Voltammetric investigations on the relative deactivation of boron-doped diamond, glassy carbon and platinum electrodes during the anodic oxidation of substituted phenols in room temperature ionic liquids

Effect of Alkyl Chain Length on the Magnitude of Dynamically Correlated Molecules and Dynamical Crossover in Alkyltriethylammonium-Based Ionic Liquids

This study explores the impact of alkyl chain length on dynamic heterogeneity and dynamic crossover in alkyltriethylammonium-based ionic liquids ([TEA-R][TFSI]) with varying alkyl chain lengths (R = C6, C8, and C10). Using differential scanning calorimetry and broadband dielectric spectroscopy, we observed that these ionic liquids are excellent glassformers with notable ionic conductivity at room temperature. Furthermore, the number of dynamically correlated molecules at the glass transition temperature, reflecting the dynamic heterogeneity, is exceptionally small for TEA-R ILs and becomes more reduced with longer alkyl chains. Moreover, the temperature dependence of conductivity requires two Vogel-Fulcher-Tammann equations with distinct sets of fitting parameters for an accurate description. The crossover temperature Tb, indicating the transition to complex dynamics, increases with the alkyl chain length.

In Vitro and In Vivo Metabolic Activation and Hepatotoxicity of Environmental Pollutant 2,6-Dimethylphenol

2,6-Dimethylphenol (2,6-DMP) is an environmental pollutant found in industrial wastewater. Exposure to 2,6-DMP is of increasing concern as it endangered reportedly some aquatic animals. In this study, we investigated the metabolic activation and hepatotoxicity of 2,6-DMP. 2,6-DMP was metabolized to an o-quinone methide intermediate in vitro and in vivo. The electrophilic metabolite was reactive to the sulfhydryl groups of glutathione, N-acetyl cysteine, and cysteine. NADPH was required for the formation of the reactive metabolite. The quinone methide intermediate reacted with cysteine residues to form hepatic protein adduction. A single dose of 2,6-DMP induced marked elevation of serum ALT and AST in mice. Both the protein adduction and hepatotoxicity of 2,6-DMP showed dose dependency.

Influence of dimethylphenol isomers on electrochemical degradation: Kinetics, intermediates, and DFT calculation

Dimethylphenol isomers (DMP) pose a great threat to the environment, and the electrooxidation (EO) process proves to be an extraordinarily effective method to degrade DMP. However, the EO performance is affected by the molecular structure of DMP and the adopted experimental parameters. In this study, the effects of 2,4-DMP and 2,6-DMP on the working potential, limiting current density (J_lim), and pH were systematically analysed, with Ti-mesh plates used as the cathode and Ti/PbO₂ as the anode. The peak potentials of 2,4-DMP and 2,6-DMP were determined to be 0.83 V and 0.77 V by cyclic voltammetry, with J_lim were 2.5 mA·cm^-2 and 2.0 mA·cm^-2, respectively. The whole process exhibited pseudo-first-order kinetics, and the kinetic constants (K) for the degradation of 2,4-DMP and 2,6-DMP were determined to be 0.0041 min^-1 and 0.0150 min^-1, respectively. Additionally, the optimal initial pH value for 2,4-DMP and 2,6-DMP was 5.0, where the highest hydroxyl (OH) radical density, as determined by the electron spin technique (ESR), was achieved at a higher current density. Comparatively, the OH radical density in the 2,6-DMP solution was lower than that in 2,4-DMP. In situ Fourier infrared (FT-IR) spectroscopy, GC-MS, and density functional theory (DFT) were employed to explore three possible degradation pathways. The main intermediates for 2,4-DMP degradation were determined to be quinone and ether, while that for 2,6-DMP degradation was quinone. According to the results of this study, the molecular structure (different methyl group positions on the benzene ring) has a great influence on the EO process.

Influence of Alkyl Chain Length on Thermal Properties, Structure, and Self-Diffusion Coefficients of Alkyltriethylammonium-Based Ionic Liquids

The application of ionic liquids (ILs) has grown enormously, from their use as simple solvents, catalysts, media in separation science, or electrolytes to that as task-specific, tunable molecular machines with appropriate properties. A thorough understanding of these properties and structure-property relationships is needed to fully exploit their potential, open new directions in IL-based research and, finally, properly implement the appropriate applications. In this work, we investigated the structure-properties relationships of a series of alkyltriethylammonium bis(trifluoromethanesulfonyl)imide [TEA-R][TFSI] ionic liquids in relation to their thermal behavior, structure organization, and self-diffusion coefficients in the bulk state using DSC, FT-IR, SAXS, and NMR diffusometry techniques. The phase transition temperatures were determined, indicating alkyl chain dependency. Fourier-transformed infrared spectroscopy studies revealed the structuration of the ionic liquids along with alkyl chain elongation. SAXS experiments clearly demonstrated the existence of polar/non-polar domains. The alkyl chain length influenced the expansion of the non-polar domains, leading to the expansion between cation heads in polar regions of the structured IL. 1H NMR self-diffusion coefficients indicated that alkyl chain elongation generally caused the lowering of the self-diffusion coefficients. Moreover, we show that the diffusion of anions and cations of ILs is similar, even though they vary in their size.

Enhanced electrocatalytic activity of nano-TiN composited Ti/Sb–SnO2 electrode fabricated by pulse electrodeposition for methylene blue decolorization

The Sb-doped SnO₂ electrode is modified by TiN nanoparticles and has higher stability and significantly enhanced electrochemical decolorization activity.