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Order on the nano-scale

Katarzyna Siuzdak
ACADEMIA. The magazine of the Polish Academy of Sciences | 2016 | Nr 4 (48) Control | 15-17
Keywords titanium dioxide titanium dioxide application
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Abstract

Titanium dioxide (TiO2) is a popular pigment known as titania white. However, it has many other properties that support various applications.

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Authors and Affiliations

Katarzyna Siuzdak

Titanium dioxide as a safe additive to sunscreen emulsions

Marcin Janczarek Waldemar Szaferski
Chemical and Process Engineering | 2022 | vol. 43 | No 4 (3rd Seminar on Practical Aspects of Chemical Engineering PAIC 2022, 7–8 June 2022, Zaniemyśl, Poland. Guest editor: Prof. Marek Ochowiak) | 483-490 | DOI: 10.24425/cpe.2022.142288
Keywords sunscreen emulsions titanium dioxide photocatalysis
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Abstract

Titanium dioxide with its ability to be a UV light blocker is commonly used as a physical sunscreen in the cosmetic industry. However, the safety issues of TiO 2 application should be considered more in-depth, e.g., UV light-induced generation of reactive oxygen species which can cause DNA damage within skin cells. The proper modification of titanium dioxide to significantly limit its photocatalytic properties can contribute to the safety enhancement. The modification strategies including the process conditions and intrinsic properties of titanium dioxide were discussed. The selected examples of commercially available TiO 2 materials as potential components of cosmetic emulsions dedicated for sunscreens were compared in this study. Only rutile samples modified with Al 2O 3 and/or SiO 2 showed inhibition of photocatalytic activity.
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Authors and Affiliations

Marcin Janczarek
1
ORCID: ORCID
Waldemar Szaferski
1
ORCID: ORCID
  1. Poznan University of Technology, Institute of Chemical Technology and Engineering, Berdychowo 4, 60-965 Poznan, Poland

Influence of diffusion on the reaction of sulfuric acid with ilmenites

Maciej Jabłoński Krzysztof Lubkowski Elwira Wróblewska
Chemical and Process Engineering: New Frontiers | 2023 | vol. 44 | No 3 (24th Polish Conference of Chemical and Process Engineering, 13-16 June 2023, Szczecin, Poland. Guest editor: Prof. Rafał Rakoczy and 8th European Process Intensification Conference, 31.05–2.06.2023, Warsaw, Poland.) | e23 | DOI: 10.24425/cpe.2023.146725
Keywords titanium dioxide pigments ilmenites thermokinetics diffusion
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Abstract

The reaction of ilmenite raw materials with sulfuric acid has been investigated to find out the influence of diffusion processes on the course of this reaction. Three different laboratory methods were used to initiate the reaction: mixing ilmenite with 83–85% sulfuric acid at a temperature of 80 °C, mixing ilmenite with 90% sulfuric acid at temperatures of 20–40 °C and adding water, and mixing ilmenite with water and adding 95% sulfuric acid. Changes of thermal power during the process (thermokinetics) were studied with the use of calorimetry. It was found that diffusion processes play an important role when the reaction is initiated by mixing ilmenite with water followed by the addition of sulfuric acid and are less important when the reaction is initiated by mixing ilmenite with concentrated sulfuric acid followed by the addition of water. To explain the influence of diffusion processes on the reaction, the model calculations based on mass and heat balance equations were involved. Model calculations showed that the diffusion and mass transport processes are so fast that the reaction kinetics is mainly influenced by the reaction on the surface of ilmenite particles. The adopted model of calculations showed a very good agreement with experimental results.
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Authors and Affiliations

Maciej Jabłoński
1
Krzysztof Lubkowski
1
ORCID: ORCID
Elwira Wróblewska
1
ORCID: ORCID
  1. West Pomeranian University of Technology Szczecin, Faculty of Chemical Technology and Engineering, Department of Organic and Physical Chemistry, Al. Piastów 42, 71-065 Szczecin, Poland

Solar cells based on copper oxide and titanium dioxide prepared by reactive direct-current magnetron sputtering

Grzegorz Wisz Paulina Sawicka-Chudy Maciej Sibiński Zbigniew Starowicz Dariusz Płoch Anna Góral Mariusz Bester Marian Cholewa Janusz Woźny Aleksandra Sosna-Głębska
Opto-Electronics Review | 2021 | 29 | 3 | 97-105 | DOI: 10.24425/opelre.2021.139039
Keywords solar cells copper oxides titanium dioxide reactive magnetron sputtering
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Abstract

In this study, solar cells based on copper oxide and titanium dioxide were successfully manufactured using the reactive direct-current magnetron sputtering (DC-MS) technique with similar process parameters. TiO2/CuO, TiO2/Cu2O/CuO/Cu2O, and TiO2/Cu2O solar cells were manufactured via this process. Values of efficiencies, short-circuit current, short-circuit current density, open-circuit voltage, and maximum power of PV devices were investigated in the range of 0.02÷0.9%, 75÷350 µA, 75÷350 µA/cm2, 16÷550 mV, and 0.6÷27 µW, respectively. The authors compare solar cells reaching the best and the worst conversion efficiency results. Thus, only the two selected solar cells were fully characterized using I-V characteristics, scanning electron microscopy, X-ray diffraction, ellipsometry, Hall effect measurements, and quantum efficiency. The best conversion efficiency of a solar cell presented in this work is about three times higher in comparison with the authors’ previous PV devices.
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Bibliography

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Authors and Affiliations

Grzegorz Wisz
1
ORCID: ORCID
Paulina Sawicka-Chudy
1
ORCID: ORCID
Maciej Sibiński
2
ORCID: ORCID
Zbigniew Starowicz
3
ORCID: ORCID
Dariusz Płoch
1
ORCID: ORCID
Anna Góral
3
Mariusz Bester
1
ORCID: ORCID
Marian Cholewa
1
Janusz Woźny
4
ORCID: ORCID
Aleksandra Sosna-Głębska
2
  1. Institute of Physics, College of Natural Science, University of Rzeszów, 1 Pigonia St., 35-317 Rzeszów, Poland
  2. Department of Semiconductor and Optoelectronic Devices, Łódź University of Technology, 211/215 Wólczańska St., 90-924 Łódź, Poland
  3. Institute of Metallurgy and Materials Science, Polish Academy of Sciences, 25 Reymonta St., 30-059 Kraków, Poland
  4. Department of Semiconductor and Optoelectronic Devices, Łódź University of Technology, 211/215Wólczańska St., 90-924 Łódź, Poland

Modelling particle deagglomeration in a batch homogenizer using full CFD and mechanistic models

Radosław Krzosa Krzysztof Wojtas Jakub Golec Łukasz Makowski Wojciech Orciuch Radosław Adamek
Chemical and Process Engineering | 2021 | vol. 42 | No 2 | 105-118 | DOI: 10.24425/cpe.2021.137344
Keywords population balance titanium dioxide CFD breakup high shear impeller
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Abstract

Modelling of titanium dioxide deagglomeration in the mixing tank equipped with a high shear impeller is presented in this study. A combination of computational fluid dynamics with population balance was applied for prediction of the final particle size. Two approaches are presented to solve population balance equations. In the first one, a complete population balance breakage kinetics were implemented in the CFD code to simulate size changes in every numerical cell in the computational domain. The second approach uses flow field and properties of turbulence to construct a mechanistic model of suspension flow in the system. Such approach can be considered as an attractive alternative to CFD simulations, because it allows to greatly reduce time required to obtain the results, i.e., the final particle size distribution of the product. Based on experiments shattering breakage mechanism was identified. A comparison of the mechanistic model and full CFD does not deviate from each other. Therefore the application of a much faster mechanistic model has comparable accuracy with full CFD. The model of particle deagglomeration does not predict a very fast initial drop of particle size, observed in the experiment, but it can predict, with acceptable accuracy, the final particle size of the product.
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Authors and Affiliations

Radosław Krzosa
1
Krzysztof Wojtas
1
Jakub Golec
1
Łukasz Makowski
1
Wojciech Orciuch
1
Radosław Adamek
2
  1. Warsaw University of Technology, Faculty of Chemical and Process Engineering, ul.Warynskiego 1, 00-645 Warsaw, Poland
  2. ICHEMAD–Profarb, ul. Chorzowska 117, 44–100 Gliwice, Poland

A new magnetic-hybrid photoreactor for photocatalytic water disinfection

Oliwia Paszkiewicz Kunlei Wang Marian Kordas Rafał Rakoczy Ewa Kowalska Agata Markowska-Szczupak
Chemical and Process Engineering: New Frontiers | 2023 | vol. 44 | No 3 (24th Polish Conference of Chemical and Process Engineering, 13-16 June 2023, Szczecin, Poland. Guest editor: Prof. Rafał Rakoczy and 8th European Process Intensification Conference, 31.05–2.06.2023, Warsaw, Poland.) | e22 | DOI: 10.24425/cpe.2023.146724
Keywords photocatalysis rotating magnetic field titanium dioxide disinfection water purification
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Abstract

Environmental contamination is an urgent topic to be solved for sustainable society. Among various pollutants, microorganisms are believed to be the most dangerous and difficult to be completely inactivated. In this research, a new hybrid photoreactor assisted with rotating magnetic field (RMF) has been proposed for the efficient removal of two types of bacteria, i.e., gram-negative Escherichia coli and gram-positive Staphylococcus epidermidis. Three selfsynthesized photocatalysts were used, based on commercial titanium(IV) oxide - P25, homogenized and then modified with copper by photodeposition, as follows: 0.5Cu@HomoP25, 2.0Cu@HomoP25 and 5.0Cu@HomoP25 containg 0.5, 2.0 and 5.0 wt% of deposited copper, respectively. The response surface methodology (RSM) was employed to design the experiments and to deteremine the optimal conditions. The effects of various parameters such as copper concentration [% w/w], time [h] and frequency of RMF [Hz] were studied. Results: Analysis of variance (ANOVA), revealed a good agreement between experimental data and proposed quadratic polynomial model ((R2=0.86 for E. coli and R2=0.69 for S. epidermidis). Experimental results showed that with increasing copper concentration, time and decreasing of frequency of RMF removal efficiency was increased. Accordingly, the water disinfection efficiency of 100% in terms of the independent variables was optimized, including cooper concentration c =5 % and 2.5% w/w, time t = 3 h and 1.3 h and frequency of rotating magnetic field f = 50 Hz and 26.6 for E.coli and S. epidermidis, respectively. This study showed that response surface methodology is a useful tool for optimizing the operating parameters for photocatalytic disinfection process.
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Authors and Affiliations

Oliwia Paszkiewicz
1
ORCID: ORCID
Kunlei Wang
2
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Rafał Rakoczy
1
ORCID: ORCID
Ewa Kowalska
2 3
ORCID: ORCID
Agata Markowska-Szczupak
1
ORCID: ORCID
  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technologyand Engineering, Department of Chemical and Process Engineering, Piastow 42, 71-065Szczecin, Poland
  2. Hokkaido University, Institute for Catalysis (ICAT), N21, W9, 001-0021 Sapporo, Japan
  3. Jagiellonian University, Faculty of Chemistry, Gronostajowa 2, 30-387 Krakow, Poland

Influence of calcination temperature on optical and structural properties of TiO2 thin films prepared by means of sol-gel and spin coating

T. Tański W. Matysiak D. Kosmalska A. Lubos
Bulletin of the Polish Academy of Sciences Technical Sciences | 2018 | 66 | No 2 (Special Section on Nano- and Micromechanics) | 151-156
Keywords TiO2 thin films spin coating optical properties structural properties calcination sol-gel titanium dioxide
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Authors and Affiliations

T. Tański
W. Matysiak
D. Kosmalska
A. Lubos

Corrosion Damage Mechanisms of TiO2 Cold-Sprayed Coatings

M.M. Lachowicz M. Winnicki
Archives of Metallurgy and Materials | 2022 | vol. 67 | No 3 | 975-985 | DOI: 10.24425/amm.2022.139691
Keywords titanium dioxide cold-sprayed coatings potentiodynamic polarization tests aluminum alloys structural steel
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Abstract

Cold spraying as a low-temperature coating deposition method is intended for thermally sensitive materials. Due to its precise temperature control, it limits the formation of structural defects, and can therefore be easily applied to spray corrosion protective coatings made from metal or metal-ceramic powders. However, the formation of pure ceramic coatings with the use of cold spraying is still not so common. Titanium dioxide is one of the most interesting ceramics due to its photocatalytic properties. Nevertheless, these types of coating materials usually work in a corrosion favoring humid atmosphere. In the presented paper, amorphous TiO2 powder was deposited onto aluminum alloys and steel substrates and then submitted to potentiodynamic corrosion tests in a 3.5 wt.% NaCl solution. The as-sprayed coating showed phase transition from amorphous TiO2 to anatase, and also revealed porosity. As a result, electrolytes penetrated the coating and caused undercoating corrosion in the tested environment of an aqueous NaCl solution. The analysis of the potentiodynamic curves showed that the presence of the coating decreased corrosion potential on both substrates. It arose from the mixed phases of TiO2, which consisted of photocathode – amorphous material and photoanode – crystalline anatase. The phase mixture induced the galvanic corrosion of metallic substrates in the presence of electrolytes. Moreover, pitting-like corrosion and coating delamination were detected in aluminium alloy and steel samples, respectively. Finally, the corrosion mechanism of the titanium dioxide coatings was characterized and described.
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Authors and Affiliations

M.M. Lachowicz
1
M. Winnicki
1
ORCID: ORCID
  1. Wrocław University of Science and Technology, Department of Metal Forming, Welding and Metrology, 5 Lukasiewicza S tr., 50-371 Wroclaw, Poland

Synthesis of magnesium aluminate spinel doped TiO2 from magnesite waste

N. Canikoğlu
Archives of Metallurgy and Materials | 2022 | vol. 67 | No 1 | 311-316 | DOI: 10.24425/amm.2022.137757
Keywords Magnesium aluminate spinel (MgAl2O4) Titanium dioxide (TiO2) Magnesite waste Alumina (Al2O3)
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Abstract

Magnesium aluminate spinel (MgAl2O4) is an important refractory material of magnesia origin. It is formed by the reaction of magnesium and aluminum oxides. In this study, TiO2 was added to magnesite waste and alumina (Al2O3) powders in different proportions and the mixtures were sintered at different temperatures after shaping. The aim of this study was to produce spinel economically by recycling waste materials. Therefore, titanium dioxide (TiO2) added magnesium aluminate spinel was produced and the products obtained were characterized by XRD and SEM-EDS analyses. In addition, bulk density, apparent porosity and microhardness values were measured and the effects of TiO2 additive on magnesium aluminate properties were examined. The better values were determined in samples doped 4 wt.% TiO2 at the sintering temperature of 1400°C.
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Authors and Affiliations

N. Canikoğlu
1
ORCID: ORCID
  1. Sakarya University, Engineering Faculty, Department of Metallurgical and Materials Engineering, Sakarya/Turkey

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