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Industrial Applications
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
Lian et al. (2005) have performed ion implantations in bulk samples of single-crystal lanthanide titanate pyrochlores A2Ti2O7 (A = Sm, Eu, Gd, Dy and Er) using 1.0 MeV Kr+ at room temperature at an ion fluence of 5 × 1014 ions/cm/. Er2Ti2O7 was also implanted by 1 MeV Kr+ at an ion fluence of 1.74 × 10 14 ions/cm2. Ion implantation-induced microstructural evolution has been examined using cross-sectional TEM. For Er2Ti2O7 irradiated by 1 MeV Kr+ at a dose of 1.4 × 1014 ions/cm2, a highly damaged layer consisting of nano-sized disordered fluorite domains was observed. On other hand, a complete amorphous layer starting from surface was created by 1 MeV Kr+ implantation at a fluence of 5 × 1014 ions/cm2. The critical amorphization doses of different titanate pyrochlore single crystals implanted with 1 MeV Kr+ were determined by comparing the experimental damage profiles with those simulated using SRIM-2000. The critical amorphization doses generally increase as the A-site cation changes from Sm3+ to Er3+, suggesting that the radiation resistance of titanate pyrochlores increases with the decreasing ionic radius of A-site cations.
Surface Modification Techniques
Published in S Santhosh Kumar, Somashekhar S. Hiremath, Role of Surface Modification on Bacterial Adhesion of Bio-Implant Materials, 2020
S Santhosh Kumar, Somashekhar S. Hiremath
Alkali treatment: Alkali treatment (e.g., NaOH treatment) is a popular chemical surface treatment method. Titanium nanostructures with a sodium titanate gel layer outward from the surface have been seen after NaOH treatment. The formation of the gel-like layer over the implant surface allows for HA deposition. H2O produces a titania gel layer. This behaviour has also been seen with other metals such as zirconium and aluminium. Alkali treatment results in the growth of a nanostructured and bioactive sodium titanate layer on implant surfaces (Rasouli et al., 2018).
Physics of Ultrasound
Published in Marvin C. Ziskin, Peter A. Lewin, Ultrasonic Exposimetry, 2020
As a general purpose ultrasonic generator, PZT-4 is an excellent choice of ferroelectric ceramic. Numerous other formulations of lead zirconate titanate exist, however, containing proprietary quantities of other oxides. Thus, PZT-5A has a lower Q-factor and is more suitable for short-pulse operation. Such a material is usually chosen when the same transducer is to be used as transmitter and receiver, as in a pulse-echo system.
Antibacterial properties of silver nanoparticles grown in situ and anchored to titanium dioxide nanotubes on titanium implant against Staphylococcus aureus
Published in Nanotoxicology, 2020
Urvashi F. Gunputh, Huirong Le, Kiruthika Lawton, Alexandros Besinis, Christopher Tredwin, Richard D. Handy
The synthesis of the composite coatings started with TiO2-NTs followed by the addition of Ag NPs and last nHA. To start with, the self-assembly of the TiO2-NTs on to titanium alloy discs was conducted using an anodisation process as previously optimised (Danookdharree, Le, and Tredwin 2015). Briefly, this was a 1-h electrochemical reaction in a mixture of 1mol/L NH4HPO4 and 0.5wt% NH4F (0.5g of NH4F in 100mL of ammonia solution) at 20V. All the coated discs were then annealed at 350°C for 2h in a furnace to achieve the anatase phase (Carbolite RWF 1200, Carbolite Engineering Services, Hope Valley, UK). The TiO2-NTs were then functionalised by treating them with 2mol/L NaOH at 50°C for 2min (Parcharoen et al. 2014). This resulted in the formation of sodium titanate (Na2Ti3O7) which is a reactive surface for the next steps in the synthesis of the composite material.
How to control fluorescent labeling of metal oxide nanoparticles for artefact-free live cell microscopy
Published in Nanotoxicology, 2021
Boštjan Kokot, Hana Kokot, Polona Umek, Katarina Petra van Midden, Stane Pajk, Maja Garvas, Christian Eggeling, Tilen Koklič, Iztok Urbančič, Janez Štrancar
TiO2 nanotubes were synthesized in-house using the method, described elsewhere (Umek et al. 2005; Garvas et al. 2015). Synthesis of the anatase TiO2 nanotubes with a diameter of 10 nm, mean length of 200 nm and a BET surface of 150 m2 g−1 proceeds in several stages:1). Synthesis of sodium titanate nanotubes (NaTiNTs);
Evaluation of toxicity of halloysite nanotubes and multi-walled carbon nanotubes to endothelial cells in vitro and blood vessels in vivo
Published in Nanotoxicology, 2020
Bihan Wu, Mengdie Jiang, Xuewu Liu, Chaobo Huang, Zhipeng Gu, Yi Cao
The results from this study suggested that MWCNTs were more toxic to ECs and blood vessels compared with HNTs at the same mass concentrations. Previous studies already investigated the possible roles of physicochemical properties in determining the toxicity of NMs to vascular systems. For example, we recently showed that increasing the lengths (Long et al. 2017) or decreasing the diameters (Zhao et al. 2019) could increase the toxicity of MWCNTs to HUVECs. Under in vivo conditions, Cao et al. found that longer MWCNTs were more potent than shorter ones to induce inflammation and plaque progression in atherosclerotic mice (Cao, Jacobsen, et al. 2014). Regarding the morphologies, it has been shown that the toxicity of carbon black NPs to vascular systems was generally less pronounced or even absent compared with CNTs at the same mass concentrations, which indicated a crucial role of tubular structures in the toxicity of CNTs (Cao, Jacobsen, et al. 2014; Cao, Roursgaard, et al. 2014; Long et al. 2017; Walker et al. 2009). Moreover, we recently showed that titanate NTs more effectively induced EC activation compared with TiO2 NPs (Li et al. 2020). Therefore, we suggested that the relatively higher toxicity of MWCNTs compared with HNTs could be at least partially due to that MWCNTs are relatively longer in length and smaller in diameter (Figure 1). MWCNTs with a relatively longer length and smaller diameter have a correspondingly larger surface area (Table 1), which can increase their interactions with cells and consequently lead to higher toxicity of NMs. Some studies also suggested that NMs could induce toxicity to vascular systems through the release of excessive metal ions due to the solubility of NMs and/or iron contaminations (Cao, Gong, et al. 2017). However, HNTs and MWCNTs used in this study are based on insoluble materials and only MWCNTs contain a low level of iron contaminations (Supplemental Table S2). Therefore, it is unlikely that the higher toxicity of MWCNTs is contributed by iron impurities. Based on the toxicological data reported in this study, HNTs are probably better nanocarriers as HNTs could be internalized in relatively large amounts but induced less toxic effects compared with MWCNTs. To further reduce the toxicity, HNTs could be surface-functionalized to improve the targeting and thus reduce the overall concentrations of NMs needed (Gao et al. 2019; Saleem, Wang, and Chen 2018).