| 1. |
- Kehoe, Laura, et al.
(author)
-
Make EU trade with Brazil sustainable
- 2019
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
-
Journal article (other academic/artistic)
|
|
| 2. |
- Mohl, Melinda, et al.
(author)
-
Titania nanofibers in gypsum composites : an antibacterial and cytotoxicology study
- 2014
-
In: Journal of Material Chemistry B. - : Royal Society of Chemistry. - 2050-750X .- 2050-7518. ; 2:10, s. 1307-1316
-
Journal article (peer-reviewed)abstract
- Further developments of antibacterial coatings based on photocatalytic nanomaterials could be a promising route towards potential environmentally friendly applications in households, public buildings and health care facilities. Hereby we describe a simple chemical approach to synthesize photocatalytic nanomaterial-embedded coatings using gypsum as a binder. Various types of TiO2 nanofiber-based photocatalytic materials (nitrogen-doped and/or palladium nanoparticle decorated) and their composites with gypsum were characterized by means of scanning (SEM) and transmission (TEM) electron microscopy as well as electron and X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX) techniques. These gypsum-based composites can be directly applied as commercially available paints on indoor walls. Herein we report that surfaces coated with photocatalytic composites exhibit excellent antimicrobial properties by killing both methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) under blue light. In the case of MSSA cells, the palladium nanoparticle-decorated and nitrogen-doped TiO2 composites demonstrated the highest antimicrobial activity. For the MRSA strain even pure gypsum samples were proven to be efficient in eradicating Gram-positive human pathogens. The cytotoxicity of freestanding TiO2 nanofibers was revealed by analyzing the viability of HeLa cells using MTT and fluorescent cell assays.
|
|
| 3. |
- Sarkar, Anjana, 1978-, et al.
(author)
-
Photocatalytic activity of TiO2 nanoparticles : effect of thermal annealing under various gaseous atmospheres
- 2012
-
In: Nanotechnology. - : Institute of Physics Publishing (IOPP). - 0957-4484 .- 1361-6528. ; 23:47, s. 475711-475719
-
Journal article (peer-reviewed)abstract
- The structure, composition and photocatalytic activity of TiO2 nanoparticles annealed in various gas atmospheres (N2, NH3 and H2) were studied in this work. The effect of treatment on crystal structure, particle size, chemical composition and optical absorbance were assessed by means of x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy and diffuse optical reflectance/transmittance measurements, respectively. Photocatalytic properties of the materials were evaluated by three different methods: degradation of methyl orange in water, killing of Staphylococcus aureus bacteria and photogeneration of radicals in the presence of 3-carboxy-2,2,5,5-tetramethyl pyrrolidine-1-oxyl (PCA) marker molecules. The results indicate that the correlation between pretreatment and the photocatalytic performance depends on the photocatalytic processes and cannot be generalized.
|
|
| 4. |
- Thörnberg, Jimmy, et al.
(author)
-
Oxidation resistance and mechanical properties of sputter-deposited Ti0.9Al0.1B2-y thin films
- 2022
-
In: Surface & Coatings Technology. - : Elsevier Science SA. - 0257-8972 .- 1879-3347. ; 442
-
Journal article (peer-reviewed)abstract
- Direct-current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS) were used to deposit understoichiometric Ti(1-x)Al(x)B(2-y )diboride coatings by sputtering from a segmented TiB2-AlB2 target using Ar and Kr as sputtering gas. For films with a fixed Al/(Ti + Al) ratio of x = 0.1 (Ti0.9Al0.1B2-y), the B content was varied with y & ISIN; (0.1, 0.6 and 0.7). For films with a fixed y = 0.7 (Ti1-xAlxB1.3), the Al content was varied with x & ISIN; (0.1, 0.4 and 0.7). Evaluation of the mechanical properties of the Ti1-xAlxB1.3 samples showed a reduction in both hardness and elastic modulus with increasing Al concentration, while the Ti0.9Al0.1B2-y samples showed a hardness increase with decreasing B content. Thus, Ti0.9Al0.1B1.3 films exhibited a superior hardness of 46.2 +/- 1.1 GPa and an elastic modulus of 523 & PLUSMN; 7 GPa, compared to the values for Ti0.9Al0.1B1.4 and Ti0.9Al0.1B1.9, showing a hardness of 44 +/- 1 GPa and 36 +/- 1 GPa, and an elastic modulus of 569 +/- 7 GPa and 493 +/- 6 GPa, respectively. The oxidation behavior of the mechanically most promising Ti0.9Al0.1B2-y sample series was investigated through air-annealing at 600 C for durations from 1 h to 10 h. All films formed a mixed non-conformal Al2O3-TiO2 oxide scale which acts as an inward and outward diffusion barrier, significantly reducing the oxidation rate compared to TiBz films, which form an oxide scale consisting of porous TiO2. The thinnest oxide scale after 10 h was found in the B-deficient samples, Ti0.9Al0.1B1.3 and Ti0.9Al0.1B1.4, at ~200 nm, which is significantly below that for Ti0.9Al0.1B1.9 at 320 nm. The enhanced oxidation resistance of highly understoichiometric films is due to the elimination of the B-rich tissue phase that is present at the grain boundaries for higher B content, where the latter has been shown to enhance the rate of oxidation in borides.
|
|
