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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.

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Homogeneous Coatings of Titanium Dioxide Nanoparticles on Corona-Treated Cotton Fabric for Enhanced Self-Cleaning and Antibacterial Properties

Aalipourmohammadi Mojtaba, Davodiroknabadi Abolfazl, Nazari Ali

Autex Research Journal

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2021

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Vol. 21, no. 1

101--107

EN

This study discusses the effect of corona pretreatment and subsequent loading of titanium dioxide nanoparticles on self-cleaning and antibacterial properties of cellulosic fabric. The corona-pretreated cellulosic fabrics were characterized by fi eld emission scanning electron microscopy, and X-ray mapping techniques revealed that layers of the titania deposited on cellulose fi bers were more uniform than the sample without pre-corona treatment. The self-cleaning property of treated fabrics was evaluated through discoloring dye stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that self-cleaning and antibacterial properties of the corona-pretreated fabrics were superior compared to the sample treated with TiO2 alone. Moreover, using corona pretreatment leads to samples with good washing fastness.

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Fabrication of DSSCs with biebrich scarlet, alizarine cyanine green and evans blue dyes as new organic photosensitizers

Bose S., Genwa K. R.

Materials Science Poland

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2018

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Vol. 36, No. 4

655--661

EN

Dye sensitized solar cells are photoelectrochemical cells mimicking photosynthesis. They represent a new generation of solar cells which is intensively studied nowadays. This cell was fabricated using TiO2 nanoparticles coated on FTO glass, organic dyes as photosensitizer, PEDOT:PSS as counter electrode and iodide-triiodide as electrolyte. The present work aims at the use of low cost new organic dyes viz. biebrich scarlet, alizarine cyanine green and evans blue for DSSC as an alternative to metallic dyes. In the present work, I-V characteristics, energy or power conversion efficiencies of the dyes have been studied in different solvents. The photoelectrochemical properties of the dyes were observed under 1.5 AM condition.

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The dependence of mechanical properties on TiO2 nanoparticles concentration in hybrid hydrogel materials with potential use as bones scaffolds

Zazakowny K., Lewandowska-Łańcucka J., Mastalska-Popławska J., Kamiński K., Kusior A., Nowakowska M., Radecka M.

Engineering of Biomaterials

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2017

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Vol. 20, no. 143 spec. iss.

36

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TiO2 immobilised on biopolymer nanofibers for the removal of bisphenol A and diclofenac from water

Kudlek E., Silvestri D., Wacławek S., Padil V. V. T., Stuchlík M., Voleský L., Kejzlar P., Černík M.

Ecological Chemistry and Engineering. S

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2017

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Vol. 24, nr 3

417--429

EN

Recently electrospinning has gained significant attention due to unique possibilities to produce novel natural nanofibers and fabrics with controllable pore structure. The present study focuses on the fabrication of electrospun fibres based on gum karaya (GK), a natural tree gum, with polyvinyl alcohol (PVA), and functionalization of the membrane with TiO2 nanoparticles with further methane plasma treatment. The GK/PVA/TiO2 membrane was analyzed with several techniques including: fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), and water contact angle, in order to characterize its morphological and physicochemical properties. The GK/PVA/TiO2 membrane was further successfully used for the degradation (under UV irradiation) of bisphenol A and diclofenac from aqueous solution. It was also observed that the degradation kinetics of these compounds are faster in comparison to the UV treatment alone.

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Performance of dye-sensitized solar cell fabricated using titania nanoparticles calcined at different temperatures

Kaur M., Verma N. K.

Materials Science Poland

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2013

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Vol. 31, No. 3

378--385

EN

Synthesis of titania (TiO2) nanoparticles by sol-gel method and their calcination at different temperatures, viz 450 C, 550 C and 650 C (defined as T450, T550 and T650) has been done. Structural analysis indicates that the T450 sample possesses anatase phase. The phase transformation to rutile starts occurring at T550, and, on increasing the calcination temperature, the crystallization and percentage of rutile phase increases. As the temperature increases from 450 to 650 C, the crystallite size increases by about a factor of two from 11.5 to 20.2 nm. From SEM micrographs, T550 electrode has been found to have appropriate aggregation, which led to enhanced dye desorption, as compared to T450 and T650 based electrodes. TEM images of the synthesized nanoparticles reveal that the particle size increases from 7 to 28 nm on increasing the calcination temperature from 450 to 650 C. From the photoluminescence and Fourier transform infrared studies, it has been concluded that the surface OH- groups are reduced on calcination, which affects the electron injection efficiency. The dye sensitized solar cell, fabricated using T550 sample, having a ratio of anatase/rutile 89:11, has been found to achieve the highest conversion efficiency.