capable of forming inclusion complexes with different guest molecules. Reaction of DVS with native α-cyclodextrin (α-CD, β-cyclodextrin (β-CD and/or starch generates a variety of homo- and hetero-CDPs with different degrees of crosslinking as a function of the reactants’ stoichiometric ratio. The novel materials were characterized by powder X-ray diffraction, electron microscopy and for their sorption of phenol and 4-nitrophenol. They were further evaluated as sorbents with phenolic pollutants (bisphenol A and β-naphthol and bioactive compounds (the hormone progesterone and curcumin. Data obtained from the inclusion experiments show that the degree of cross-linking has a minor influence on the yield of inclusion complex formation and highlight the important role of the CDs, supporting a sorption process based on the formation of inclusion complexes. In general, the inclusion processes are better described by a Freundlich isotherm although an important number of them can also be fitted to the Langmuir isotherm with R2 ≥ 0.9, suggesting a sorption onto a monolayer of homogeneous sites.