Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl2O4 Ceramics

Klym, Halyna; Karbovnyk, Ivan; Piskunov, Sergei; Попов, А. И.

doi:10.3390/nano11123373

Cited by 43 publications

(21 citation statements)

References 67 publications

(95 reference statements)

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“…The good porosity is helpful for cell culture and blood vessel growth and is also an important measure of bone scaffolds [ 41 ]. Figure 13 showed the porosity of scaffold samples with different internal structures.…”

Section: Resultsmentioning

confidence: 99%

3D Printing and Performance Study of Porous Artificial Bone Based on HA-ZrO2-PVA Composites

Bie¹,

Chen

Shan

et al. 2023

Materials

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An ideal artificial bone implant should have similar mechanical properties and biocompatibility to natural bone, as well as an internal structure that facilitates stomatal penetration. In this work, 3D printing was used to fabricate and investigate artificial bone composites based on HA-ZrO2-PVA. The composites were proportionally configured using zirconia (ZrO2), hydroxyapatite (HA) and polyvinyl alcohol (PVA), where the ZrO2 played a toughening role and PVA solution served as a binder. In order to obtain the optimal 3D printing process parameters for the composites, a theoretical model of the extrusion process of the composites was first established, followed by the optimization of various parameters including the spray head internal diameter, extrusion pressure, extrusion speed, and extrusion line width. The results showed that, at the optimum parameters of a spray head diameter of 0.2 mm, extrusion pressure values ranging from 1–3 bar, a line spacing of 0.8–1.5 mm, and a spray head displacement range of 8–10 mm/s, a better structure of biological bone scaffolds could be obtained. The mechanical tests performed on the scaffolds showed that the elastic modulus of the artificial bone scaffolds reached about 174 MPa, which fulfilled the biomechanical requirements of human bone. According to scanning electron microscope observation of the scaffold sample, the porosity of the scaffold sample was close to 65%, which can well promote the growth of chondrocytes and angiogenesis. In addition, c5.18 chondrocytes were used to verify the biocompatibility of the composite materials, and the cell proliferation was increased by 100% when compared with that of the control group. The results showed that the composite has good biocompatibility.

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Section: Resultsmentioning

confidence: 99%

3D Printing and Performance Study of Porous Artificial Bone Based on HA-ZrO2-PVA Composites

Bie¹,

Chen

Shan

et al. 2023

Materials

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“…This model does not consider the change of porosity and its influence on the material during the loading process. For further research, please refer to Reference [ 35 ].…”

Section: Resultsmentioning

confidence: 99%

Phase-Field Simulation of Temperature-Dependent Thermal Shock Fracture of Al2O3/ZrO2 Multilayer Ceramics with Phase Transition Residual Stress

Pang

et al. 2023

Materials

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Compared with single-phase ceramics, the thermal shock crack propagation mechanism of multiphase layered ceramics is more complex. There is no experimental method and theoretical framework that can fully reveal the thermal shock damage mechanism of ceramic materials. Therefore, a multiphase phase-field fracture model including the temperature dependence of material for thermal shock-induced fracture of multilayer ceramics is established. In this study, the effects of residual stress on the crack propagation of ATZ (Al2O3-5%tZrO2)/AMZ (Al2O3-30%mZrO2) layered ceramics with different layer thickness ratios, layers, and initial temperatures under bending and thermal shock were investigated. Simulation results of the fracture phase field under four-point bending are in good agreement with the experimental results, and the crack propagation shows a step shape, which verifies the effectiveness of the proposed method. With constant thickness, high-strength compressive stress positively changes with the layer thickness ratio, which contributes to crack deflection. The cracks of the ceramic material under thermal shock have hierarchy and regularity. When the layer thickness ratio is constant, the compressive residual stress decreases with the increase in the layer number, and the degree of thermal shock crack deflection decreases.

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“…However, the pore structures of titanium oxides that have been reported still need a lot of improvements. Additionally, the pore dynamics of titanium oxides may be studied in detail by positron annihilation lifetime spectroscopy (PALS) [ 31 ].…”

Section: Introductionmentioning

confidence: 99%

Fe Ions-Doped TiO2 Aerogels as Catalysts of Oxygen Reduction Reactions in Alkaline Solutions

et al. 2022

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Aerogels have interconnected networks and preeminent pore structures. When used as the catalysts for oxygen reduction reaction (ORR), they can facilitate the mass transfer and expose more active sites. Here, we synthesized the Fe-doped titanium oxide-based aerogels (TA/Fes) by the sol–gel method combined with thermal treatment. The specific surface areas of the TA/Fes ranged from 475 to 774 m2·g−1, and the pore volumes varied from 0.96 to 1.72 cm3·g−1. The doping effect of the Fe ions and the oxygen vacancies in anatase enhance the electrical conductivity, leading to the low Rct (313.3–828.2Ω). All samples showed excellent stability (2.0–4.5 mV) and 4e− pathway. The limiting current density of TA/Fe3 reached 5.34 mA·cm−2, which was comparable to that of commercial Pt/C. The preparation method is inspiring and the as-prepared aerogel catalysts have potential in promoting the scale of fuel cells.

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Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl2O4 Ceramics

Cited by 43 publications

References 67 publications

3D Printing and Performance Study of Porous Artificial Bone Based on HA-ZrO2-PVA Composites

3D Printing and Performance Study of Porous Artificial Bone Based on HA-ZrO2-PVA Composites

Phase-Field Simulation of Temperature-Dependent Thermal Shock Fracture of Al2O3/ZrO2 Multilayer Ceramics with Phase Transition Residual Stress

Fe Ions-Doped TiO2 Aerogels as Catalysts of Oxygen Reduction Reactions in Alkaline Solutions

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