Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"Piotr LEDWIG"

Preparation and preliminary study of the properties of electrophoretically depositied nc-TiO2 coatings on 316L steel DOI:10.15199/28.2016.6.4

  TiO2 coatings on 316L steel were obtained by use of electrophoretic deposition (EPD) method. Potential zeta of nc-TiO2 particles in suspensions containing water and ethanol in different ratios was measured. Suspensions’ pH was stabilized by addition of acetic or citric acid and ammonia solution. Addition of citric acid in small amount decreased the zeta potential. Optimal suspensions’ parameters for cathodophoretic and anodophoretic deposition were selected based on the results of zeta potential measurements versus pH for suspensions with different water-ethanol concentration. For the chosen suspensions the rate of TiO2 deposition was measured. Coatings’ cohesion was improved by sintering or addition of biopolymer (chitosan) into suspension. The microstructure of coatings was examined by scanning electron microscopy. The roughness and thickness of the coatings were measured by optical profilometer. The corrosion resistance in Ringer’s solution was examined by use of polarization curves. The corrosion resistance of coated steel was higher than that of uncoated one. For sintered coatings the corrosion currents were lower, but the passive area was larger for not sintered ones. The contact angle of the coatings was measured using a sitting drop method and superhydrophilic properties of TiO2 coatings were confirmed. Manufactured coatings may be potentially used as self-cleaning materials. Additionally, TiO2 coatings improve corrosion resistance of steel and exhibit good bactericidal properties. These characteristics may make this sort of materials potentially useful also for medical purposes. Key words: TiO2 coatings, electrophoretic deposition, 316L steel, zeta potential measurements, superhydrophilic coating.1. INTRODUCTION Stainless steel is commonly used in many areas, e.g. marine systems, nuclear, chemical, food, construction industries and biomedical purposes [1÷3]. A wide range of industrial applications is possible [...]

Polimerowe, ceramiczne i kompozytowe powłoki osadzane elektroforetycznie poprawiające wybrane właściwości materiałów metalowych DOI:10.15199/24.2016.4.7

  W pracy przedstawiono przykłady wytwarzania różnych powłok polimerowych, ceramicznych i kompozytowych na modelowych materiałach metalowych metodą osadzania elektroforetycznego. W celu uzyskania dobrej jakości powłok dobrano optymalny skład chemiczny roztworów koloidalnych i zawiesin stosowanych do osadzania, wyznaczono ich pH i potencjał elektrokinetyczny dzeta. W oparciu o badania makroskopowe osadzonych powłok dobrano napięcie prądu i czas osadzania elektroforetycznego. Wykonano badania mikrostruktury powłok i ich wybranych właściwości, takich jak odporność na korozję, odporność na zużycie ścierne i wyznaczono współczynnik tarcia. Wykazano, że osadzanie elektroforetyczne jest perspektywiczną metodą wytwarzania powłok: polimerowych (chitozanu i polieteroeteroketonu (PEEK)), ceramicznych (SiO2), kompozytowych (szkło żelowe/chitozan, TiO2/chitozan, SiO2/HA i Ni/SiO2) oraz porowatych (szkło żelowe/PEEK). This work presents the examples of electrophoretic deposition of various polymer, ceramic and composite coatings on model metallic materials. To obtain good quality coatings, chemical composition of colloidal solutions and suspensions as well as their pH and Zeta potential were optimized. The voltage and deposition time were experimentally selected by macroscopic examination of as-deposited coatings. Investigation of the coatings comprised microstructural analysis as well as determination of their corrosion resistance, wear resistance and friction coefficient. It was demonstrated that electrophoretic deposition is a prospective method for obtaining various coatings: polymer chitosan and polyetheroetheroketone (PEEK), ceramic SiO2, composite gel glass/chitosan, TiO2/chitosan, SiO2/HA and Ni/SiO2 as well as porous sol-gel glass/PEEK coatings. Słowa kluczowe: osadzanie elektroforetyczne, powłoki polimerowe, powłoki kompozytowe, mikrostruktura, odporność korozyjna, odporność na zużycie ścierne Key words: electrophoretic deposition, polymer coatin[...]

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