Ionic liquids (ILs) are the safest solvent in various high-temperature applications due to their non-flammable properties. In order to obtain their thermal stability properties, thermogravimetric analysis (TGA) is extensively used to analyze the kinetics of the thermal decomposition process. This review summarizes the different kinetics analysis methods and finds the isoconversional methods are superior to the Arrhenius methods in calculating the activation energy, and two tools—the compensation effect and master plots—are suggested for the calculation of the pre-exponential factor. With both parameters, the maximum operating temperature (MOT) can be calculated to predict the thermal stability in long-term runnings. The collection of thermal stability data of ILs with divergent cations and anions shows the structure of cations such as alkyl side chains, functional groups, and alkyl substituents will affect the thermal stability, but their influence is less than that of anions. To develop ILs with superior thermal stability, dicationic ILs (DILs) are recommended, and typically, [C4(MIM)2][NTf2]2 has a decomposition temperature as high as 468.1 °C. For the convenience of application, thermal stability on the decomposition temperature and thermal decomposition activation energy of 130 ILs are summarized at the end of this manuscript.

No abstract

Six novel dicationic imizadolium‐based tetrafluoroborate ionic liquids were synthesized, with four of which contained hydroxyl groups. Their chemical structures were identified by FTIR and 1H NMR, and their onset decomposition temperatures (Tonset) were measured by thermogravimetric analysis (TGA). For investigating the hydrothermal stability, all DILs were mixed with water and heated for 1, 5, and 9 hours to 240 °C in an airtight kettle.The results show that DILs with hydroxyls have a higher Tonset but they exhibit evident changes in chemical structures after heating with water for 9 hours. The conflicts between Tonset and long‐term stability tests is ascribed to the reason that water forms new hydrogen bonds with hydroxyls and therefore weakens the intramolecular interaction between the cation and anion.

No abstract

The COVID-19 had a tremdeous effect on the stock market all over the world. US and China are the major capital markets worldwide. They have obviously been touched during the past three years by the COVID-19 epidemic. The stock markets of the two nations are very similar and very different at the same time. Both positive and negative emotions have emerged during the pandemic, at the national level, among companies and among individual investors. The rapid recovery from the recession is also on the table. In this paper, the impact of the COVID-19 pandemic is discussed with the analysis of two stock markets’ similarities. Additionally, the variations are contrasted and advice on asset management is given to investors in the post-pandemic era. Fama-French model is a mature and effective method to analyze the stock market in the relevant study, and its precision can be accurately used to analyze the stock market.