Search results for: hydrogels
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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Hydrożele
PublicationOd wieków ludziom towarzyszyły trzy główne rodzaje materiałów: szkło, ceramika i metale. Wraz z rozwojem cywilizacji poszukuje się coraz to nowszych substancji, które wykazują cenne właściwości i pozwalają na szerokie zastosowanie. Jednym z takich przykładów są hydrożele, które często nazywane są superabsorbentami. Jak sama nazwa wskazuje są to żele zawierające wodę. Podstawowym elementem ich budowy jest polimer, czyli wielkocząsteczkowa...
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Hydrogels Based on Natural Polymers for Cardiac Applications
PublicationIn this work agar- and borax-based hydrogels with and without the addition of poly(vinyl alcohol) (PVA) at different concentrations were synthesized. Hydrogels were modified by the same amount of acetylsalicylic acid (ASA) which exhibits antithrombotic properties. The effect of modification by ASA on the properties of hydrogels was analyzed.
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Review: synthetic polymer hydrogels for biomedical applications
PublicationSynthetic polymer hydrogels constitute a group of biomaterials, used in numerous biomedical disciplines, and are still developing for new promising applications. The aim of this study is to review information about well known and the newest hydrogels, show the importance of water uptake and cross-linking type and classify them in accordance with their chemical structure.
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Molecular dynamics studies of polyurethane nanocomposite hydrogels
PublicationPolyurethane 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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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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Application of 3D- printed hydrogels in wound healing and regenerative medicine
PublicationHydrogels are three-dimensional polymer networks with hydrophilic properties. The modifiable properties of hydrogels and the structure resembling living tissue allow their versatile application. Therefore, increasing attention is focused on the use of hydrogels as bioinks for three-dimensional (3D) printing in tissue engineering. Bioprinting involves the fabrication of complex structures from several types of materials, cells,...
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Polysaccharide-based electroconductive hydrogels: Structure, properties and biomedical applications
PublicationArchitecting an appropriate platform for biomedical applications requires setting a balance between simplicity and complexity. Polysaccharides (PSAs) play essential roles in our life in food resources, structural materials, and energy storage capacitors. Moreover, the diversity and abundance of PSAs have made them an indispensable part of food ingredients and cosmetics. PSA-based hydrogels have been extensively reviewed in biomedical...
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UV-crosslinkable photoreactive self-adhesive hydrogels based on acrylics
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Recent Progress on Hydrogen Storage and Production Using Chemical Hydrogen Carriers
PublicationDepleting fossil fuel resources and anthropogenic climate changes are the reasons for the intensive development of new, sustainable technologies based on renewable energy sources. One of the most promising strategies is the utilization of hydrogen as an energy vector. However, the limiting issue for large-scale commercialization of hydrogen technologies is a safe, efficient, and economical method of gas storage. In industrial practice,...
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Conducting Polymer Microelectrodes Anchored to Hydrogel Films
PublicationArtykuł prezentuje wytwarzanie organicznych hydrożeli z mikroelektrodami poli(3,4-ethylenedioxythiophene, PEDOT), które wykazują obniżoną rezystywność 100 Ω/□. Proces przygotowania rozpoczyna się elektroosadzania przewodzącego PEDOT (ok. 20 S/cm) na mikroelektrodach Pt. Elektrolityczne wiąże się film PEDOT z hydrożelem. Tak wytworzona struktura jest odrywana elektrycznie pd podłoża.
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Naturally-derived hydrogels for 3D pancreatic tumor models: A short review
PublicationStatistics suggest a high proportion of mortality rate by pancreatic cancer, which is a solid tumor characterized by high heterogeneity and the presence of a complex extracellular matrix. The very low effectiveness of pancreatic cancer treatment roots in the high metastatic potential and drug resistance of this tumor. Therefore, the quest for efficient cellular models enabling precise mimicking in vivo conditions, and anticancer...
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Precipitation of calcium carbonate in the presence of rhamnolipids in alginate hydrogels as a model of biomineralization
PublicationThis paper reports the effects of rhamnolipids presence in the alginate hydrogel and CO32- solution, on the precipitation of CaCO3 in the Ca2+ loaded alginate hydrogel. Characteristics of the formed particles are discussed. Model conditions containing alginate hydrogel and rhamnolipids were used in order to mimic the natural environment of biomineralization in biofilms. It has been shown that rhamnolipids affect the characteristics...
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Green and sustainable hydrogels based on quaternized chitosan to enhance wound healing
PublicationHydrogel-based biomaterials applied as wound dressings provide the wound with a moist environment, which facilitates tissue regeneration through granulation and re-epithelialization. The inherent flexibility and adjustable architecture of hydrogels enables incorporation of cells, antimicrobial drugs, growth factors, and bioactive compounds, which leads to expediting wound contraction and enhancing the regeneration process. The...
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The influence of chitosan hydrogels on the morphology of L929 cells
Open Research DataRepresentative image at 20x magnification of L929 cells following 24 h of treatment with chitosan derivatives: chitosan dissolved in carbonic acid, chitosan dissolved in carbonic acid endotoxin free, chitosan dissolved in hydroacetic acid at 1:3 diluent factor. The scale bar is 100 µm; Microscope Olympus IX83, Tokyo, Japan).
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Cytotoxicity of chitosan hydrogels aginst L929 cells
Open Research DataThis study presents absorbance values of formazan product (converted from MTT) which corresponds to the cytotoxicity of chitosan compounds (dissolved in carbonic acid, dissolved in carbonic acid endotoxin free, and dissolved in hydroxyacetic acid) aginst adult mouse fibroblast L929 cells. The experiments were carried out according to the ISO 10993-5:2009(E)...
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Influence of hydrogen on a nanocrystalline high-entropy oxide with application potential in hydrogen technologies
PublicationThe influence of hydrogen on a (Co0⋅2Cu0⋅2Mg0⋅2Ni0⋅2Zn0.2)O HEO with a rock salt structure was studied. Two forms of this HEO (nanopowder and sinter) were prepared via mechanochemical synthesis (MS) and additional heat treatment, respectively. The chemical stability of the synthesized samples in a pure hydrogen atmosphere was investigated using Sievert’s technique. High-pressure hydrogenation at 250 ◦C had no noticeable effect...
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Experimental and numerical study on spontaneous ignition of hydrogen and hydrogen-methane jets in air
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Injectable poloxamer/graphene oxide hydrogels with well‐controlled mechanical and rheological properties
PublicationAlthough significant progress has been made in the design and application of injectable hydrogels for biomedical applications, concurrent control of rheological and mechanical properties of injectable hydrogels has remained as an open challenge to the researchers. In this work, we introduce and put into practice a photo‐curable poloxamer (also known as Pluronic)/graphene oxide (Plu/GO) injectable hydrogel with well‐controlled rheological...
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Comprehensive study on graphene hydrogels and aerogels synthesis and their ability of gold nanoparticles adsorption
PublicationGraphene hydrogels were prepared by ascorbic acid-assisted gelation of graphene oxide (GO) aqueous suspensions both in acidic and basic conditions. Different mass ratio of ascorbic acid (AA) to GO was used (namely 20:1 and 10:1). In order to eliminate the influence of AA on the final structure of hydrogels, samples without AA were prepared by a hydrothermal gelation of GO in an autoclave. An in-depth structural characterization...
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Determination of Changes in Viscosity of Hydrogel Depending on Shear Rates
PublicationThe datasets entitled Determination of changes in viscosity of hydrogel depending on shear rate contain the results of viscosity measurements using a Brookfield viscometer, with different kinds of spindles and shear rates. The data allowed the used hydrogel preparations to be characterised and their functional parameters, as substances modifying the rheology of thickeners and determining the effect of shear rate on the viscosity...
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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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Influence of conductive carbon and MnCo2O4 on morphological and electrical properties of hydrogels for electrochemical energy conversion
PublicationIn this work, a strategy for one-stage synthesis of polymer composites based on PNIPAAm hydrogel was presented. Both conductive particles in the form of conductive carbon black (cCB) and MnCo2O4 (MCO) spinel particles were suspended in the three-dimensional structure of the hydrogel. The MCO particles in the resulting hydrogel composite acted as an electrocatalyst in the oxygen evolution reaction. Morphological studies confirmed...
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Hydrogen migration in photodissociation of the pyridine molecules
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Dietary antioxidants as a source of hydrogen peroxide
PublicationStudies of 54 antioxidants revealed that 27 of them, mainly polyphenols, generated hydrogen peroxide (H2O2) when added to Dulbecco’s modified Eagle’s medium (DMEM), other media used for culture of mammalian and yeast cells and phosphate-buffered saline. The most active antioxidants were: propyl gallate (PG), (−)-epigallocatechin gallate (EGCG) and quercetin (Q). Chelex treatment and iron chelators decreased H2O2 generation suggesting...
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Hydrogen generation using solar energy
PublicationWodór jest uważany za alternatywne i odnawialne źródło energii. Bezpośrednie wykorzystanie światła słonecznego do fotokatalitycznego lub fotoelektrochemicznego rozkładu wody może zapewnić w przyszłości ekonomicznie uzasadnione, alternatywne źródło wodoru. W pierwszym etapie naszych badań został zaprojektowany i zbudowany hybrydowy, fotowoltaiczno-elektrochemiczny układ, dokonujący konwersji energii promieniowania słonecznego na...
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Hydrogen generation using solar energy
PublicationWodór jest uważany za alternatywne i odnawialne źródło energii. Bezpośrednie wykorzystanie światła słonecznego do fotokatalitycznego lub fotoelektrochemicznego rozkładu wody może zapewnić w przyszłości ekonomicznie uzasadnione, alternatywne źródło wodoru. W wystąpieniu przedstawione zostały wyniki dotychczasowych prac związanych z hybrydową, fotowoltaiczno-elektrochemiczną instalacją do rozkładu wody oraz omówione zostały kierunki...
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Hydrogen sulphide electrocatalytic gas sensor
PublicationIn this article measurement results of the electrocatalytic gas sensor in different concentrations of hydrogen sulphide are presented. Working principle of such sensor is based on electric current acquisition, while voltage ramp is applied to the sensor. During voltage sweep oxidation and reduction reactions occurs on the sensor electrodes. Obtained current-voltage plot has unique shape connected...
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Methods for the characterizing hydrogen degradation of materials
PublicationDokonano przeglądu różnych metod szacowania podatności na niszczenie wodorowe materiałów metalowych. Zaprezentowano charakterystyki warunków środowiskowych: standardowe składy środowisk ciekłych i gazowych, temperatury, warunki polaryzacji elektrochemicznej. Omówiono metody mechaniczne szacowania niszczenia wodorowego różniące się stanem naprężeń, w tym badania: przy stałym obciążeniu, stałym odkształceniu i stałej niskiej szybkości...
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The effect of changes in the concentration of hydroxypropylcellulose on the rheological stability of pectin hydrogels.
Open Research DataThe rheological characteristics of the pectin hydrogel modified by hydroxypropylcellulose (added in a concetration range from 0.1 to 0.55% m/m) were made on the basis of the viscosity assessment using a Brookfield viscometer with an LV SC4 - 25 spindle and a shear rate of 0,22 s-1 in the temperature range 19-96 ° C.The data allowed selection of optimal...
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The impedance of hydrogen oxidation reaction in a proton exchange membrane fuel cell in the presence of carbon monoxide in hydrogen stream
PublicationEvaluation of performance of a proton exchange membrane fuel cell, which is affected by carbon monoxide that pollutes the hydrogen stream, was presented. This influence was studied for carbon monoxide concentration of 125–325 ppb, which are close to values specified in ISO 14687:2019 standard. Performed studies provided crucial information for further development of fuel cell as an energy source for automotive application. Impedance...
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Changes in the Mechanical Properties of Alginate-Gelatin Hydrogels with the Addition of Pygeum africanum with Potential Application in Urology
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Collagen and hyaluronic acid hydrogel in water-in-oil microemulsion delivery systems
PublicationThe efficacy of microemul-sion in dermal and transdermal delivery of active ingredients. Here, we assessed the water-in-oilmicroemulsion capacity to incorporate two natural polymers, i.e. collagen and hyaluronic acid withlow and high molecular weight. Systems were extensively characterized in terms of conductivity, phaseinversion studies, droplet diameter, polydispersity index and rheological properties. The results of thisresearch...
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LES–CMC study of an excited hydrogen flame
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Oxidation and hydrogen behavior in Zr-2Mn alloy
PublicationThe 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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The influence of process parameters on photocatalytic hydrogen production
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An experimental study of high-hydrogen welding processes
PublicationThis paper presents investigation results of determination of the diffusible hydrogen content in deposited metal obtained by means of two most often used methods-the glycerin method and the mercury method. Relation has been defined between results of those methods in the area characteristic of low-hydrogen as well as high-hydrogen welding processes. Relations available in the literature do not include the diffusible hydrogen content...
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Molecular hydrogen solvated in water – A computational study
PublicationThe aqueous hydrogen molecule is studied with molecular dynamics simulations at ambient temperature and pressure conditions, using a newly developed flexible and polarizable H2 molecule model. The design and implementation of this model, compatible with an existing flexible and polarizable force field for water, is presented in detail. The structure of the hydration layer suggests that first-shell water molecules accommodate the...
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Optimization of Hydrogen - Evolving Photochemical Molecular Devices
PublicationA molecular photocatalyst consisting of a RuII photocenter, a tetrapyridophenazine bridging ligand, and a PtX2 (X=Cl or I) moiety as the catalytic center functions as a stable system for light-driven hydrogen production. The catalytic activity of this photochemical molecular device (PMD) is significantly enhanced by exchanging the terminal chlorides at the Pt center for iodide ligands. Ultrafast transient absorption spectroscopy...
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Hydrogen degradation of pre-oxidized zirconium alloys
PublicationThe presence of the oxide layers on Zr alloys may retard or enhance the hydrogen entry and material degradation, depending on the layer features. This research has been aimed to determine the effects of pre-oxidation of the Zircaloy-2 alloy at a different temperature on hydrogen degradation. The specimens were oxidised in laboratory air at 350°C, 700°C, and 900°C. After, some samples were tensed at 10-5 strain rate and simultaneously...
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Hydrogen Damage in Superaustenitic 904L Stainless Steels
Publicationresults on the influence of hydrogen on corrosion resistance and of hydrogen embrittlement of 904L superaustenitic stainless steel were investigated. The cracking behavior was studied by performing a slow strain rate test in synthetic seawater under varying cathodic polarization conditions. The results showed that the steel’s plasticity varied with the applied cathodic current density. Significant reductions in ductility were found,...
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Hydrogen degradation of high strength weldable steels
PublicationW pracy przedstawiono wyniki badań podatności stali spawalnych o wysokiej wytrzymałości na niszczenie wodorowe. Badano dwa gatunki stali S690Q i ich złącza spawane. Ocenę podatności na niszczenie wodorowe wykonano w oparciu o próbę rozciągania z małą prędkością odkształcania w powietrzu i środowisku wody morskiej przy polaryzacji katodowej. Przedstawiono model niszczenia wodorowego badanych stali i ich złączy spawanych.
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Study on hydrogen uptake of functionalized carbon nanotubes
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Hydrogen degradation of high strength weldable steels
PublicationW pracy przedstawiono wyniki badań podatności stali spawalnych o wysokiej wytrzymałości na niszczenie wodorowe. Badano dwa gatunki stali S690Q i ich złącza spawane. Ocenę podatności na niszczenie wodorowe wykonano przy różnych rodzajach obciążeń w środowisku wody morskej przy polaryzacji katodowej.
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Multigap superconducting state in molecular metallic hydrogen
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Method for detection of hydrogen peroxide in HT22 cells
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9-Cyano-10-methylacridinium hydrogen dinitrate
PublicationThe title compound, C15H11N2+·HN2O6−, crystallizes in the monoclinic space group C2/c with four molecules in the unit cell. The planar 9-cyano-10-methylacridinium cations lie on crystallographic twofold axes and are arranged in layers, almost perpendicular to the ac plane, in such a way that neighbouring molecules are positioned in a `head-to-tail' manner. These cations and the hydrogen dinitrate anions are linked through C—H⋯O...
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Hydrogen charging of nitrided steel in acid solution
PublicationKonstrukcyjną stal, azotowaną w wyładowaniu jarzeniowym w mieszaninie gazów o różnej zawartości N2, H2 i Ar, poddawano katodowemu nawodorowaniu w kwaśnym roztworze, imitującym przepracowany olej maszynowy. W pomiarach szybkości przenikania wodoru i ekstrakcji próżniowej określano wpływ azotowanych warstw, odpowiednio, na transport wodoru i na jego nieodwracalne pułapkowanie. W obecności niezdefektowanej warstwy kompaktowych azotków...
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Influence of rhamnolipids and ionic cross-linking conditions on the mechanical properties of alginate hydrogels as a model bacterial biofilm
PublicationThe literature indicates the existence of a relationship between rhamnolipids and bacterial biofilm, as well as the ability of selected bacteria to produce rhamnolipids and alginate. However, the influence of biosurfactant molecules on the mechanical properties of biofilms are still not fully understood. The aim of this research is to determine the effect of rhamnolipids concentration, CaCl2 concentration, and ionic cross-linking...
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Graphene hydrogels with embedded metal nanopatricles as efficient catalysts in 4-nitrophenol reduction and methylene blue decolorization
PublicationSynthesis and characterization of the graphene hydrogels with three different metallic nanoparticles, that is Au, Ag and Cu, respectively is presented. Synthesized in a one-pot approach graphene hydrogels with embedded metallic nanoparticles were tested as heterogeneous catalysts in a model reaction of 4-nitrophenol reduction. The highest activity was obtained for graphene hydrogel with Cu NPs and additional reaction of methylene...