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Search results for: ANTIMICROBIAL POLYMER COATINGS
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Interfacially modified LDPE/GTR composites with non-polar elastomers: From microstructure to macro-behavior
PublicationThis paper provides some new insights into the mechanism of interaction and modifications in thermoplastic composites based on low density polyethylene (LDPE), ground tire rubber (GTR) and non-polar elastomer. The composites were prepared using a co-rotating twin-screw extruder at variable LDPE/GTR ratio and constant elastomer content. Two types of commercial elastomer were applied: styrene-butadiene-styrene (SBS) block copolymers (Kraton®)...
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Study of the effect of thermally reduced graphene oxide on the physical and mechanical properties of flexible polyurethane foams
PublicationFlexible polyurethane foams were obtained from a two-component system via the one-step method. The foams were modified with thermally reduced graphene oxide added in the amount equal to 0.25, 0.5 and 0.75 wt%. The morphology, static and dynamic properties, and thermal stability of modified foams were determined. The application of carbon filler resulted in the visible increase in the cell size, apparent density and rigidity of...
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Progress in non-isocyanate polyurethanes synthesized from cyclic carbonate intermediates and di- or polyamines in the context of structure–properties relationship and from an environmental point of view
PublicationCommercially, polyurethanes are produced by the reaction of diisocyanates, polyols (polyester or polyether) and low molecular weight chain extender. Toxicity, moisture sensitivity and phosgene-based synthesis of diisocyanates resulted in investigations focused on obtaining the non-isocyanate polyurethanes (NIPUs). This work presents the review of synthesis and structure–properties relationship of non-isocyanate polyurethanes obtained...
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FTIR spectroscopic and thermogravimetric characterization of ground tyre rubber devulcanized by microwave treatment
PublicationIn this work, the phenomena involved in the microwave devulcanization of ground tyre rubber (GTR) were investigated. Three types of GTR with different content of organic compounds (elastomers, plasticizers, etc.), carbon black and ash have been studied. The chemical structure of GTR before and after a microwave devulcanization process was analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)...
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Single-phase product obtained via crude glycerine depolymerisation of polyurethane elastomer: structure characterisation and rheological behaviour
PublicationPolyurethane recycling is a topic of growing interest due to the increasing amount of polyurethanewaste. The main purpose of polyurethane feedstock recycling is to recover the starting polyol, a valuable material. In thiswork, amethod of polyurethane thermo-chemical recycling, glycerolysisbymeansof crude glycerine, is proposed. Themaineffort is focusedonthe employment of crude glycerine without purification from biodiesel production...
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Modification of microporous polyurethane elastomers with different types of ash—morphological, mechanical, and thermal studies
PublicationIncorporation of wood ash particles from wood gasification into microporous polyurethane elastomers has been investigated and compared to addition of commercially available microspheres resulting from coal burning. Samples were modified with 3 and 6 wt% of fillers. Structure, mechanical, and thermal properties of obtained elastomers were investigated. Incorporation of both types of ash particles decreased the density of polyurethanes...
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An investigation on the role of GMA grafting degree on the efficiency of PET/PP-g-GMA reactive blending: morphology and mechanical properties
PublicationGlycidyl methacrylate (GMA) has been grafted on polypropylene (PP) with the aid of styrene (St) comonomer, by changing dicumyl peroxide initiator content, GMA level, and St concentration. The performance of the resulting PP-g-GMA reactive material towards static and dynamic mechanical properties of poly (ethylene terephthalate) (PET) was monitored in terms of grafting reaction variables and compatibilizer content. Fourier transform...
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Interrelationship between total volatile organic compounds emissions, structure and properties of natural rubber/polycaprolactone bio-blends cross-linked with peroxides
PublicationNatural rubber/polycaprolactone (NR/PCL) bio-based blends with different organic peroxides were prepared using an internal batch mixer and subsequently cross-linked at 170°C. Two types of commonly used organic peroxides, dicumyl peroxide and di(tert-butylperoxyisopropyl)benzene peroxide, were applied as free-radical initiator. Cross-linking efficiency of NR/PCL blends were investigated using oscillating disc rheometer measurements,...
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Assessment of the impact of bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes)
PublicationThe assessment of the impact of the bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes) Tecoflex® and Tecothane® is presented. The polyurethane samples were incubated with pure cultures of the microorganisms at 30 °C for five months. The changes in the chemical structure of the polymers were evaluated using loss of weight and contact angle...
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Tuning of microstructure in engineered poly (trimethylene terephthalate) based blends with nano inclusion as multifunctional additive
PublicationImmiscible blends and their composites are heterogeneous and have variable morphology due to variation in mesophase regions. Tuning, i.e. controlling the phase dimension is important, thereof we report a “super-combo” effect of multiwalled carbon nanotubes (MWCNTs) in poly (trimethylene terephthalate)/polypropylene (PTT/ PP) blend system. MWCNTs act as a good reinforcing agent and compatibilizer in the otherwise immiscible PTT/...
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Transport of paracetamol in swellable and relaxing polyurethane nanocomposite hydrogels
PublicationPolyurethane hydrogels are potentially attractive materials for biomedical applications. They are able to absorb large amount of water, biological fluids or active substances, and thus, they have potential to be used as absorbents or wound-healing dressings. They are also used for the controlled release of therapeutics because of their capacity to embed biologically active agents in their water-swollen network. The presence of...
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Physico‐Mechanical Properties and Flammability of PUR/PIR Foams Containing Expandable Graphite Core‐Shell Composite Particles
PublicationIn this work, polyurethane/polyisocyanurate (PUR/PIR) foams were modified by two types of expandable graphite (EG) core-shell composite particles. The pulverized EG core-shell composite particles were prepared during emulsion polymerization using methyl methacrylate or glycidyl methacrylate for the synthesis of the polymeric shells (poly(methyl methacrylate) (PMMA) and poly (glycidyl methacrylate) (PGMA)), and then the obtained EG_PMMA...
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Sustainable synthesis of cyclic carbonates from bio‐based polyether polyol: the structure characterization, rheological behaviour and thermal properties
PublicationThe cycloaddition of CO2 to epoxides represents a green efficient method to form bis(cyclic carbonate)s. The main purpose of the work reported in this paper was to examine the effect of the gas flow rate (20, 40, 60 and 100 mL min–1) during carbonation on the conversion yield, chemical structure, rheological behaviour and thermal properties of the prepared compounds. A series of new bis(cyclic carbonate)s was obtained from bio‐based...
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Rotational molding of polylactide (PLA) composites filled with copper slag as a waste filler from metallurgical industry
PublicationThe research work carried out so far indicates the ever wider possibilities and demand for shaping composite products in the rotational molding technology. This trend was the main reason to use waste-based filler from the metallurgical process as a filler for manufacturing polylactide (PLA)-based remolded composites. Copper slag (CS) was introduced in the single-step processing method to PLA matrix at 5, 10, 20, and 35 wt%. The...
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Biomechanical testing of bioactive bone cements – a comparison of the impact of modifiers: antibiotics and nanometals
PublicationApart from its bone filler and fracture stabilizing function, bone cement can be used as a carrier of bioactive substances, and such modified bone cement can protect the implant against microorganisms, treat local infections and combat bacteria introduced during the surgical procedure. In this paper, the effects of modifying antibiotics and nanosilver on the biomechanical properties of bone cement were examined. The following tests...
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The influence of different glycerine purities on chemical recycling process of polyurethane waste and resulting semi‐products
PublicationChemical recycling is the most favourable recycling method due to the possibility of polyol recovery. This work is dedicatedto the utilisation of crude glycerine and polyurethane waste. It aims at determining the impact of the use of glycerine fromthe production of biodiesel with various degrees of purity as a cleavage agent on the decomposition process of polyurethanefoam. The influence of glycerine purit y on the chemical structure...
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Structural, mechanical and thermal behavior assessments of PCL/PHB blends reactively compatibilized with organic peroxides
PublicationThe efficiency of two commercially available organic peroxides, dicumyl peroxide (DCP) and di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB), during reactive processing of poly (ε-caprolactone)/poly (3-hydroxybutyrate) (PCL/PHB) blends was investigated. The changes in chemical structure of PCL/PHB blends, as a function of organic peroxide type (DCP/BIB) and content (in range: 0–1.0 parts by weight - pbw), were characterized by Fourier...
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Evaluation and rationale of the performance of several elastomeric composites incorporating devulcanized EPDM
Publicationthylene Propylene Diene rubber (EPDM), is present in many applications. However, its crosslinked structure makes difficult its recycling. The use of devulcanized EPDM, (dEPDM) as a component of elastomeric composites, is a real possibility to reuse EPDM scraps. In this study, three matrices (natural rubber (NR), styrene butadiene rubber (SBR) and EPDM rubber) have been tested including devulcanized EPDM as a recycled component....
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Shape memory thin films of Polyurethane: Does graphene content affect the recovery behavior of Polyurethane nanocomposites?
PublicationThin nanocomposite films of polyurethane have received remarkable attention due to their shape memory properties. As most of the reports focus on the beneficial aspects of the presence of nanofillers such as graphene nanoplatelets (GNPs) introduced into shape memory polymers, some research results reveal the opposite trend. The polyether/polyester-based polyurethane was synthesized through a condensation polymerization and the...
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Fabrication of exfoliated graphite reinforced silicone rubber composites - Mechanical, tribological and dielectric properties
PublicationThe effect of exfoliated graphite (EG) on the mechanical, tribological and dielectric properties of the silicone rubber (QM) composites has been systematically investigated and analysed. Morphological analysis of the composites helps to understand the interfacial interaction between the filler and the rubber matrix as well as wear mechanism respectively. An enhancement in the mechanical, tribological and dielectric properties was...
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Fabrication of exfoliated graphite reinforced silicone rubber composites - Mechanical, tribological and dielectric properties
PublicationThe effect of exfoliated graphite (EG) on the mechanical, tribological and dielectric properties of the silicone rubber (QM) composites has been systematically investigated and analysed. Morphological analysis of the composites helps to understand the interfacial interaction between the filler and the rubber matrix as well as wear mechanism respectively. An enhancement in the mechanical, tribological and dielectric properties was...
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Synthesis, Characterization and Biological Investigations of Half-Sandwich Ruthenium(II) Complexes Containing Benzimidazole Moiety
PublicationHalf-sandwich Ru(II) complexes belong to group of biologically active metallo-compounds with promising antimicrobial and anticancer activity. Herein, we report the synthesis and characteri- zation of arene ruthenium complexes containing benzimidazole moiety, namely, [(η6-p-cymene)RuC l(bimCOO)] (1) and [(η6-p-cymene)RuCl2(bim)] (2) (where bimCOO = benzimidazole-2-carboxylate and bim = 1-H-benzimidazole). The compounds were characterized...
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High-performance method of carbon nanotubes modification by microwave plasma for thin composite films preparation
PublicationIn this work we present a simple and efficient method of nitrogen plasma modification of carbon nanotubes (CNTs). The process allows for treatment of the nanotubes in the form of powder with quite a high yield (65 mg of CNTs per hour). The modified carbon nanotubes contain approx. 3.8% of nitrogen, mostly in the pyridinic form. Plasma treated CNTs exhibit better dispersibility in water and higher electric capacitance than pristine...
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Essential oils as potential anti-staphylococcal agents
PublicationAntibiotic therapy of staphylococcal mastitis is characterized by significantly lower cure rates compared to infections caused by other microorganisms. Thus, it is necessary to search for new, alternative, non-antibiotic agents that are effective in the eradication of these bacteria. The aim of our research was to investigate the antimicrobial, especially anti-staphylococcal potential of a large collection (n=36) of essential oils...
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Structure and Molecular Dynamics in Renewable Polyamides from Dideoxy-Diamino Isohexide
PublicationThe chemical structure, the conformation, andthe flexibility of the polymer chain fragments present in thepolyamides synthesized from 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydrosorbitol, 1,4-diaminobutane, and either sebacic orbrassylic acid have been studied by liquid-state 2D NMRspectroscopy viz. correlation spectra (COSY) and heteronuclearmultiple-bond correlation spectra (gHMBC), by 13Ccross-polarization/magic-angle spinning...
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Investigation of poly(3,4-ethylenedioxythiophene) deposition method influence on properties of ion-selective electrodes based on bis(benzo-15-crown-5) derivatives
PublicationGlassy carbon electrodes modified by conductive polymers and membrane with derivatives of bis(benzo-15-crown-5) were tested as solid contact ion selective electrodes for K+ ions concentration determination. PEDOT with PSS, Cl- and ClO4- counter ions was electrochemically deposited onto glassy carbon substrates using four different electrochemical approaches (potentiostatic, galvanostatic, potentiodynamic and potentiostatic pulses)....
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Nanosize effect of clay mineral nanoparticles on the drug diffusion processes in polyurethane nanocomposite hydrogels
PublicationStudies of swelling and release of naproxen sodium (NAP) solution by polyurethane nanocomposite hydrogels containing Cloisite® 30B (organically modified montmorillonite (OMMT)) have been performed. Polyurethane nanocomposite hydrogels are hybrid, nontoxic biomaterials with unique swelling and release properties in comparison with unmodified hydrogels. These features enable to use nanocomposite hydrogels as a modern wound dressing....
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Towards azeotropic MeOH-MTBE separation using pervaporation chitosan-based deep eutectic solvent membranes
PublicationDeep eutectic solvents (DESs) are a new class of solvents that can offset some of the major drawbacks of common solvents and ionic liquids. When dealing with the preparation of dense membranes, the use of DESs is still challenging due to their low compatibility with the polymer phase. In this research, a novel L-proline:sulfolane (molar ratio 1:2) DES was synthesized and used for the preparation of more sustainable bio-based membranes...
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Remote Monitoring System for Impedance Spectroscopy using Wireless Sensor Network
PublicationThe architecture of a miniaturized impedanceanalyser with wireless communication module for remoteImpedance Spectroscopy (IS) of anticorrosion coatings ondifficult-to-reach objects (e.g. on the steel construction ofthe bridge) is described in this paper. Some practical aspectsof implementation of a Wireless Sensor Network (WSN) arealso discussed. A low scale, middle range, WSN networkcomposed of a Base Station (BS) with a Personal...
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Composite GFRP U-shaped footbridge
PublicationThe paper presents proposals for the use of glass fiber reinforced polymer composites for the construction of engineering objects, known and commonly used in the shipbuilding industry. An example of a pedestrian footbridge was used in this case, which, despite the considerable thickness of the structural material, was made using infusion technology in one production cycle. The designed and produced footbridge span is durable, dynamically...
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Application of the X-ray micro computed tomography to the analysis of the structure of polymeric materials
PublicationIn this paper the application of X-ray micro-computed tomography (micro-CT) as a non-destructive testing method of polymeric materials is presented. Increasing applicability of polymers in variedend-use industries such as automotive, building and construction, consumer goods, and packaging is propelling the growth of the global polymer processing market. However, controlling of the polymer structure is one of the most important...
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Assessment of Tensile Strength Reserve of Asphalt Mixtures at Low Temperatures
PublicationDuring winter conditions, low-temperature cracks develop at the surface of the asphalt pavement when tensile thermal stress induced in the asphalt layer during cooling equals and exceeds the tensile strength of the material. The paper presents the results of tensile strength reserve assessment of asphalt mixtures with neat and SBS-polymer modified bitumen application. The tensile strength reservewas calculated as difference between...
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RESEARCH ON HYDRODYNAMIC PEEK JOURNAL BEARINGS LUBRICATED WITH WATER AND OIL
PublicationThe main purpose of the research was to determine the possibilities and experimentally test the benefits of replacing conventional oil lubrication with ecological water lubrication. Tests were carried out on a test rig for hydrodynamic radial bearings under conditions representative of the expected applications for the bearing in water turbines. Bearings made from the polymer material PEEK (polyether ether ketone) were tested under static...
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Reviewing the recent developments of using graphene-based nanosized materials in membrane separations
PublicationAccording to the potentialities of graphene-based materials and their unique physicochemical properties. Such 2D nanomaterials are likely to be the most implemented within the improvement of the selective separations of polymer membranes, together with enhanced physicochemical properties (such as hydrophilicity/hydrophobicity, transport of molecules, mechanical and thermal features, among others). Hence, this review compiles and...
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Polyurethanes as a carrier of drugs for gentamicin
PublicationGentamicin is one of the most popular drug and is widely used due to its antibiotic properties. 3% of world production of polyurethanes (PU) is dedicated to biomedical applications, where they can serve are parts of orthopedic prosthesis or artificial organs, disposable medical devices, wound and burn dressing, contact lenses among others. In the study, to obtain drug carriers, a combination of these two materials were prepared...
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Problemy z powłokami antykorozyjnymi na elementach wyposażenia obiektów mostowych
PublicationPrzedstawiono problem wadliwości zabezpieczenia antykorozyjnego w zakresie malarskich powłok ochronno - dekoracyjnych wykonywanych na stalowych elementach barier zabezpieczonych uprzednio poprzez ocynkowanie metodą zanurzeniową. Wykorzystując przykłady pochodzące z różnych obiektów przedstawiono powtarzający się problem delaminacji powłok malarskich, niezależny od rodzaju zastosowanych wyrobów lakierniczych oraz znacznego rozwoju...
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Problemy z powłokami antykorozyjnymi na elementach wyposażenia obiektów mostowych
PublicationOpisano problem wadliwości zabezpieczenia antykorozyjnego w zakresie malarskich powłok ochronno-dekoracyjnych wykonywanych na stalowych elementach barier zabezpieczonych uprzednio poprzez ocynkowanie metodą zanurzeniową na gorąco. Wykorzystując przykłady pochodzące z różnych obiektów przedstawiono powtarzający się problem delaminacji powłok malarskich, niezależny od rodzaju zastosowanych wyrobów lakierniczych oraz znacznego rozwoju...
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Peptydy penetrujące – rodzaje i mechanizmy przenikania przez błony komórkowe
PublicationPeptydy penetrujące z pewnością są wyjątkową i ciekawą grupą związków peptydowych. Zostały odkryte ponad dwadzieścia lat temu, ale wiedza na ich temat wciąż jest rozbudowywana. Liczne badania nad mechanizmami ich przenikania do wnętrza komórek pozwalają zrozumieć jakie cechy strukturalne warunkują ich zdolność do penetracji komórek. Wiedza ta pozwala na projektowanie nowych, bardziej efektywnych peptydów penetrujących., które mogą...
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A Novel Cryptic Clostridial Peptide That Kills Bacteria by a Cell Membrane Permeabilization Mechanism
PublicationThis work reports detailed characteristics of the antimicrobial peptide Intestinalin (P30), which is derived from the LysC enzyme of Clostridium intestinale strain URNW. The peptide shows a broader antibacterial spectrum than the parental enzyme, showing potent antimicrobial activity against clinical strains of Gram-positive staphylococci and Gram-negative pathogens and causing between 3.04 ± 0.12 log kill for Pseudomonas aeruginosa...
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Biodegradable polymers for food packaging - factors influencing their degradation and certification types - a comprehensive review
PublicationIn the paper an overview of novel biodegradable polymers for food packaging can be found. The aim was to present factors influencing polymer degradation and biodegradation in various environments. It was noted that biodegradable polymers are imperfect alternative for classical polymers and its decomposition strongly depends on degradation environment.
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PREPARATION AND CHARACTERIZATION OF CoFe2O4/TiO2-PANI HYBRID NANOCOMPOSITE WITH MAGNETIC AND PHOYOCATALYTIC ACTIVITY
PublicationHybrid nanocomposites consisting of inorganic component and organic conducting polymer are promising materials, which can be applied in heterogeneous photocatalysis. Titanium(IV) oxide is widely used photocatalysts due to its non-toxicity, low cost and chemical stability. The main disadvantage of TiO2 is low photocatalytic activity under visible light. Conducting polymers, also known as conjugated polymers are polymer materials...
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Application of different modes of nanoscale impedance microscopy in materials research
PublicationIn recent years, there is noticeable interest in application of various types of scanning probe microscopy in material science research. One of them is contact atomic force microscopy combined with local impedance measurements, known as nanoscale impedance microscopy. Literature references present its application in investigations of new materials, microelectronics diagnostics, or research of protective coatings performance. In...
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Warstwy funkcjonalne tlenkowych ogniw paliwowych
PublicationIn this paper, results describing current research on solid oxide fuel cells conducted at Gdańsk University of Technology, Faculty of Electronics, Telecommunications and Informatics are presented. The results are related to three kinds of functional layers: a thin cathode layer between the porous cathode layer and the electrolyte to improve the cathode performance, a buffer layer between the electrolyte and the cathode to slow...
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Modelowanie losowych imperfekcji geometrycznych przestrzennych konstrukcji metalowych
PublicationImperfekcje geometryczne zbiorników, silosów i powłok siatkowych mogą znaczą-co wpłynąć na ich nośność, a więc powinny być one uwzględniane w obliczeniach komputerowych i w procesie projektowania. Wykazano, że przy podstawowych obcią-żeniach, działających na tego typu konstrukcje, tj. podciśnieniu oraz naporu wiatru i śniegu (w przypadku powłok siatkowych), wykazują wyraźne różnice w porównaniu z analogicznymi wynikami dla tych...
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Titania Nanofiber Scaffolds with Enhanced Biointegration Activity—Preliminary In Vitro Studies
PublicationThe increasing need for novel bone replacement materials has been driving numerous studies on modifying their surface to stimulate osteogenic cells expansion and to accelerate bone tissue regeneration. The goal of the presented study was to optimize the production of titania-based bioactive materials with high porosity and defined nanostructure, which supports the cell viability and growth. We have chosen to our experiments TiO2...
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iPP/HDPE blends compatibilized by a polyester: An unconventional concept to valuable products
PublicationPolyolefins are the most widely used plastics accounting for a large fraction of the polymer waste stream. Although reusing polyolefins seems to be a logical choice, their recycling level remains disappointingly low. This is mainly due to the lack of large-scale availability of efficient and inexpensive compatibilizers for mixed polyolefin waste, typically consisting of high-density polyethylene (HDPE) and isotactic polypropylene...
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Permeation and sorption properties of poly(ether-block-amide) membranesfilled by two types of zeolites
PublicationThe experimental study of transport properties of mixed matrix membranes (MMMs) based on PEBA-4033 with two types of zeolites is reported. Gas (CO2, O2, N2) and vapor (benzene, toluene, methanol, water) permeation measurements were performed using the differential flow permeameter at temperature of 298.15 K and at atmospheric pressure. Gas/vapor permeation was monitored by measuring the changes of the thermal conductivity of carrier...
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Dynamic tests of composite footbridge segment – experimental and numerical studies
PublicationExperimental dynamic tests and numerical simulations of a 3 meters long segment of a footbridge made of polymer composites are presented in the paper. The span-length is reduced, however dimensions of cross-section are the same as the target footbridge. The segment structure is made of sandwich panels, which consist of fibre reinforced polymer (GFRP) laminates (skins) and a PET foam (core). The first part of the paper contains...
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Functionalization of Parylene During Its Chemical Vapor Deposition
PublicationTwo possible mechanisms for the reaction of four halogenated (metha)acrylate-based molecules with Parylene [poly (paraxylylene)] during its chemical vapor deposition were proposed. The chemical reactivity of acrylate double bond with the paraxylylene biradical was calculated for all four (metha)acrylate-based molecules. These calculations allowed the evaluation of the energetically favorable mechanism and indeed a direct correlation...
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Core-Shell Nanoparticles with Hyperbranched Poly(arylene-oxindole) Interiors
PublicationCore-shell type star polymers composed of poly(tert-butyl acrylate) (poly(t-BuA)) arms and 100% hyperbranched poly(arylene-oxindole) interiors were synthesized via the "core-first" method. Atom transfer radical polymerization of t-BuA initiated by 2-bromopropionyl terminal groups of the hyperbranched core was applied for the synthesis of the stars. The resultant star structures were characterized by gel permeation chromatography...