Low temperature biosynthesis of Li2O-MgO-P2O5-TiO2 nanocrystalline glass with mesoporous structure exhibiting fast lithium ion conduction

New Insights Into Microbial Induced Calcium Carbonate Precipitation Using Saccharomyces cerevisiae

Saccharomyces cerevisiae plays an important role in the mineralization of many metal ions, but it is unclear whether this fungus is involved in the mineralization of calcium carbonate. In this study, S. cerevisiae was cultured under various conditions to explore its ability to perform microbially induced calcium carbonate precipitation (MICP). Organic acids, yeast extract, and low-carbon conditions were the factors influencing the biomineralization of calcium carbonate caused by S. cerevisiae, and biomolecules secreted by the fungus under different conditions could change the morphology, size, and crystal form of the biosynthesized mineral. In addition, transcriptome analysis showed that the oxidation of organic acids enhanced the respiration process of yeast. This implied that S. cerevisiae played a role in the formation of calcium carbonate through the mechanism of creating an alkaline environment by the respiratory metabolism of organic acids, which could provide sufficient dissolved inorganic carbon for calcium carbonate formation. These results provide new insights into the role of S. cerevisiae in biomineralization and extend the potential applications of this fungus in the future.

Investigating the Intermediate Water Feature of Hydrated Titanium Containing Bioactive Glass

Intermediate water (IW) in hydrated bioactive glasses remains uninvestigated. We obtained titanium (Ti)-containing bioactive glasses (BGTs) (Ti at 5%, 7.5% and 10% of the glass system) using the sol-gel technique. Their thermal, physicochemical, and morphological properties, before and after Ti-doping, were analysed using DTA, XRD, FTIR, TEM, and SEM accessorised with EDAX, and size distribution and zeta potential surface charges were determined using a NanoZetasizer. The IW in hydrated BGTs was investigated by cooling and heating runs of DSC measurements. Moreover, the mode of death in an osteosarcoma cell line (MG63) was evaluated at different times of exposure to BGT discs. Ti doping had no remarkable effect on the thermal, physicochemical, and morphological properties of BGTs. However, the morphology, size, and charges of BGT nano-powders were slightly changed after inclusion of Ti compared with those of BGT0; for example, the particle size increased with increasing Ti content (from 4-5 to 7-28 nm). The IW content was enhanced in the presence of Ti. The mode of cell death revealed the effect of IW content on the proliferation of cells exposed to BGTs. These findings should help improve the biocompatibility of inorganic biomaterials.

The Surface Coating of Commercial LiFePO4 by Utilizing ZIF-8 for High Electrochemical Performance Lithium Ion Battery

The requirement of energy-storage equipment needs to develop the lithium ion battery (LIB) with high electrochemical performance. The surface modification of commercial LiFePO₄ (LFP) by utilizing zeolitic imidazolate frameworks-8 (ZIF-8) offers new possibilities for commercial LFP with high electrochemical performances. In this work, the carbonized ZIF-8 (C_ZIF-8) was coated on the surface of LFP particles by the in situ growth and carbonization of ZIF-8. Transmission electron microscopy indicates that there is an approximate 10 nm coating layer with metal zinc and graphite-like carbon on the surface of LFP/C_ZIF-8 sample. The N₂ adsorption and desorption isotherm suggests that the coating layer has uniform and simple connecting mesopores. As cathode material, LFP/C_ZIF-8 cathode-active material delivers a discharge specific capacity of 159.3 mAh g^-1 at 0.1C and a discharge specific energy of 141.7 mWh g^-1 after 200 cycles at 5.0C (the retention rate is approximate 99%). These results are attributed to the synergy improvement of the conductivity, the lithium ion diffusion coefficient, and the degree of freedom for volume change of LFP/C_ZIF-8 cathode. This work will contribute to the improvement of the cathode materials of commercial LIB.