ORCID Profile
0000-0002-1519-6830
Current Organisation
Wuhan University of Technology
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 11-2011
DOI: 10.1016/J.BIOMATERIALS.2011.07.080
Abstract: Enzymatic degradation is a major feature of polyester implants in vivo. An in vitro experimental protocol that can simulate and predict the in vivo enzymatic degradation kinetics of implants is of importance not only to our understanding of the scientific issue, but also to the well-being of animals. In this study, we explored the enzymatic degradation of PGS-based materials in vitro, in tissue culture medium or a buffer solution at the pH optima and under static or cyclic mechanical-loading conditions, in the presence of defined concentrations of an esterase. Surprisingly, it was found that the in vitro enzymatic degradation rates of the PGS-based materials were higher in the tissue culture medium than in the buffered solution at the optimum pH 8. The in vitro enzymatic degradation rate of PGS-based biomaterials crosslinked at 125°C for 2 days was approximately 0.6-0.9 mm/month in tissue culture medium, which falls within the range of in vivo degradation rates (0.2-1.5mm/month) of PGS crosslinked at similar conditions. Enzymatic degradation was also further enhanced in relation to mechanical deformation. Hence, in vitro enzymatic degradation of PGS materials conducted in tissue culture medium under appropriate enzymatic conditions can quantitatively capture the features of in vivo degradation of PGS-based materials and can be used to indicate effective strategies for tuning the degradation rates of this material system prior to animal model testing.
Publisher: Beilstein Institut
Date: 25-01-2019
DOI: 10.3762/BJNANO.10.27
Abstract: Developing a facile and environmentally friendly approach to the synthesis of nanostructured Ni(OH) 2 electrodes for high-performance supercapacitor applications is a great challenge. In this work, we report an extremely simple route to prepare a Ni(OH) 2 nanopetals network by immersing Ni nanofoam in water. A binder-free composite electrode, consisting of Ni(OH) 2 nanopetals network, Ni nanofoam interlayer and Ni-based metallic glass matrix (Ni(OH) 2 /Ni-NF/MG) with sandwich structure and good flexibility, was designed and finally achieved. Microstructure and morphology of the Ni(OH) 2 nanopetals were characterized. It is found that the Ni(OH) 2 nanopetals interweave with each other and grow vertically on the surface of Ni nanofoam to form an “ion reservoir”, which facilitates the ion diffusion in the electrode reaction. Electrochemical measurements show that the Ni(OH) 2 /Ni-NF/MG electrode, after immersion in water for seven days, reveals a high volumetric capacitance of 966.4 F/cm 3 at a current density of 0.5 A/cm 3 . The electrode immersed for five days exhibits an excellent cycling stability (83.7% of the initial capacity after 3000 cycles at a current density of 1 A/cm 3 ). Furthermore, symmetric supercapacitor (SC) devices were assembled using ribbons immersed for seven days and showed a maximum volumetric energy density of ca. 32.7 mWh/cm 3 at a power density of 0.8 W/cm 3 , and of 13.7 mWh/cm 3 when the power density was increased to 2 W/cm 3 . The fully charged SC devices could light up a red LED. The work provides a new idea for the synthesis of nanostructured Ni(OH) 2 by a simple approach and ultra-low cost, which largely extends the prospect of commercial application in flexible or wearable devices.
Publisher: MDPI AG
Date: 03-09-2019
DOI: 10.3390/APP9173623
Abstract: Silicon micropillars with tunable sizes are successfully fabricated on copper foils by using nanosecond-pulsed laser irradiation and then used as anodes for lithium-ion batteries. The size of the silicon micropillars is manipulated by using different slurry layer thicknesses ranging from a few microns to tens of microns. The effects of the pillar size on electrochemical properties are thoroughly investigated. The smaller the pillars, the better the electrochemical performance. A capacity of 1647 mAh g−1 at 0.1 C current rate is achieved in the anode with the smallest pillars, with 1215, 892, and 582 mAh g−1 at 0.2, 0.5, and 1.0 C, respectively. Although a significant difference in discharge capacity is observed in the early period of cycling among micropillars of different sizes, this discrepancy becomes smaller as a function of the cycle number. Morphological studies reveal that the expansion of micropillars occurred during long-term cycling, which finally led to the formation of island-like structures. Also, the formation of a solid electrolyte interphase film obstructs Li+ diffusion into Si for lithiation, resulting in capacity decay. This study demonstrates the importance of minimizing the pillar size and optimizing the pillar density during anode fabrication.
Publisher: Elsevier BV
Date: 08-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2RA20113E
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.ACTBIO.2016.07.008
Abstract: Titanium alloys are popular metallic implant materials for use in total hip replacements. Although, α+β titanium alloys such as Ti-6Al-4V have been the most commonly used alloys, the high Young's modulus (∼110GPa) leads to an undesirable stress shielding effect. An alternative is to use β titanium alloys that exhibit a significantly lower Young's modulus (∼70GPa). Femoral stems made of a β titanium alloy known as TMZF (Ti-12Mo-6Zr-2Fe (wt.%)) have been used as part of modular hip replacements since the early 2000's but these were recalled in 2011 by the US Food & Drug Administration (FDA) due to unacceptable levels of 'wear debris'. The wear was caused by small relative movement of the stem and neck at the junction where they fit together in the modular hip replacement design. In this study, the corrosion and wear properties of the TMZF alloy were investigated in simulated body fluid to identify the reason for the wear debris generation. Ti64 was used as a control for comparison. It is shown that the interaction between the surfaces of Ti64 and TMZF with simulated body fluid is very similar, both from the point of view of the products formed and the kinetics of the reaction. The dry wear behaviour of TMZF is also close to that of Ti64 and consistent with expectations based on Archard's law for abrasive wear. However, wear of Ti64 and TMZF in simulated body fluid show contrasting behaviours. A type of time-dependent wear test is used to examine the synergy between corrosion and wear of TMZF and Ti64. It is shown that the wear of TMZF accelerated rapidly in SBF whereas that of Ti64 is reduced. The critical role of the strain hardening capacity of the two materials and its role in helping the surface resist abrasion by hydroxyapatite particles formed as a result of the reaction with the SBF is discussed and recommendations are made for modifications that could be made to the TMZF alloy to improve the corrosion-wear response. TMZF is a low modulus β-Ti alloy that has been used as the femoral stem in the Stryker modular design total hip replacement. It went into service in the early 2000's but was recalled by the FDA in 2011 due to unacceptable levels of wear debris released in the body which led to adverse physiological reactions. A large number of these implants remain in patients today. In this contribution, we investigate the corrosion (interaction of the alloy with simulated body fluid (SBF)), dry wear and then corrosion-wear in SBF to identify the origin of the unacceptable levels of wear that led to the FDA recall of this material. We use Ti-6Al-4V as a control and demonstrate that the reaction between Ti64 and TMZF with SBF is very similar in terms of both products formed and kinetics. We also show that the dry wear behaviour of TMZF is very similar to that of Ti64 and exactly as should be expected for the hardness of this material. However, the wear behaviours of TMZF and Ti64 are completed different in SBF and wear of TMZF is significantly accelerated in SBF. A type of time-dependent wear test is used to demonstrate the synergy between corrosion and wear and the key role of the strain hardening capacity (or lack thereof in the case of β-Ti) is discussed.
Publisher: Elsevier BV
Date: 06-2020
No related grants have been discovered for Xueyuan Yang.