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1

Ammonia level sensor using tapered optical fiber coated with titanium dioxide-incorporated porphyrin

Parasuti Frazna, Hikmawati Dyah, Trilaksana Herri, Yasin Moh.

Optica Applicata

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2023

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Vol. 53, nr 3

353--361

EN

Since ammonia is water-soluble, environmental studies have shown that the industrial waste such as fertilizer manufacturing, food products, palm oil, urea fertilizer industry can cause very serious damage to water body ecosystems if not properly managed, resulting in a decrease in water quality. Devices based on optical technology, especially devices that combine optical fibers and nanomaterials, are identified as highly sensitive to the species of interest by detecting changes in physicochemical properties. A practical, easy-to-use, inexpensive instrument for detecting ammonia level was proposed using tapered optical fiber (TOF) coated with titanium dioxide-incorporated porphyrin. TOF was fabricated by simultaneously stretching and heating. The preparation of TiO2/porphyrin/gelatine was prepared to coat tapered optical fiber by dipping. SEM analysis shows an increase in length and a decrease in diameter, also the successful coating of titanium dioxide and porphyrin in the taper region. The EDX analysis also proves the presence of the Ti element in the TOF layer. The TOF produces significant sensing performances toward the ammonia liquid concentration level. The TOF coated with titanium dioxide-incorporated porphyrin can detect a one ppm difference in ammonia concentration with a certain range of output voltage for every concentration has.

2

Simultaneous photooxidation and photoreduction of phenol and Cr(VI) ions using titania modified with nanosilica

Kądziołka Daria, Grzechulska-Damszel Joanna, Schmidt Beata

Polish Journal of Chemical Technology

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2022

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Vol. 24, nr 4

23--29

EN

The photocatalytic process of phenol oxidation and Cr(VI) reduction in the presence of nano-silica modified titania was carried out. The activity of composites was tested using two different light sources. The photocatalysts with 10% of nanosilica showed the highest activity. The calcination temperature (200–800 °C) significantly determined the sensitivity of the obtained materials to the light source used. Photocatalysts alternately adsorbed and desorbed Cr(VI) ions from the reaction mixture during irradiation. In the one-component mixture, complete oxidation of phenol was observed using material calcined at 650 °C, after 3 h of UV-VIS irradiation. In the reaction mixture of Cr(VI) and phenol, the highest activity was demonstrated by photocatalyst calcined at 300 °C. The concentration of phenol decreased in proportion to the decrease of chromium ions. The obtained titania-silica composites showed oxidizing properties towards phenol and reductive properties toward Cr(VI) ions.

3

Structural and photocatalytic properties of Ni-TiO2 photocatalysts prepared by mechanochemical synthesis assisted with calcination

Kucio Karolina, Charmas Barbara, Zięzio Magdalena, Pasieczna-Patkowska Sylwia

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 150348

EN

In the study the mechanochemical synthesis in the planetary ball mill was used to prepare photocatalytic materials obtained on the basis of TiO2 and nickel(II) acetylacetonate as a Ni2+ source. Three materials with different contents of Ni2+: 5, 10 and 20% wt. were prepared. The obtained materials were calcinated at 800°C for 1 h. Their physicochemical properties were investigated using the N2 adsorption/desorption, FT-IR/PAS, XRD, UV-Vis/DRS and SEM methods. Additionally, thermal stability of the obtained materials was examined (TGA/DTG/DTA). Photocatalytic activity of the samples was tested in relation to the aqueous solution of Safranin T (initial concentration C0 = 1×10-5 mol L-1) at the visible light (Vis). The results indicate that the mechanochemical synthesis is an effective and simple method for preparing materials with photocatalytic properties. All obtained materials were characterized by greater photocatalytic activity compared to the initial TiO2.

4

Biological synthesis and characterization of titanium dioxide nanoparticle from Cynodon dactylon

Renitta R. E., Jebaseeli T. J., Dhanaraj A., Paul S.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 113, nr 1

31--41

EN

Purpose: There are several advantages of using a biological technique to produce nanoparticles versus a chemical method. The primary goal of this work is to characterize and biologically synthesize titanium dioxide (TiO2) nanoparticles from Cynodon dactylon. The characterization has experimented with UV-Vis Spectroscopy, EDX analysis, SEM, XRD, and FTIR. Design/methodology/approach: The suggested study uses a simple biological technique to accomplish the systematic biological synthesis of TiO2 nanoparticles utilizing Cynodon dactylon plant extract and titanium tetra isopropoxide as a precursor. UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD) are used to confirm the fabrication of the TiO2 nanoparticles. The plant extract as well as titanium-based nanoparticles of the herb, Cynodon dactylon will be tested for its antibacterial activity against human pathogens. This eco-friendly technique for nanoparticle synthesis is straightforward and adaptable to major commercial manufacturing and technological applications. Findings: Cynodon dactylon biosynthesis of TiO2 nanoparticles is efficient, nutrition dependent, does not employ hazardous compounds, and happens at neutral pH levels. The antibacterial study results show that TiO2 nanoparticles synthesized using Cynodon dactylon have good antibacterial properties. TiO2 nanoparticle method of action against bacteria is unknown. This is an alternative process for synthesising TiO2 nanoparticles, apart from other chemical protocols, since this is quick and non-toxic. The antimicrobial property of biologically synthesized TiO2 nanoparticles against Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii was tested at four different doses of 15 μl/mg, 25 μl/mg, 50 μl/mg, and 75 μl/mg. The present results revealed the 75 μl/mg concentration got the highest zone of inhibition (15, 13, 15 mm) for Acinetobacter baumannii, Staphylococcus aureus, and Escherichia coli. Research limitations/implications: Many nanoparticles smaller than 100 nm are firmly agglomerated with each other in the study. TiO2 nanoparticles absorb in the UV region of 200 to 400 nm. XRD measurements confirmed the presence of TiO2 nanoparticles in the biologically produced sample. In our work, EDX was used to confirm the existence of Ti after its synthesis by Cynodon dactylon. Practical implications: The biosynthesized TiO2 nanoparticles utilizing Cynodon dactylon plant extracts exhibit a good potent antibacterial activity. The proposed results showed that the TiO2 nanoparticles are well suited for biomedical applications. Originality/value: The suggested research identifies several eco-friendly, biological, and cost-effective procedures for manufacturing nano-coated herbal products. The agar well diffusion technique was used to assess antibacterial activities toward test pathogens such as Acinetobacter baumannii, Staphylococcus aureus, and Escherichia coli.

5

Selected properties of polypropylene-TiO2 composites after exposure to UV rays – preliminary study

Olesik Piotr, Peryt Aleksander, Stępień Krzysztof, Frączek Violetta, Mackiewicz Krzysztof, Molka Weronika, Musiał Oliwia, Różańska Weronika, Jesionek Marcin

Composites Theory and Practice

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2022

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R. 22, nr 1

21--24

EN

In this study the mechanical properties of polypropylene (PP) with a small amount of TiO2, after UV-C exposure were preliminarily analyzed. The effectiveness of titanium oxide was evaluated in two alternative applications: TiO2 as the polymer filler and TiO2 as a protective outer coating. The samples were exposed to UV-C rays for 1000 hours. It was found that an addition of 5 wt.% TiO2 to PP matrix results in a 60% smaller decrease in Rg after 1000 h of exposure to UV-C than in the case of neat polypropylene. It was also found that the addition of TiO2 to the polypropylene matrix is more effective than TiO2 applied as a coating component. The Rg decrease after exposure is about 35% in this case. The research confirmed that TiO2 submicrometric particles seem to be a very good component in reducing the sustainability of polypropylene to UV radiation.

6

Titanium dioxide as a safe additive to sunscreen emulsions

Janczarek Marcin, Szaferski Waldemar

Chemical and Process Engineering

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2022

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Vol. 43, nr 4

483-–490

EN

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 TiO2 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 TiO2 materials as potential components of cosmetic emulsions dedicated for sunscreens were compared in this study. Only rutile samples modified with Al2O3 and/or SiO2 showed inhibition of photocatalytic activity.

7

Synthesis of magnesium aluminate spinel doped TiO2 from magnesite waste

Canikoğlu Nuray

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

311--316

EN

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.

8

Corrosion Damage Mechanisms of TiO2 Cold-Sprayed Coatings

Lachowicz Marzena, Winnicki Marcin

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

975--985

EN

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.

9

Powłoki o właściwościach samoczyszczących aplikowane na materiały tekstylne

Masłowska-Lipowicz Iwona, Słubik Anna, Wyrębska Łucja

Technologia i Jakość Wyrobów

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2021

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R. 66

124--133

PL

Właściwości samoczyszczące powierzchni cieszą się dużym zainteresowaniem ze względu na szerokie możliwości ich zastosowań w różnych gałęziach przemysłu (tekstylia, budownictwo, urządzenia sanitarne, części samochodowe, panele fotowoltaiczne, urządzenia elektroniczne, lotnictwo, kosmonautyka i in.). Powierzchnie samoczyszczące mogą mieć właściwości hydrofobowe lub hydrofilowe. Samoczyszczące tekstylia umożliwiają oszczędzanie wody, środków piorących, energii i czasu. Ponadto, są odporne na przenikanie wody i kumulowanie zanieczyszczeń na ich powierzchni. Opracowano metodę modyfikacji tkaniny bawełnianej w celu nadania jej właściwości samoczyszczących. Metoda ta opiera się na aplikacji poli(dimetylosiloksanu) oraz nanometrycznego dwutlenku tytanu na tkaninę bawełnianą.

EN

Self-cleaning properties of surfaces are of great interest due to the wide range of their applications in various industries (textiles, construction, sanitary equipment, automotive parts, photovoltaic panels, electronic devices, aviation, aerospace, etc.). Self-cleaning surfaces can have hydrophobic or hydrophilic properties. Self-cleaning textiles allow saving water, detergents, energy and time. Moreover, they are resistant to water penetration and accumulation of contaminants on their surface A method of modifying cotton fabric in order to make it self-cleaning has been developed. This method is based on the application of poly(dimethylsiloxane) with terminal hydroxyl groups and nanometric titanium dioxide to cotton fabric.

10

Research on dielectric parameters of epoxy resin based nanocomposites using the impedance spectroscopy method

Dąda Anna, Błaut Paweł

Przegląd Elektrotechniczny

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2021

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R. 97, nr 12

234--237

EN

Due to the modern requirements regarding the reliability of electrical devices operation, research on improving the parameters of materials and insulation systems, in particular high-voltage ones, used in the production, transmission and distribution of electricity is still valid. One of the research directions is the development and application of insulating materials modified with nanofillers. The paper presents the results of stability studies of selected dielectric properties of samples of insulation materials based on epoxy resin modified with titanium dioxide TiO2 nanopowders. Changes in parameters caused by different wt% nanofiller content and their long-term stability after 10,000 hours from manufacturing are compared and analyzed.

PL

Współczesne wymagania dotyczące niezawodności pracy urządzeń elektrycznych powodują, że wciąż aktualnymi są badania dotyczące poprawy parametrów materiałów i układów izolacyjnych, w szczególności wysokonapięciowych, stosowanych w wytwarzaniu, przesyle i rozdziale energii elektrycznej. Jednym z kierunków badań jest opracowanie i zastosowanie materiałów izolacyjnych modyfikowanych nanowypełniaczami. Referat przedstawia wyniki badań stabilności wybranych właściwości dielektrycznych próbek materiałów izolacyjnych na bazie żywicy epoksydowej modyfikowanej nanoproszkami tlenku tytanu TiO2. Porównane są i analizowane zmiany parametrów powodowane różną zawartością wt% nanowypełniacza oraz ich stabilność długoczasowa po 10.000 godzin od wytworzenia.

11

The removal of Fe from the reduced ilmenite via aeration leaching assessing the effect of operating parameters

Ibrahim Siti Asmidar, Yunus Farhana, Ariffin Kamar Shah, Sheikh Abdul Hamid Sheikh Abdul Rezan, Ismail Suhaina, Jabit Nurul Ain

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 6

182--195

EN

An upgrade of Malaysian ilmenite (FeTiO3) concentrate to synthetic rutile (TiO2) using aeration leaching was investigated in this study. Carbothermal reduction using Sarawak MukahBalingan coal and compressed National Gas (CNG) as a reductant was used to produce reduced ilmenite (RI) as an intermediate phase consisting of titanium oxide matrix with metallic iron prior to aeration leaching. Metallic iron was dissolved in ammonium chloride solution after the reduction process, separating synthetic rutile in the leaching residue. This study aims to evaluate the leaching parameters, such as concentration, temperature, and leaching time. The optimum conditions established by the design of the experiment (DOE) and the analysis of variance (ANOVA) has indicated that leaching temperature was the most significant parameter for iron dissolution. It was found that iron dissolution at a maximum value of 97.0% was achieved at an optimum condition of 0.5 M NH4Cl at 90°C for 7 hours. With an initial weight of 46 wt.%TiO2 and 37 wt.% Fe2O3, ilmenite was successfully upgraded to 80 wt.% and 8 wt.%, respectively. In conclusion, Malaysian ilmenite has a high potential value to be upgraded to synthetic rutile by aeration leaching with ammonium chloride via Becher process.

12

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

Wisz Grzegorz, Sawicka-Chudy Paulina, Sibiński Maciej, Starowicz Zbigniew, Płoch Dariusz, Góral A., Bester Mariusz, Cholewa M., Woźny Janusz, Sosna-Głębska A.

Opto-Electronics Review

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2021

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Vol. 29, No. 3

97--104

EN

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 short-circuit current efficiencies, 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.

13

Characterisation of nano-thin film GO/TiO2 layers for Kretschmann-based surface plasmon resonance visible sensing using FDTD method

Khairulazdan N. B., Mohamed R., Berhanuddin D. D., Menon P. S.

Optica Applicata

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2021

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Vol. 51, nr 4

579--587

EN

Kretschmann-based surface plasmon resonance (K-SPR) is suitable for biomolecular sensing which provides label-free and quick detection results with real-time analysis. In this work, we have investigated the effect of graphene oxide (GO) with titanium dioxide (TiO2) thin films that are placed in hybrid above metal layers such as gold (Au), silver (Ag) and copper (Cu) with the presence of chromium (Cr) as an adhesive layer. The thickness of the Au, Ag and Cu metal thin films were optimized to 40, 30 and 30 nm, respectively, with a fixed thickness of GO of 2 nm and TiO2 of 1.9 nm. The sensing was evaluated for SPR excitation at three different visible wavelengths of 633, 670 and 785 nm. The performance of sensing was analyzed based on the reflectance intensity and full-width at half-maximum (FWHM) of the spectrum using the finite-difference time-domain (FDTD) method. The sensitivity was calculated for analyte sensing in dielectric mediums of air versus water. The sensitivity increment percentage (%∆S ) was determined when comparing analyte detection using Cr/metal and Cr/metal/GO/TiO2 sensor structures. The highest sensitivity of 94.51 deg/RIU was achieved for Cr/Cu/GO/TiO2 K-SPR sensor at 633 nm wavelength.

14

Innowacyjne cementowe kompozyty fotokatalityczne

Jackiewicz-Rek Wioletta, Chilmon Karol

Materiały Budowlane

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2021

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nr 3

48--50

15

Physico-mechanical properties, structure, and phase composition of (BeO + TiO2)-ceramics containing TiO2 nanoparticles (0.1–2.0 wt.%)

Pavlov Alexandr, Sagdoldina Zhuldyz, Kassymov Askar, Seitkanova Ainur, Rakhadilov Bauyrzhan, Kengesbekov Aidar

Materials Science Poland

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2021

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Vol. 39, No. 4

626--638

EN

This research studies the effects of addition of micro- and nanoparticles of TiO2 and variations in the firing temperature on the physico-mechanical properties of oxide-beryllium ceramics, shows the evolution of the microstructure of such ceramics during sintering, and presents the data of X-ray phase analysis. It was shown that the addition of TiO2 nanoparticles leads to a higher density of the ceramic material after sintering due to the interpenetration of TiO2 and BeO phases, which is caused by an increase in the diffusion mobility of atoms that can in turn be attributed to an increase in the imperfection of the structure and the fraction of grain boundaries. It was found that the presence of nanoparticles contributes to an increase in the apparent density of the material, as well as a decrease in its total and closed porosity; and an increase in the sintering temperature contributes to the transformation of the crystalline structure of TiO2 into a more conductive Ti3O5with an orthorhombic structure. The presence of nanoparticles also promotes self-healing of micropores, which can be explained by the blocking of a certain fraction of the interfaces between BeO particles by nanoparticles and the creation of a diffusion barrier.

16

Macro- and micromechanical response of glass fibre-reinforced polypropylene to pigmental impurities

Sikorski Ryszard

Composites Theory and Practice

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2021

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R. 21, nr 1-2

22--28

EN

The present study investigates the influence of pigmental impurities on glass fibre-reinforced polypropylene using model compounds to simulate the behaviour of recyclate-based compositions. Most industrial-quality (containing recyclate) PP compounds are black coloured (using carbon black pigment), with an almost unavoidable presence of inorganic white pigment (e.g. titanium dioxide) impurities. There are widespread beliefs in the compounding industry that such impurities have a detrimental effect on the mechanical properties of glass fibre-reinforced compounds, but up to now no systematic study of this problem from the industrial point of view has been reported. For this purpose, a range of compounds was prepared on a twin- screw compounding line and the properties were evaluated, with special focus on the mechanical properties. The results confirmed the strong influence of some white pigments, particularly titanium dioxide, and rejected the thesis of the detrimental action of carbon black.

17

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

Krzosa Radosław, Wojtas Krzysztof, Golec Jakub, Makowski Łukasz, Orciuch Wojciech, Adamek Radosław

Chemical and Process Engineering

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2021

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Vol. 42, nr 2

105–-118

EN

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.

18

The optical parameters of TiO2 antireflection coating prepared by atomic layer deposition method for photovoltaic application

Szindler Marek, Szindler Magdalena M.

Optica Applicata

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2020

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Vol. 50, nr 4

663--670

EN

Titanium dioxide thin films have been deposited on silicon wafers substrates by an atomic layer deposition (ALD) method. There optical parameters were investigated by spectroscopic ellipsometry and UV/VIS spectroscopy. A material with a refractive index of 2.41 was obtained. Additionally, in a wide spectral range it was possible to reduce the reflection from the silicon surface below 5%. The Raman spectroscopy method was used for structural characterization of anatase TiO2 thin films. Their uniformity and chemical composition are confirmed by a scanning electron microscope (SEM) energy dispersive spectrometer (EDS).

19

Czarne chmury nad białym betonem

Solecki Andrzej

Materiały Budowlane

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2020

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nr 9

58--59

20

Nano-modified cementing composites for self-cleaning building materials

Sanytsky Myroslav, Kropyvnytska Tetiana, Hohol Marko, Kotiv Roman

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

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2020

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Vol. 9 Nr 1

7--14

EN

This paper is devoted to the development of nano-modified cementing composites in the field of self-cleaning building materials. Particle-size distributions of the main constituents such as ultra-fine zeolite and limestone of multicomponent cements, and titanium dioxide and kaolin additives are given. The degree of the interphase of the active surface in Portland cement and supplementary cementitious materials is calculated. It has been shown that due to the synergistic effect, anatase and rutile mixtures can be included in cementing composites to improve the properties of self-cleaning plasters. The influence of titanium dioxide and kaolin additives on the mechanical properties of nano-modified multicomponent cement was investigated using the method of mathematical planning for the experiment. The results obtained using the XRD and SEM methods showed that the addition of high-surface-area nano-scale particles of TiO2 to the cement paste leads to the formation of a denser microstructure in the cementing matrix.