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The structure of novel polyurethanes containing synthetic poly[(R,S)-3-hydroxybutyrate]
PublikacjaThe aim of this study was to estimate the structure of new polyurethanes with the potential to be used in medicine. Atactic poly[(R,S)-3-hydroxybutyrate], obtained via a ring-opening polymerization, and polycaprolactonediol or polyoxytetramethylenediol were used to built the soft segments. 4,4'-methylene dicyclohexyl diisocyanate and 1,4-butanediol were the components to form hard segments. Polyurethanes with low-molecular weight...
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Thermal and Mechanical Properties of Microporous Polyurethanes Modified with Reduced Graphene Oxide
PublikacjaMicroporous polyurethanes (MPU) were modified by adding 0.25%–1.25 wt% of reduced graphene oxide (RGO). The materials were prepared without solvent via in situ polymerization. From a technological point of view, it is very important to obtain functional materials by using reacting compounds only. The thermal characteristics of obtained MPU were investigated using TGA, DSC, and DMA techniques. In comparison to nonmodified microporous...
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Self-Organization of Graft Copolymers and Retortable iPP-Based Nanoporous Films Thereof
PublikacjaPolyolefins might become inexpensive alternatives to the existing membranes based on polyethersulfone. Here we disclose the production of retortable, well-defined PP-based nanoporous membranes derived from amphiphilic graft copolymer precursors. The graft copolymers, containing a polypropylene backbone and polyester grafts, were obtained by grafting lactones, specifically δ-valerolactone and ε-caprolactone, from well-defined randomly...
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Super tough interpenetrating polymeric network of styrene butadiene rubber‐poly (methyl methacrylate) incorporated with general purpose carbon black ( N660 )
PublikacjaA classic set of polymeric interpenetrating polymeric network (IPN) microcomposites has been fabricated using an elastomer—styrene butadiene rubber [SBR], a thermoplastic poly(methyl methacrylate)-PMMA and with carbon black (CB)-N660 as a filler and reinforcing agent. This synthesized IPN composite can be promisingly employed as a toughened plastic and vibrational damper in a wide service range with excellent thermal stability,...
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Crystallization kinetics study of dynamically vulcanized PA6/NBR/HNTs nanocomposites by nonisothermal differential scanning calorimetry
PublikacjaInvestigation of crystallization behavior and kinetics of thermoplastic elastomer nanocomposites was the subject of limited works because of complexities associated with semiexperimental modeling of such phenomenon in a system containing components having completely different behavior in the molten state. Nonisothermal crystallization kinetics of dynamically vulcanized PA6/NBR/HNTs thermoplastic elastomer nanocomposites was mathematically...
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Galvanostatic impedance measurements for the efficient adsorption isotherm construction in corrosion inhibitor studies
PublikacjaWe present an approach towards an accurate and time-efficient adsorption isotherm determination to evaluate the corrosion inhibitor interaction in electrolytic environments. The approach is based on dynamic impedance spectroscopy measurements in galvanostatic mode (g-DEIS). The studied corrosion inhibitor is continuously injected between the secondary cell and the corrosion cell. The efficiency corresponding to instantaneous inhibitor...
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Research on Linear Actuators for Active Foil Bearings
PublikacjaActive foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed...
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Bacterial nanocellulose as a microbiological derived nanomaterial
PublikacjaBacterial nanocellulose (BNC) is a nanofibrilar polymer produced by strains such as Gluconacetobacter xylinus, one of the best bacterial species which given the highest efficiency in cellulose production. Bacterial cellulose is a biomaterial having unique properties such as: chemical purity, good mechanical strength, high flexibility, high absorbency, possibility of forming any shape and size and many others. Such a large number...
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Electrochemically Induced Synthesis of Triphenylamine-based Polyhydrazones
PublikacjaTriphenylamine-based hydrazones were subjected to electropolymerization process that gave well conductive hydrazone based polymers. The first example of polyhydrazone formation during the electrochemical process was shown. The estimation of polymer structure was demonstrated using IR spectroelectrochemistry. The EPR spectroelectrochemistry allowed to explain why in some cases dimer couldn’t be formed. The results of electrochemical,...
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Helena Janik prof. dr hab. inż.
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OIL-ASSISTED THERMO-MECHANICAL RECLAMATION OF GROUND TIRE RUBBER
PublikacjaNowadays, it is crucial to seek for the methods of by-products and waste utilization, considering both environmental and economic factors. The example of waste material generated in the massive amounts, which requires the attention is ground tire rubber generated during recycling of post-consumer car tires. It can be applied as a filler into different polymer matrices, but to enhance its effectivity proper modifications should...
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Failure characterisation of sandwich beams using integrated acoustic emission and digital image correlation techniques
PublikacjaThe paper presents the experimental study of the failure behaviour of sandwich beams subjected to bending. The samples examined are sandwich beams made of polyethylene terephthalate foam core and glass fibre-reinforced polymer laminate face sheets. In a series of experiments, it has been proposed to integrate diagnostic techniques with acoustic emission and digital image correlation to accurately track the cracking process on the...
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Direct human contact with siloxanes (silicones): safety or risk. Part 1: characteristics of siloxanes (silicones
PublikacjaSiloxanes are commonly known as silicones. They belong to the organosiliconcompounds and are exclusively obtained by synthesis. Their chemical structuredetermines a range of physicochemical properties which were recognized as unique.Due to the susceptibility to chemical modifications, ability to create short, long orcomplex polymer particles, siloxanes found an application in many areas of human life.
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The porosity and morphology of PU foams prepared by solvent casting/salt leaching method with different solvents
PublikacjaIn this study, the polyurethane (PU) system based on poly(ethylene-butylene) adipate diol, 1,6-hexamethylene diisocyanate, 1,4-butanediol and ascorbic acid is used to prepare a foamed material. Polymer foams were created using solvent casting/salt-particle leaching (SC/PL) method. The influence of the PU concentration in different solutions [either in a DMF or in DMF with THF as a co-solvent] on the morphology and porosity of the...
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Synergistic effect of multi walled carbon nanotubes and reduced graphene oxides in natural rubber for sensing application
PublikacjaUtilizing the electrical properties of polymer nanocomposites is an important strategy to develop high performance solvent sensors. Here we report the synergistic effect of multi walled carbon nanotubes (MWCNTs) and reduced graphene oxide (RGO) in regulating the sensitivity of the naturally occurring elastomer, natural rubber (NR). Composites were fabricated by dispersing CNTs alone and together with exfoliated RGO sheets (thermally...
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Modal analysis of temporary steel grandstand equipped with different bracing systems
PublikacjaThe aim of this paper is to present the results of numerical analysis focused on temporary steel scaffolding grandstand. The investigation has been devoted to modal analysis where modes of free vibrations and corresponding natural frequencies have been estimated and compared. The structure was equipped with different types of stiffener members. One on them is a typical tubular stiffener, while the second one is spe-cially designed...
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Effects of Basalt and Carbon Fillers on Fire Hazard, Thermal, and Mechanical Properties of EPDM Rubber Composites
PublikacjaDue to growing restrictions on the use of halogenated flame retardant compounds, there is great research interest in the development of fillers that do not emit toxic compounds during thermal decomposition. Polymeric composite materials with reduced flammability are increasingly in demand. Here, we demonstrate that unmodified graphene and carbon nanotubes as well as basalt fibers or flakes can act as effective flame retardants...
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Investigation of sweet substances of different molecular structure by potentiometric taste sensor with all solid state electrodes
PublikacjaA five channel potentiometric taste sensor consisting of an array of All Solid State Electrodes (ASSESs) with different lipid-polymer membranes has been developed. The electrodes are constructed of glassy carbon discs with electrochemically deposited poly(3,4-ethylenedioxythiophene) (PEDOT) acting as ion to electron transducer. The outer layer of the electrode is lipid-polymer membrane. Lipid substances immobilized in PVC membranes...
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Superconductivity in Metal-Rich Chalcogenide Ta2Se
PublikacjaThe metal–metal bond in metal-rich chalcogenide is known to exhibit various structures and interesting physical properties. Ta2Se can be obtained by both arc-melting and solid-state pellet methods. Ta2Se crystallizes a layered tetragonal structure with space group P4/nmm (No. 129; Pearson symbol tP6). Each unit cell consists of four layers of body-centered close-packing Ta atoms sandwiched between two square nets of Se atoms, forming...
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Effects of CO2 and Nd:YAG Laser Remelting of the Ti6Al4V Alloy on the Surface Quality and Residual Stresses
PublikacjaThe titanium alloys are materials susceptible to tribological wear and the laser treatment can be applied in surface treatment processes to obtain for example higher hardness level. From the other side, it is important to take into consideration, that hardness increase that can be connected with cracks . The aim of this research was to investigate the effects of different lasers and the process parameters on the form and level...
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Mechanical Properties and Wear Susceptibility Determined by Nanoindentation Technique of Ti13Nb13Zr Titanium Alloy after “Direct Laser Writing”
PublikacjaLaser treatment has often been applied to rebuild the surface layer of titanium and its alloys destined for long-term implants. Such treatment has always been associated with forming melted and re-solidified thin surface layers. The process parameters of such laser treatment can be different, including the patterning of a surface by so-called direct writing. In this research, pulse laser treatment was performed on the Ti13Nb13Zr...
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Research of chitosan coatings deposited by electrophoretic deposition method at various voltage and time parameters
PublikacjaThe aim of this research is to estimate the electrophoretic deposition main parameters, such as voltage and time duration, that will provide optimal characteristics of the surface layer. Chitosan coatings were synthesized on biomedical Ti13Zr13Nb alloys at 20 V and 30 V and with deposit times of 2min, 5 min, 10 min, and 15 min. Evaluation of the coating was performed by using Scanning Electron Microscope (SEM), Energy-Dispersive...
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Oxidation and hydrogen behavior in Zr-2Mn alloy
PublikacjaThe purpose of the present research was to determine the oxidation and hydrogenation behavior in the new Zr-2Mn alloy. The oxidation of alloy was performed at temperatures between 350°C and 900°C for 30 minutes. The hydrogen charging was made for 72 h at a current density 80 mA/cm2. The charged samples were heat treated at 400°C for 4 h to obtain a uniform hydrogen profile content across the sample. The oxidation resulted in an...
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Entropy Production Associated with Aggregation into Granules in a Subdiffusive Environment
PublikacjaWe study the entropy production that is associated with the growing or shrinking of a small granule in, for instance, a colloidal suspension or in an aggregating polymer chain. A granule will fluctuate in size when the energy of binding is comparable to k_{B}T, which is the “quantum” of Brownian energy. Especially for polymers, the conformational energy landscape is often rough and has been commonly modeled as being self-similar...
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OBTAINING OF COUMARONE-INDENE RESINS BASED ON LIGHT FRACTION OF COAL TAR 3. COUMARONE-INDENE RESINS WITH METHACRYLIC FRAGMENTS
PublikacjaThe method for obtaining coumarone-indene resins with methacrylic fragments (CIRM) was developed with the addition of methyl ethacrylate, using a light fraction of coal tar and its fraction boiling within 423–463 К. CIRM was obtained via radical cooligomerization using 2,2'-azobis (2-methyl-propionitrile) as the initiator. The effect of the initiator amount, temperature and reaction time on the yield, softening temperature and...
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Rolling Resistance And Tire/Road Noise on Rubberized Asphalt Pavement In Poland
PublikacjaThe paper presents results of tire/road noise and rolling resistance measurements performed on stone-matrix asphalt (SMA) that contains rubberized asphalt developed and produced by the company in Poland. Bituminous binder was modified with polymer and additive of crumb rubber. First observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger car...
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Molecular dynamics studies of polyurethane nanocomposite hydrogels
PublikacjaPolyurethane PEO-based hydrogels have a broad range of biomedical applicability. They are attractive for drug-controlled delivery systems, surgical implants and wound healing dressings. In this study, a PEO based polyurethane hydrogels containing Cloisite R 30B, an organically modified clay mineral, was synthesized. Structure of nanocomposite hydrogels was determined using XRD technique. Its molecular dynamics was studied by means...
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KOMPOZYTOWY MOST PIESZO - ROWEROWY
PublikacjaPaper presents the composite foot and cycle bridge developed in FOBRIDGE grant cofinanced by The National Centre for Research and Development and realized by consortium of Gdansk University of Technology (leader), Military University of Technology in Warsaw and ROMA Sp. z o.o. in Toruń. The purpose of the grant was to design a shell type single span foot and cycle bridge made of composite materials, with the assumption of manufacturing...
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Rolling resistance and tyre/road noise on rubberised asphalt pavement in Poland
PublikacjaThe paper presents results of tyre/road noise and rolling resistance measurements performed on stone mastics asphalt (SMA) that contains rubberised asphalt, developed and produced by a refinery in Poland. Bituminous binder was modified with polymer and addition of crumb rubber. The first observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger...
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Usuwanie lotnych związków organicznych z fazy gazowej z zastosowaniem cieczy jonowych
PublikacjaUżycie cieczy jonowej do usuwania LZO jest limitowane przez rozpuszczalność usuwanych związków. Dane literaturowe sugerują, że ciecze jonowe jako faza membranowa mogą być z powodzeniem stosowane do selektywnej separacji węglowodorów aromatycznych z mieszanin węglowodorów aromatycznych i alifatycznych. Przedmiotem pracy było kompleksowe opisanie procesu separacji LZO z fazy gazowej z uwzględnieniem czynników wpływających na efektywność...
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Vascular stents - materials and manufacturing technologies
PublikacjaThe objective of this article is to present materials and technology for the manufacture of vascular stents with appropriate design requirements. The use of the right material is very important in implantology. A biomaterial introduced into the circulatory system must be biocompatible and hemocompatible. At the same time, it should not initiate toxic, mutagenic, or immunological reactions. Currently, 316L stainless steel (316L...
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EFFECT OF SURFACE STATE AND STRESS ON AN OXIDATION OF THE ZIRCALOY-2 ALLOY
PublikacjaZr alloys are widely used as materials for nuclear fuel pellets in the nuclear industry. In the case of the LOCA or RIA happen, a temperature may locally reach high values. Even if the high temperature maintains shortly, the zirconium oxides may become permeable, absorb hydrogen appearing in cooling water from decomposition reaction and crack because of formation and brittle failure of hydrides. Such model cannot so far take into...
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Design of a Shape-Memory-Alloy-Based Carangiform Robotic Fishtail with Improved Forward Thrust
PublikacjaShape memory alloys (SMAs) have become the most common choice for the development of mini- and micro-type soft bio-inspired robots due to their high power-to-weight ratio, ability to be installed and operated in limited space, silent and vibration-free operation, biocompatibility, and corrosion resistance properties. Moreover, SMA spring-type actuators are used for developing different continuum robots, exhibiting high degrees...
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X-Ray Computer Tomography Study of Degradation of the Zircaloy-2 Tubes Oxidized at High Temperatures
PublikacjaThe investigations of high-temperature oxidation of zirconium alloys, applied for fuel pellets in nuclear power plants, are usually limited to oxidation kinetics, phase transformations and microstructural characterization. The purpose of this research was to characterize the degradation phenomena occurring within oxide layer and at the interface oxide/metal, on internal and external Zircaloy-2 tube...
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Stability and phase transition investigation of olanzapine polymorphs
PublikacjaWe use electrical embedded-fragment QM method with both DFT/ωB97XD/6-31G* and MP2/6-31G* to investigate the phase transformations of olanzapine. Gibbs free energy calculations predict that form I is always the most stable structure and form II is the least stable one, while form IV is more stable than form III below about 200 K but less stable above this temperature, implying a polymorphic phase transformation. This may account...
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Gas sensors based on conducting polymers-recent developments
PublikacjaThis work discusses sensing performance dependence of PEDOT polymer and its composites on the counter ions used in the polymerization process. The sensors based on PEDOT-RGO composite show reversible response to NO2, while on PEDOT/LiClO4 irreversible. As a result, PEDOT-RGO could be used as a typical gas sensor, while sensor based PEDOT/LiClO4 could be used as an integrating gas sensor, also known as an accumulating gas sensor....
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Synthetic Principles Determining Local Organization of Copolyesters Prepared from Lactones and Macrolactones
PublikacjaA highly effective and facile technique for catalytic ring-opening copolymerization (cROP) of lactones viz. ε- caprolactone and ε-decalactone with ω-pentadecalactone is being described. The reactions were mediated by Zn- and Cabased tridentate Schiff base complexes and benzyl alcohol as initiator. The catalysts were successfully employed for the preparation of numerous block and random copolymers. To unravel the composition of...
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Three-point bending test of sandwich beams supporting the GFRP footbridge design process - validation
PublikacjaSome selected aspects concerning material and construction design issues for pedestrian footbridge made of GFRP composite materials are elaborated in this paper. The analysis is focused on validation tests, which are particularly important because of the advanced technology and materials that are used for this innovative bridge. The considered footbridge is a sandwich-type shell structure comprising of PET foam core and outer skins...
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Susceptibility to Degradation in Soil of Branched Polyesterurethane Blends with Polylactide and Starch
PublikacjaA very important method of reducing the amount of polymer waste in the environment is the introduction to the market of polymers susceptible to degradation under the influence of environmental factors. This paper presents the results of testing the susceptibility to degradation in soil of branched polyesterurethane (PUR) based on poly([R,S]-3-hydroxybutyrate) (R,S-PHB), modified with poly([D,L]-lactide) (PLA) and starch (St). Weight...
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Bioactivation of Konjac Glucomannan Films by Tannic Acid and Gluconolactone Addition
PublikacjaWound healing is a dynamic process that requires an optimal extracellular environment, as well as an accurate synchronization between various cell types. Over the past few years, great efforts have been devoted to developing novel approaches for treating and managing burn injuries, sepsis, and chronic or accidental skin injuries. Multifunctional smart-polymer-based dressings represent a promising approach to support natural healing...
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Agnieszka Susik
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Pervaporation Zeolite-Based Composite Membranes for Solvent Separations
PublikacjaThanks to their well-defined molecular sieving and stability, zeolites have been proposed in selective membrane separations, such as gas separation and pervaporation. For instance, the incorporation of zeolites into polymer phases to generate composite (or mixed matrix) membranes revealed important advances in pervaporation. Therefore, the goal of this review is to compile and elucidate the latest advances (over the last 2-3 years)...
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THE IMPACT OF GROUND TIRE RUBBER TREATMENT ON THE THERMAL CONDUCTIVITY OF FLEXIBLE POLYURETHANE/GROUND TIRE RUBBER COMPOSITES
PublikacjaWaste car tires are burdensome waste, and their utilization is crucial for the natural environment. In many countries, the primary method of their recycling is energy recovery, performed by simple combustion. However, material recycling is much more effective and significantly more beneficial for the natural environment. It results in the generation of ground tire rubber, which can be used to produce polymerrubber composites. It...
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The possibility of the application of a potentiometric sensor with all-solid-state electrodes for the quality control of different natural waters
PublikacjaThe quality of various natural waters was examined by a new potentiometric sensor with six all solid state electrodes containing an appropriate lipophilic compound in a polymer membrane. Physicochemical parameters such as conductivity and acidity of tested waters were also tested. All waters were neutral or slightly alkaline and contained different ions (e.g., Cl–) due to the place of their sampling (a coastal zone and a moraine...
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Capacitance Enhancement by Incorporation of Functionalised Carbon Nanotubes into Poly(3,4-Ethylenedioxythiophene)/Graphene Oxide Composites
PublikacjaThis paper reports on the role of oxidised carbon nanotubes (oxMWCNTs) present in poly-3,4-ethylenedioxytiophene (PEDOT)/graphene oxide (GOx) composite. The final ternary composites (pEDOT/GOx/oxMWCNTs) are synthesised by an electrodeposition process from the suspension-containing monomer, oxidised carbon nanotubes and graphene oxide. Dissociated functional groups on the surface of graphene oxide play a role of counter-ions for the...
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Nonlinear Viscoelastic Properties of Polyurethane Nanocomposites
PublikacjaIn recent years, the nonlinear viscoelastic behaviors of elastomeric nanocomposites have been examined, especially for a wide range of rubbery composite (including natural rubber) materials. This chapter describes the influence of fillers and nanofillers on the nonlinear viscoelastic properties of elastomeric polyurethane systems. These filled elastomers (similar to the classic natural rubber reinforced elastomers), also exhibit...
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Influence of electropolymerization conditions on the morphological and electrical properties of PEDOT film
PublikacjaIn this work the effects of electropolymerization conditions on the morphological properties and conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) film have been studied. PEDOT films were electrochemically synthesized in a one step process from acetonitrile solution containing 3,4-ethylenedioxythiophene (EDOT) and lithium perchlorate. Based on atomic force microscopy, scanning electron microscopy, cyclic voltammetry and...
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Catena-Poly[{[mu]-[eta]5:[eta]5-1-[2-(dimethylamino)ethyl-[kappa]N]cyclopentadienyl}-lithium(I)-([mu]-1,1,3,3-tetra-tert-butyltriphosphane-[kappa]3P2:P1,P3)lithium(I)]
PublikacjaThe title compound, [Li2(C9H14N)(C16H36P3)]n, is a by-product of the reaction of [Cp(C5H4CH2CH2NMe2)ZrCl2]n with tBu2P-P(SiMe3)Li in toluene. It is a coordination polymer composed of infinite chains running along [010]. One Li(I) atom is chelated by the cyclopentadienyl ring and and the N atom of the scorpionate ligand and a P atom, whereas the other Li(I) atom is coordinated by the backside of the cyclopentadienyl ring and two...
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Badania bioaktywności z wykorzystaniem komórek kościotwórczych na tytanie pokrytym chitozanem = Bioactivity studies using osteogenic cells on titanium coated with chitosan
PublikacjaChitosan is a natural polymer from the group of polysaccharides, which has found wide application in biomedical applications to induce bioactivity of implant. The studies described were carried out test imposition of chitosan membranes with varying degrees of deacetylation on the surface of titanium, and then check the bioactivity of the material in vitro, using osteogenic cells MC3T3-E1. Titanium surface before imposition of...
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Recurrent potential pulse technique for improvement of glucose sensing ability of 3D polypyrrole
PublikacjaIn this work, a new approach for using a 3D polypyrrole (PPy) conducting polymer as a sensing material for glucose detection is proposed. Polypyrrole is electrochemically polymerized on a platinum screen-printed electrode in an aqueous solution of lithium perchlorate and pyrrole. PPy exhibits a high electroactive surface area and high electrochemical stability, which results in it having excellent electrocatalytic properties. The...