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Understanding technical cleanliness: importance, assessment, maintenance

Faber Joanna, Brodzik Krzysztof, Nycz Marta

Combustion Engines

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2021

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R. 60, nr 3

41--50

EN

Development of the automotive industry, including so-called dowsizing and rightsizing, entails the need to ensure, and hence to verify, the stringent cleanliness levels of an increasing number of car components. The assurance of proper cleanliness level requires knowledge of the entire production process and precise information on the contaminants that will allow to identify their sources. Obtaining reliable cleanliness information requires establishing of many different factors, i. a. selection of proper contamination extraction and collection technique, proper parameters of extraction, validation of extraction procedure, methods of particles analysis. Analytical techniques which are implemented include gravimetric, optical microscopy and advanced techniques like scanning electron microscopy. This work present’s actual state of knowledge regarding technical cleanliness analysis of components. Important aspects of QA&QC in technical cleanliness assessment are also discussed.

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The affinity for dialysate species of thermally modified titania nanotubes under static and dynamic conditions

Jędrzejewska Aleksandra, Pasik Kamila, Nycz Marta, Arkusz Katarzyna

Acta of Bioengineering and Biomechanics

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2021

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Vol. 23, no. 4

95--105

EN

Purpose: During the dialysis process, hemolysis is the most frequently occurring problem to solve. Titanium dioxide nanotubes (TNTs) can be considered as a material preventing hemodialysis or blood species deposition thanks to their unique properties, i.e., hydrophilicity, smooth surface, and antibacterial. The purpose of this work was the electrochemical, chemical, and morphological characteristics of the TNTs and the evaluation of the possibility of using them as filter parts in dialysis techniques. Methods: The tests were carried out on as-formed TNTs with a diameter of 50 ± 5 nm and 1000 ± 100 nm in height, and TNTs thermally modified in air atmosphere temperatures ranging from 350 to 550 °C. Electrochemical and microscopic analyses were performed both in the static and dynamic system of dialysis fluid (flow rate: 250 cm3/min). Additionally, deposition or damage of blood cells was specified during the ex vivo dialysis experiment. Results: Obtained results proved relationship between electrochemical properties of TNTs and the method of their modification. The results demonstrated that the TNTs annealed at 450 °C TNTs can be potentially applied for constructions dialysis membrane in the hemodialysis area due to their most stable stationary potential in dialysate, the highest value of impedance modulus, and the most favourable electrokinetic properties. Additionally, it was confirmed that annealed process causes improvement of corrosion resistance and protective properties for TNTs in the dialysis fluid. Conclusions: The result allowed for the conclusion that annealing is responsible for reduction of adsorption properties of TNTs, though this titanium dioxide nanotube still can be used as filter part in haemodialysis.

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Influence of geometry and annealing temperature in argon atmosphere of TiO2 nanotubes on their electrochemical properties

Nycz Marta, Paradowska Ewa, Arkusz Katarzyna, Pijanowska Dorota Genowefa

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 1

165--177

EN

In this paper, electrochemical properties of the as-formed and thermally treated titanium dioxide (TiO2) nanotubes with diameter in the range of 20–100 nm and height in the range of 100–1000 nm were presented. In addition, the effects of annealing temperature (450–550 °C) on the electrochemical characteristics of these structures, as well as the influence of diameter and height of TiO2 nanotubes on these properties were examined. The results were referred to a compact TiO2 layer (100 nm thick). Methods: The electrochemical test included open circuit potential, impedance spectroscopy and cyclic voltammetry measurements. The scanning electron microscope with energy dispersive spectroscopy analyser, x-ray photoelectron spectroscopy, and x-ray diffraction analysers were used for surface morphology characterisation as well as elemental, phase and chemical composition of TiO2 layers. Results: It was found that nanotubes with the diameter of 50 and 75 nm (height of 1000 nm) annealed at 550 °C exhibit the lowest impedance and phase angle values. However, the voltammetric detection of potassium ferricyanide indicated that the closest to 1 Ipc /Ipa ratio were shown by nanotubes with a diameter of 50 and 75 nm annealed at 450 °C. Conclusions: On the basis of performed analysis, it can be stated that the TiO2 layer with nanotubes of 50 nm in diameter and of 1000 nm in height, annealed in 450 °C may be indicated as the ones having the most favourable sensing and biosensing properties.