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Search results for: electrochemical immunosensor
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Detection of random transients caused by pitting corrosion
PublicationProces korozyjny może być badany za pomocą techniki szumu elektrochemicznego. Szum obserwowany jest jako fluktuacje prądowe i napięciowe w trójelektrodowym układzie pomiarowym. W celu stwierdzenia obecności korozji wżerowej wykonana została detekcja charakterystycznych sygnałów. Opracowany został algorytm oparty na analizie lokalnych zmian w spektrogramie rejestru prądowego. Spektrogram uzyskany został za pomocą krótkoczasowej...
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Instantaneous impedance monitoring of synergistic effect between cavitation erosion and corrosion processes
PublicationThe most common method of determination of cavitation erosion resistance as well as the magnitude of erosion-corrosion synergistic interaction is based on the weight loss measurements. Nondestructive characterization of installations elements is in most cases impossible to perform. Also, such a measurement does not include local types of failure or alteration of operating conditions. There is an urge to elaborate a method for monitoring...
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THE ROLE OF THIN FUNCTIONAL LAYERS IN SOLID OXIDE FUEL CELLS
PublicationWidespread commercialization of solid oxide fuel cells requires lowering its cost. It is generally accepted that to lower the cost of solid oxide fuel cells it is necessary to use metal alloys as interconnectors and, consequently, lower its operating temperature to slow down interconnectors degradation. As a result the area specific resistance of the cathodes should be lowered to sustain the performance of the cells. In order to...
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Impedance analysis of Portevin-Le Chatelier effect on aluminium alloy
PublicationW niniejszej pracy przeprowadzono badania elektrochemiczne powierzchniowego efektu PLC, związanego z nierównomiernym procesem płynięcia plastycznego stopów aluminium zawierających magnez. Występujący efekt PLC w postaci serration wywołuje niehomogeniczny proces zmian zewnętrznej powierzchni rozciąganej próbki. Wykonano badania metodą Dynamicznej Spektroskopii Impedancyjnej w warunkach dynamicznych prowadzenia procesu rozciągania....
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A facile preparation method and proof of cycle-stability of carbon-coated metal oxide and disulfide battery materials
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Spectroscopic and microscopic study of Prussian blue film for electrochromic device application
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Hierarchical porous carbon materials from nanosized metal-organic complex for high-performance symmetrical supercapacitor
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Low-cost nitrogen-doped activated carbon prepared by polyethylenimine (PEI) with a convenient method for supercapacitor application
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Phosphorus, nitrogen and oxygen co-doped polymer-based core-shell carbon sphere for high-performance hybrid supercapacitors
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Red phosphorus as self-template to hierarchical nanoporous nickel phosphides toward enhanced electrocatalytic activity for oxygen evolution reaction
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Toward elucidation of delithiation mechanism of zinc-substituted LiFePO4
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DEIS evaluation of the relative effective surface area of AISI 304 stainless steel dissolution process in conditions of intergranulatar corrosion
PublicationWyniki przedstawione w tej pracy stanowią dalszą część badań dotyczących procesu roztwarzania wysokostopowej stali AISI 304 w warunkach zachodzenia korozji międzykrystalicznej z wykorzystaniem techniki dynamicznej elektrochemicznej spektroskopii impedancyjnej (DEIS). Po raz pierwszy zaprezentowano zmiany względnej powierzchni efektywnej procesu roztwarzania stali AISI 304 w warunkach zachodzenia korozji międzykrystalicznej w funkcji...
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Assessment of organic coating degradation via local impedance imaging
PublicationThe paper presents a new approach to organic coating condition evaluation at micrometer scale using localized impedance measurements. It is based on atomic force microscopy (AFM) in contact mode. Impedance is measured between conductive AFM tip and metal substrate covered with organic coating. A single-frequency voltage perturbation signal is applied between the electrodes and current response signal is registered. As the tip is...
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Preparation and characterisation of visible light responsive iodine doped TiO2 electrodes
PublicationPraca przedstawia charakterystykę domieszkowanego jodem ditlenku tytanu (I-TiO2) otrzymanego na drodze hydrotermicznej syntezy, gdzie prekursor stanowiły komplesy tytanu (IV) z ligandami zawierającymi atom jodu. Struktura nowego materiału została opisana za pomocą technik XPS, XRD, UV-vis i FT-IR-ATR. Badania te potwierdziły, że otrzymany proszek I-TiO2 ma zmniejszoną przerwę energetyczną. Praca prezentuje również badania elektrochemiczne...
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Spectroelectrochemical characterization of euhedral anatase TiO2 crystals – Implications for photoelectrochemical and photocatalytic properties of {001} {100} and {101} facets
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Ni-MOF-based electrodes: A promising strategy for efficient overall water splitting
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Ultrafast self-expanded reduced graphene oxide and 2D MoS2 based films as anode in Li-ion battery
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Electroactive heterojunctions of iron-based compounds in oxygen evolution reaction—Insight into synergy and mechanism
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Atomic force microscopy based approach to local impedance measurements of grain interiors and grain boundaries of sensitized AISI 304 stanless steel
PublicationPraca prezentuje wyniki badań uzyskane z pomiarów techniką lokalnej spektroskopii impedancyjnej (LIS) wykonanych w trybie kontaktowym mikroskopii sił atomowych (AFM), które zostały przeprowadzone w lokalnych obszarach powierzchni ziarna austenitu i na granicy ziarna austenitu wysokostopowej stali austenitycznej AISI 304 poddanej procesowi uczulania oraz na próbkach odniesienia nie poddanych obróbce cieplnej.Badania LIS-AFM były...
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Mesoscopic impedance analysis of solid materials surface
PublicationSeveral techniques have been developed in order to characterize electrical properties of surfaces in micrometer/nanometer scale. Obtaining of the spatial distribution of sample resistance, capacitance or potential requires separate measurements performed in different scanning modes. On the other hand, analysis of the frequency response of investigated system enables determination of several physical quantities in single measurement...
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Organic-inorganic composites consisted of poly(3,4-ethylenedioxythiophene)and Prussian Blue analogues
PublicationThe organic-inorganic material consisted of poly(3,4-ethylenedioxythiophene) (pEDOT) and copper hexacyanoferrate (Cuhcf) was synthesized. The pEDOT film with Fe(CN)63−/4− as counter-ions potentiodynamically polarized in aqueous CuCl2 electrolyte brings about stable hybrid material (pEDOT/Cuhcf) performing single redox activity of FeII/III at a formal potential Ef = 0.61 V (vs. Ag/AgCl/0.1 M KCl) and less clearly shaped two redox...
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Evaluation of citric acid corrosion inhibition efficiency and passivation kinetics for aluminium alloys in alkaline media by means of dynamic impedance monitoring
PublicationA novel approach is proposed for constructing the adsorption isotherm in corrosion studies, based on a well-known interaction between citric acid and aluminium in alkaline electrolytes. Our approach utilizes the instantaneous impedance measurements via Dynamic Electrochemical Impedance Spectroscopy in galvanostatic mode (g-DEIS). Unlike other common tools, g-DEIS delivers exact information about the concentration required for full...
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Sinusoidal Alternating-Current Voltammetry and Metrological Properties of a Flat Voltammetric Electrode in the Time Domain
PublicationIn this paper there were analyzed metrological properties of a flat electrode used to mark ions with the method of sinusoidal alternating-current voltammetry in the situation where on its surface an electrochemical reversible reaction of oxidizing / reduction takes place. The result of the analysis conducted is that such a voltammetric electrode functions like a converter type I. Metrological properties of such an electrode in...
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Determination of pitting corrosion stage of stainless steel by galvanodynamic impedance spectroscopy
PublicationThis paper investigates the methodology for differentiation of multistep process of pitting corrosion of AISI 304 stainless steel in the environment of iron (III) chloride. Measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Application of this methodology allowed monitoring of natural corrosion process without external current (IDC = 0A) nor potential perturbation of the system. Applied...
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The influence of polarization of titania nanotubes modified by a hybrid system made of a conducting polymer PEDOT and Prussian Blue redox network on the Raman spectroscopy response and photoelectrochemical properties
PublicationIn this work we show the impact of applied potential on network vibrations and photoelectrochemical properties of a composite material containing hydrogenated titania nanotubes and poly (3,4-ethylenedioxythiophene) with iron hexacyanoferrate (H-TiO2/pEDOT:Fehcf) acting as a redox centre. For this purpose, Raman spectroscopy measurements under the working electrode (WE) polarization were carried out, allowing investigation of changes...
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Cathodically activated Au/TiO2 nanocomposite synthesized by a new facile solvothermal method: An efficient electrocatalyst with Pt-like activity for hydrogen generation
PublicationWe report here a facile, template-free and one-step solvothermal approach for the synthesis of high-temperature stable gold/titania nanocomposite (NCs), providing a new, simple, quick and inexpensive wet-chemical route. Our approach is based on the assembly of gold salt and titanium butoxide in dimethyl sulfoxide (DMSO). Also, we present here, for the first time, a cathodically activated Au/TiO2 catalyst with Pt/C activity for...
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Understanding the origin of high corrosion inhibition efficiency of bee products towards aluminium alloys in alkaline environments
PublicationVarious bee products were found to be efficient corrosion inhibitors of aluminium in different environments. In particular, bee pollen was found to be highly effective in alkaline electrolytes, yet its highly complex composition and possible synergistic interactions hinder determination of the compounds acting as active corrosion inhibitors. The main purpose of the following work is to investigate the effect of solvents used for...
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Nanocrystalline cathode functional layer for SOFC
PublicationRecently, it was shown that thin functional layers introduced between an electrolyte and cathode might improve cathode performance. However, the mechanism of this improvement still needs analysis. In this paper, a thin (∼140 nm), spin-coated perovskite layer (La0.6Sr0.4Co0.2Fe0.8O3-δ) was placed between a cathode (La0.6Sr0.4Co0.2Fe0.8O3-δ) and an electrolyte (Ce0.8Gd0.2O2-δ) and the effects of this investigated. The microstructure...
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Synthesis and photoelectrochemical behaviour of hydrogenated titania nanotubes modified with conducting polymer infiltrated by redox active network
PublicationIn this work, we show preparation of ordered inorganic-organic composite electrode material where hydrogenated titania nanotubes H-TiO2 with tubularly developed surface modified with poly(3,4-ethylenedioxythiophene) matrix permeated by Prussian Blue (PB) inorganic redox network in order to reach highly photoactive heterojunction. The polymer deposition was realized via two subsequent processes covering: i) potentiostatic polymerization...
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Photocatalytical properties of maze-like MoO3 microstructures prepared by anodization of Mo plate
PublicationIn this work, we present a simple method of the formation of MoO3 microstructures via an electrochemical anodization of Mo plate carried out under varied conditions. The morphology, composition and structure of samples were investigated by SEM, EDX, XRD and Raman spectroscopy. The band gap energy was estimated using the Kubelka–Munk function and was found to be 2.87 eV. Finally, the photocatalytic activities of MoO3 samples were...
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Arylated carbon nanotubes for biobatteries and biofuel cells
PublicationSinglwalled carbon nanotubes (swcnts)covalently phenylated, napthylated or terphenylated were used for the construction of cathodes in a biobattery and in a biofuel cell. zn is the anode in the biobaterry and single-walled carbon nanotubes are covalently modified with glucose oxidase/catalase (swcnt-gox/cat) and the biofuel cell anode. the cell parameters were determined and the potentials of each of the electrodes under cell working...
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Impedance of cation-coupled electron transfer reaction: teoretical description of one pathway process
PublicationPrzyjęto możliwość występowanie dwóch wzajemnie sprzężonych reakcji. Opisana została impedancja sprzężonej reakcji przeniesienia elektronu z kationem. Wyznaczony został również model elektrycznego schematu zastępczego. Całkowita impedancja Faradayowska jest sumą impedancji przeniesienia elektronu i impedancji przeniesienia kationu. Przykłady pomiaru impedancyjnego w warunkach potencjostatycznych i potencjodynamicznych zostały omówione....
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Influence of the electrosynthesis conditions on the spontaneous release of anti-inflammatory salicylate during degradation of polypyrrole coated iron for biodegradable cardiovascular stent
PublicationIn this work, the spontaneous release of anti-inflammatory salicylate from polypyrrole (PPy) coated iron has been studied during degradation of the material in phosphate buffer saline at 37 C. The sodium salicylate was incorporated into PPy in a one-step electropolymerization process. The influence of the synthesis conditions such as sodium salicylate concentration, pyrrole concentration and deposition charge on drug release profile...
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Voltammetric and biological studies of folate-targeted non-lamellar lipid mesophases
PublicationFolate-targeted lipid nanostructures are promising strategies for the development of biocompatible drug delivery systems. The objective of this study was to evaluate the efficacy of drug delivery to cancer cells by folate-targeted lipid mesophases, cubosomes (CUB) and hexosomes (HEX), loaded with doxorubicin (DOX). Three cancer-derived cell lines (KB, HeLa, T98G) exhibiting different expressional levels of folate receptor protein...
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Study of oxygen electrode reactions on symmetrical porous SrTi0.30Fe0.70O3-δ electrodes on Ce0.8Gd0.2O1.9 electrolyte at 800 °C–500 °C
PublicationIron doped strontium titanates (SrTi1-xFexO3-δ) are an interesting mixed ionic-electronic conductor model used to study basic oxygen reduction/oxidation reactions. In this work, we performed an impedance spectroscopy study on symmetrical porous SrTi0.30Fe0.70O3-δ (STF70) electrodes on a ceriabased electrolyte. The sample was measured in varying oxygen concentration: from 0.3% to 100% in 800 °C - 500 °C temperature range. Low polarisation...
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SnO2 nanoparticles embedded onto MoS2 nanoflakes - An efficient catalyst for photodegradation of methylene blue and photoreduction of hexavalent chromium
PublicationIn this work, a molybdenum disulfide/tin oxide (MoS2/SnO2) composite was successfully prepared via a hydrothermal method. The MoS2/SnO2 composite was used as a photocatalyst for photoreduction of hexavalent chromium and photodecomposition of methylene blue. It exhibited higher photocatalytic performance under simulated solar light irradiation than MoS2 itself. The obtained material was characterized by several spectroscopic and...
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The effect of tensile stresses on aluminium passive layer durability
PublicationW niniejszej pracy przedstawiono wyniki badań DEIS dotyczących wpływu naprężeń rozciągających na trwałość warstwy pasywnej aluminium A91050, prowadzonych w środowisku chlorków w temperaturze pokojowej.Zastosowana technika pozwoliła na wyznaczenie krytycznej wartości wydłużenia, przy której doszło do pęknięcia warstwy pasywnej na badanym stopie.
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Selection of measurement frequency in Mott-Schottky analysis of passive layer on nickel
PublicationPrzedstawiono zależności Mott'a - Schottky'ego dla różnych częstotliwości pomiarowych. Kształt uzyskanych zależności zależy od doboru tych częstotliwości. Związane jest to z tym, że stężenie defektów w warstwie pasywnej zależy od doboru częstotliwości. Metoda DEIS pozwala na uniknięcie tych niedogodności.
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Ionophores in polymeric membranes for selective ion recognition:impedance studies
PublicationW pracy badano dwa typy elektrod: membranowe elektrody jonoselektywne (ISE) oraz elektrody nowego typu all-solid-state (AAS). Elektrody AAS zawierają przewodzącą warstwę polimerową na węglu szklistym lub platynie, na który nałożona jest membrana zawierająca jonofor. Do badań użyto dwa jonofory: p-tert-butylokaliks[4]aren-korona-4 (L1) selektywnie kompleksująca jony Na+ oraz kaliks[4]aren-korona-6 (L2) selektywnie kompleksująca...
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Optimalization of TiO2 nanotube geometry using fuzzy reasoning approach
PublicationThe geometry of TiO2 nanotube layer on titanium, obtained by electrochemical anodization, has been determined by using fuzzy reasoning approach. A proposed method showed the possibility of nanotube array architecture optimization by choosing an appropriate anodization condition. A fuzzy logic controller (FLC) was utilized using Matlab Software.
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Study of anticorrosion and microwave absprption properties of NiZn ferrite pigments
PublicationPurpose - The purpose of this paper is to report the electrochemical verification of anticorrosive properties of NiZn ferrites as pigments in protective coatings and evaluation of their microwave absorbing properties. Design/methodology/approach - Ferrites, represented by formula NixZn(1-x)Fe2O4, where x=0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a ceramic method. The samples of ferrites were examined by X-ray diffraction...
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Enhanced capacitance of composite TiO2 nanotube / boron-doped diamond electrodes studied by impedance spectroscopy
PublicationWe report on the novel composite nanostructures based on boron-doped diamond thin film grown on top of TiO2 nanotubes. The nanostructures made of BDD-modified titania nanotubes showed an increase in activity and performance when used as electrodes in electrochemical environments. The BDD thin films (~200-500 nm) were deposited using microwave plasma assisted chemical vapor deposition (MW PA CVD) onto anodically fabricated TiO2...
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Corrosion behavior of hydrogen charged super duplex stainless steel welded joints
PublicationThe electrochemical behavior of the weld metal, heat-affected zone (HAZ), and base material of super duplex stainless steel (SDSS) welded joints, made with the application of flux-cored arc welding (FCAW) and submerged arc welding (SAW), were investigated with the use of metallographic examinations (optical microscopy and scanning electron microscopy), potentiodynamic polarization measurements and total hydrogen content determination...
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The Effect of C45 Carbon Black-Phosphomolybdic Acid Nanocomposite on Hydrogenation and Corrosion Resistance of La2Ni9Co Hydrogen Storage Alloy
PublicationIn this paper, we analysed the influence of corrosion processes and the addition of a carbon black-heteropoly phosphomolybdic acid (C45-MPA) nanocomposite on the operating parameters of a hydride electrode obtained on the basis of the intermetallic compound La2Ni9Co. The electrochemical properties of negative electrodes for NiMH batteries were studied using galvanostatic charge/discharge curves, the potentiostatic method, and electrochemical...
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Tuning of the finesse coefficient of optoelectronic devices
PublicationOptoelectronic devices attracted considerable attention in many branches of science and technology, which can be attributed to their unique properties. Many of them use optical cavities which parameters can be adopted to specific requirements. This thesis investigates the introduction of diamond structures (nitrogen-doped diamond film, boron-doped diamond film, undoped diamond sheet) to optical cavities to tune their finesse coefficient....
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Multivariate analysis of impedance data obtained for coating systems of varying thickness applied on steel
PublicationElectrochemical impedance spectroscopy (EIS) has proven to be a valuable test method for the electrochemical characterization of protective coatings on metals. The common way of analysis in impedance spectroscopy is to model the impedance spectrum by means of an equivalent circuit and to extract the quantity of interest using optimization techniques. A model, corresponding to the behavior of the sample under testing, is important...
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Degradation of implantable materials – in vivo and in vitro research
PublicationThe article concerns the biological and electrochemical degradation of metallic implants in vivo and in vitro studies. The in vivo research dealt with degradation of plates used to join bones, as well as endoprostheses. The most common damages were: metalosis, breaking in the microstructure changes, breaking in area of holes, as well as plastic deformation throughout the length of an implant. The material used for the research...
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Effectiveness of a dual surface modification of metallic interconnects for application in energy conversion devices
PublicationA dual surface modification of an SOFC metallic interconnect with a Gd2O3 layer and an MnCo2O4 coating was evaluated. The tested samples were oxidized for 7000 h in air at 1073 K. Oxidation products were characterized using XRD, SEM-EDS, and confocal Raman imaging, and ASR was measured. The effect of gadolinium segregation at grain boundaries in Cr2O3 was evaluated using S/TEM-EDS. Area specific-resistance was measured and fuel...
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Chemorezystancyjny czujnik gazu na bazie polimeru przewodzącego PEDOT
PublicationPolimery przewodzące, takie jak Poli(3,4-etylenodioksytiofen) (PEDOT) są atrakcyjnymi materiałami elektrodowymi, które posiadają takie zalety, jak biokompatybilność, duża przewodność i elastyczność. Elektroprzewodzące polimery można otrzymać w wyniku chemicznej polimeryzacji lub elektropolimeryzacji. W niniejszej pracy przedstawiono zostanie koncepcja czujnika gazów składająca się z elektrody grzebieniowej oraz polimeru przewodzącego...
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Surface modifications of ti and its alloys
PublicationThis article reviews the various surface modification techniques pertaining to titanium and titanium alloys including physical treatment, mechanical treatment, and chemical and electrochemical treatment. The proper surface modification expands the use of titanium and its alloys in the biomedical field for long-term implants retaining the excellent properties of substrate material and improving the specific surface properties required...