Design and characterization of Fe(II) complexes with tetradentate ligands exhibiting spin-crossover near room temperature.

Construction of spin-crossover (SCO) materials is very appealing for applications such as molecular switches and information storage. This study focuses on the design of Fe(II) complexes using N,N'-bis(2-pyridinylmethyl)-1,2-ethanediamine-based ligands with an N4 structure for SCO material development. By incorporating para-substituted benzene groups into the ligand's pyridine moiety, two polymorphs, α and ß, were obtained, both exhibiting SCO activity. Notably, the ß polymorph displayed a spin crossover temperature of 270 K, which is approaching room temperature. Structural analyses were conducted to compare the differences between the polymorphs, along with a literature review of related complexes, providing insights into the characteristics of SCO behavior.

Influence of acetate-to-butyrate ratio on carbon chain elongation in anaerobic fermentation.

This study investigated the effect of electron acceptor (EA) distribution (acetate to butyrate ratio) on the carbon chain elongation (CCE) process. The results showed that the higher content of butyrate in the initial material led to the higher production of caproate. The maximum production of caproate was 3.74 ± 0.30 g·L-1, which was obtained when only butyrate was added as EA. Little caproate but much butyrate was produced where only acetate was added as EA. This indicated that CCE bacteria preferentially selected acetate as the EA to produce butyrate, and butyrate could be selected as EA to produce caproate only when the acetate content was much lower than butyrate. Unclassified_f_Dysgonomonadaceae, Massilibacterium, and Seramator were the predominant bacteria. Functional enzyme analysis showed that high butyrate content strengthened the fatty acid biosynthesis pathway and reverse ß-oxidization pathway. The findings showed the importance of butyrate in CCE for caproate production.

Inactivation of E. coli, S. aureus, and Bacteriophages in Biofilms by Humidified Air Plasma.

In this study, humidified air dielectric barrier discharge (DBD) plasma was used to inactivate Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and bacteriophages in biofilms containing DNA, NaCl, carbohydrates, and proteins. The humidified DBD plasma was very effective in the inactivation of microbes in the (≤1.0 µm) biofilms. The number of surviving E. coli, S. aureus, and bacteriophages in the biofilms was strongly dependent on the constituent and thickness of the biofilms and was greatly reduced when the plasma treatment time increased from 5 s to 150 s. Our analysis shows that the UV irradiation was not responsible for the inactivation of microbes in biofilms. The short-lived RONS generated in the humidified air DBD plasma were not directly involved in the inactivation process; however, they recombined or reacted with other species to generate the long-lived RONS. Long-lived RONS diffused into the biofilms to generate very active species, such as ONOOH and OH. This study indicates that the geminated NO2 and OH pair formed due to the homolysis of ONOOH can cause the synergistic oxidation of various organic molecules in the aqueous solution. Proteins in the biofilm were highly resistant to the inactivation of microbes in biofilms, which is presumably due to the existence of the unstable functional groups in the proteins. The unsaturated fatty acids, cysteine-rich proteins, and sulfur-methyl thioether groups in the proteins were easily oxidized by the geminated NO2 and OH pair.

Characterization of lithium zinc titanate doped with metal ions as anode materials for lithium ion batteries.

With the aim of improving the ionic and electronic conductivities of Li2ZnTi3O8 for high performance lithium ion battery applications, Li2Zn0.9M0.1Ti3O8 (M = Li+, Cu2+, Al3+, Ti4+, Nb5+, Mo6+) compounds are successfully fabricated using facile high temperature calcination at 800 °C. Physical characterization and lithium ion reversible storage demonstrate that Zn-site substitution by multivalent metal ions is beneficial for improving the migration rate of ions and electrons of Li2ZnTi3O8. X-ray diffraction analysis and scanning electron microscopy reveal that the crystal structure and microscopic morphology of bare Li2ZnTi3O8 do not change by introducing a small amount of foreign metal ions. As a result, Li2Zn0.9Nb0.1Ti3O8 retains a reversible capacity as high as 198 mA h g-1 at the end of the 500th cycle among all samples. Even when cycled at high temperatures, Li2Zn0.9Nb0.1Ti3O8 still maintains excellent reversible discharge capacities of 210 mA h g-1 and 196 mA h g-1 at 1000 mA g-1 for the 100th cycle at 50 °C and 60 °C, respectively. All the conclusions indicate that Li2Zn0.9Nb0.1Ti3O8 is a high-performance anode material for large-scale energy storage devices.