Publikace vydané Univerzitou Pardubice / Published by the University of Pardubice
Stálý URI pro tuto komunituhttps://hdl.handle.net/10195/37631
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Článek Otevřený přístup peer-reviewedpublished Effect of concentration of zinc-powder in epoxy-ester based anticorrosive coatings(University of Pardubice, 2023) Raycha, Yash; Kohl, Miroslav; Kalendová, Andréa; Adam, MartinThe present work is directed to study the effect of zinc powder concentration on anticorrosive efficiency of epoxy ester resin-based anticorrosive coatings. A high performance of zinc coating for metal protection is of vital importance depending on the concentration of zinc incorporated into coating formulation. Zinc pigment gives protection against corrosion by cathodic protection and barrier protection mechanism; however, it is necessary to keep adequate dosage of zinc. A lower dosage of zinc is insufficient to obtain sufficient cathodic protection while much higher concentration leads to the pores in the film which may influence corrosion. Therefore, this study was focused on the development of highly effective zinc coatings for excellent anticorrosion protection, as well as mechanical performance, when using standardized tests on corrosion, mechanical and chemical properties.Článek Otevřený přístup peer-reviewedpublished Polyfluorene derivatives as a promising candidate for coating application(University of Pardubice, 2023) Mechergui, Imen; Piana, Francesco; Kohl, Miroslav; Kalendová, Andréa; Adam, MartinThis paper is focused on the synthesis and the characterization of one of the cationic water-soluble conjugated polymers based on polyfluorene (PF) derivatives with terminal amino-groups named poly(9,9-bis(2-(N-ethan(pyrolin-1-yl))ethan)fluorene dibromide (shortly abbreviated as "para phenyl") synthesized by Suzuki-Miyaura coupling reaction and quaternized through a bromoalkylation on pyrrolidine groups, giving rise to a conjugated ammonium polyelectrolyte (P2). The structure of the obtained polyfluorene derivatives (P1 and P2) was confirmed by 1H NMR and FTIR and their photophysical, electrical, and electrochemical properties fully investigated. The results show that the new polyfluorene electrolyte could be a strong candidate as a coating material thanks to its chemical stability and high conductivity.Článek Otevřený přístup peer-reviewedpublished Study on the properties of new anti-corrosion pigments containing Mg2+ cation in epoxy ester resin-based coatings(University of Pardubice, 2023) Boštíková, Karolína; Kalendová, Andréa; Kohl, Miroslav; Adam, MartinThe aim of the work was to study the protective properties of epoxy ester coatings containing newly synthesized organic pigments based on azo compounds in dependence of their chemical composition and concentration. For applications in anti-corrosion coatings, organic pigments containing the Mg2+ cation with expected anti-corrosion properties have been newly synthesized and their effect on epoxy ester coatings' physicochemical and corrosion resistance studied. In the same effort, inorganic oxides with Mg2+ cation content based on periclase and mixed magnesium-iron oxide and an industrial standard were also tested, the effectiveness of which had already been confirmed in previous studies. The properties of the prepared paint materials and organic coatings were investigated using standardized physical-mechanical tests together with accelerated cyclic corrosion tests in simulated corrosive atmospheres and electrochemical linear polarization technique. The results obtained with the coatings based on tested pigments containing epoxy-ester resin have confirmed the corrosion-inhibiting effect of the newly synthesized pigments.Článek Otevřený přístup peer-reviewedpublished Evaluation of regular and decaffeinated (un)roasted coffee beans based on antioxidant capacity and total phenolic content(University of Pardubice, 2023) Klikarová, Jitka; Řeháková, Barbora; Česlová, Lenka; Adam, MartinIn this study, the effect of coffee beans processing (decaffeination and roasting) on their antioxidant capacity and total phenolic content has been investigated. In a total of 64 regular as well as decaffeinated (un)roasted coffee samples, these characteristic parameters were determined spectrophotometrically using the DPPH free-radical method and the Folin-Ciocalteu assay. While the total phenolic content remained unchanged regardless of the processing method used, the antioxidant capacity of the samples varied depending on their treatment being affected mainly by the decaffeination procedure chosen.Článek Otevřený přístup peer-reviewedpublished Catecholase biomimetic copper(II) complex immobilization via Schiff's base formation onto the cross-linked polymers prepared by drop-casting(University of Pardubice, 2022) Sýs, Milan; Bártová, Michaela; Hartmanová, Aneta; Mikysek, Tomáš; Adam, MartinIn this article, a universal protocol is introduced dealing with covalent immobilization of catecholase biomimetic copper(II) complexes with free carbonyl group onto the primary amine-based polymeric substrates (chitosan and collagen, type II) cross-linked with glutar-aldehyde; both being enabled via Schiff's base formation. As a representative of biomimetic catalysts, [Cu2Ac2O(L)ClO4] consisting of a 2,6-bis(4-methyl piperazin-1-ylmethyl)- 4-formyl-phenoxy ligand (L) was selected. The resulting functionalized polymers formed at the surface of a screen-printed carbon electrode were characterized using scanning electron microscopy with energy dispersive X-ray analysis. As a result, the procedure presented herein could find use in the development of artificial biosensors.Článek Otevřený přístup peer-reviewedpublished Changes in concentrations of 5-hydroxymethylfurfural, carbohydrates, and ethanol during the mead production(University of Pardubice, 2022) Klikarová, Jitka; Melicharová, Šárka; Řezková, Soňa; Česlová, Lenka; Adam, MartinThis work is focused on monitoring changes in the concentrations of 5-hydroxymethylfurfural, ethanol, and carbohydrates during the mead production using various analytical techniques, namely micellar electrokinetic chromatography with spectrophotometric detection, gas chromatography coupled to flame-ionization detector, and hydrophilic interaction liquid chromatography with refractive-index detector, respectively. In this study, production of three mead samples made by different Czech beekeepers has been monitored. The individual mead fractions were regularly sampled for two months of fermentation and always analysed with the aid of the optimised analytical approach.Článek Otevřený přístup peer-reviewedpublished Gadolinium of anthropogenic origin in food crops(University of Pardubice, 2022) Josefová, Dominika; Mišíková, Frederika; Krejčová, Anna; Patočka, Jan; Adam, MartinThe study is focused on the monitoring of rare earth elements (REE) in food crops with particular interest paid to the evaluation of gadolinium of anthropogenic origin. Macroscopic fungi were used as they are culinary processed and being also a good indicator of environmental pollution. In total, 46 dried mushroom samples originating from the Czech Republic and Slovakia were analysed. When using microwave decomposition of samples and the elemental analysis of Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, Y, Yb using inductively coupled plasma mass spectrometry (ICP-MS), the respective analytical procedure was optimised and validated. The study also included the calculation of the gadolinium anomaly in the processed samples, as well as the calculation of the amount of anthropogenic gadolinium. In the case of the gadolinium monitored, the minimum value found was 1.41 μg kg−1; the maximum being 361 μg kg−1, and the average 33.7 μg kg−1. The contribution of gadolinium of the anthropogenic origin ranged from 0.77 to 270 g kg−1.Článek Otevřený přístup peer-reviewedpublished Advances in perovskite doping – SrTiO3 with cobalt ions(University of Pardubice, 2022) Fejk, Jiří; Dohnalová, Žaneta; Honcová, Pavla; Adam, MartinThis paper supports the point of research on doping of inorganic materials – in this case, pigments – with various elements. Compounds on the basis of SrTiO3 with individually substituted titanium positions for the cobalt ions have been prepared by the solid-state reaction boosted by the prior-to-made mechanoactivation. Calcination temperature and the molar ratio of reactants were varied in order to study their effect on the pigment synthesis. Powdered materials were characterised in terms of thermal behaviour and the phase composition. Particle size distribution and application possibilities in ceramic glaze and organic binder along with colour properties were subsequently determined for selected samples. The prepared set of pigments SrTi1–xCoxO3 (x = 0.1–0.9) differed in characteristics according to a diverse range of substitution and conditions of the synthesis.Článek Otevřený přístup peer-reviewedpublished Synthesis and antiproliferative activity of the salicyl-based Weinreb amides and their derivatives in cancer cell lines(University of Pardubice, 2022) Pilařová, Eliška; Jorda, Radek; Svobodová, Klára; Pauk, Karel; Kryštof, Vladimír; Imramovský, Aleš; Adam, MartinA series of 11 pseudotripeptide Weinreb amides and 8 pseudodipeptide sulfonylhydrazides were synthesized and assessed using the resazurin-based method to determine their antiproliferative activity against the following cancer cell lines: lymphoblastic leukaemia (CEM), acute myeloid leukaemia (MV4-11), multiple myeloma (U266), and breast adenocarcinoma (MCF-7). The investigated compounds have shown a mid-micromolar range of inhibition. When L-Trp was included in the centre of the tripeptide chain, the derivatives exhibited a single-digit micromolar activity against the MV4-11 and U266 cell lines. Further immunoblotting experiments and caspase-3/7 activity assays for the most active compound 3e have confirmed apoptosis as the mechanism of cell death.Článek Otevřený přístup peer-reviewed Comprehensive customer solutions in selected chemical product lines in the Czech Republic(University of Pardubice, 2022) Jelínková, Martina; Lošťáková, Hana; Adam, MartinThis paper aims to summarize the results of quantitative research striving to determine the importance of providing a comprehensive solution to the needs and requirements of buyers of the selected chemical products. It also aims to investigate the role of different components of products, services, and other aspects of offerings play as parts of a comprehensive solution designed for customers processing chemical products. The respondents were managers of enterprises purchasing the examined categories of chemical products in the Czech Republic and our research took place in 2021. Its outcomes show that a comprehensive solution of the needs and requirements of customers in the case of chemical products is perceived far more broadly than those hitherto presented in the literature. In general, it differs especially in the phase of research and development of delivered products, in the phase of consulting and cooperation with customers in harmonizing the technology of processing the products, as well as in the aspects of providing additional services and waste disposal.