As a kind of bioactive component in the rhizome of natural plant Curcuma longa L. (turmeric), curcumin is almost insoluble in water at neutral and acidic pH, which limits its further utilization and development. At the same time, traditional extraction and separation processes typically require the use of a large number of organic solvents. Ionic liquids (ILs) are organic molten salts with melting points below 100 °C. When an ionic liquid exists in a liquid state at or near room temperature, it is referred to as a room-temperature ionic liquid (RTIL). They have a temperature range, good physical and chemical stability, and good structural designability. They have a strong solubilization enhancement effect for many organic compounds. This study first explored the molecular forms of curcumin in ionic liquid aqueous solutions and the intermolecular interactions between curcumin and ionic liquids using spectral analysis and computational chemistry methods; furthermore, using an ionic liquid aqueous solution as an extraction agent, curcumin-like substances (curcuminoids) were extracted from turmeric powders under ultrasound assisted conditions, revealing the relationship between the structure of the ionic liquid and the extraction efficiency. After that, a kinetic study was conducted for the extraction of curcuminoids from turmeric powders, using second-order kinetics fitting to obtain the rate constant and initial extraction rate during the extraction process. Finally, the comparison with a ComplexGAPI tool and antioxidant experiment was performed on the extraction by using ionic liquids and traditional solvent. The full results can provide reference for the design of IL extractants and their application for natural products.

Some active pharmaceutical ingredients (APIs) and excipients can form deep eutectic solvents (DESs), which will lead to severe defects in solid preparations. This work first prepared related typical DESs by mixing APIs and excipients from marketable drugs. Then two different types of the binary eutectic mixtures were investigated, which were composed of menthol (HBD) and citric acid (HBA) (ME/CA) as well as phenyl salicylate (HBA) and benzoic acid (HBD) (Salol/BA). These binary mixtrures were applied to investigate their possible effects on capsules and tablets, which could be liquefaction or the stickiness of the solid formulations. The comprehensive characterizations and studies on phase behaviors of the binary mixtures were carried out, and the spectral analysis confirmed the formation of the eutectic liquids from individual components. Furthermore, the binary mixtures have increased the tablet strength when increasing the compression force, leading to the stickiness of powders during pressing. Moreover, the capsules were softened by the existence of DESs. After morphological observation and quantitative analysis, the corresponding suggestions and countermeasures were provided in the conclusions.

2-Methyl-3-butenenitrile, a key intermediate in the industrial production of Nylon-66, is often accompanied by two other by-products, 2-methyl-2-butenenitrile and 2-pentenenitrile, which have been proven to affect the production yield and quality of Nylon-66. Pure 2-pentenenitrile is a commercial synthetic intermediate for many chemical products and bioactive substances. As important foundational data for designing large-scale separation and purification processes for these three compounds are lacking, the saturated vapor pressure of pure 2-pentenenitrile was measured over the temperature range 298.5 K to 401.4 K, and vapor–liquid equilibrium (VLE) data for the binary systems (2-methyl-3-butenenitrile + 2-pentenenitrile, 2-methyl-2-butenenitrile + 2-pentenenitrile) were determined at pressures of 50.0 kPa and 100.0 kPa. In order to better utilize these experimental data for the design of large-scale separation distillation processes, the experimental saturated vapor pressure data of pure 2-pentenenitrile were well correlated using the Antoine equation, yielding an average relative deviation of 0.92%. For all binary systems, the thermodynamic consistency of the VLE results was verified using both the point test and the direct test. The binary VLE data were correlated with the Wilson and NRTL activity coefficient models, and the corresponding model parameters were obtained by regression, which can help to obtain complete data in the whole mole fraction range for industrial separation design.

At present, ionic liquids (ILs) are increasingly being used to extract natural products as green solvents, but their residues can lead to risks in terms of further use for the extracted herbal materials. Therefore, it is necessary to remove them with simple and effective methods. For example, after the toxic anthraquinones in Polygonum multiflorum are removed by extraction with the IL of [C₄Bim][PTSA], it needs to be recovered and reused, and the useful stilbene glycosides should not suffer from obvious loss as they are the main functional components. In this study, an ultrasonic method with n-propanol was used to remove the residual [C₄Bim][PTSA] in the solid powders of Polygonum multiflorum that had been extracted for anthraquinones. After single-factor optimization, the removal conditions were as follows: the removal temperature was 303.15 K, the solid–liquid ratio was 1:200 (w (1 g):v (200 mL)), the ultrasonic time was 40 min, and there were four operations. Under these conditions, ILs could be completely removed with almost no loss of stilbene glycosides in solid powders. After that, the IL in the extracting solution and scrubbing solution was recovered by the back-extraction method, and an IL with high purity could be obtained for reuse. The total recovery efficiency of the IL reached more than 98%. Then gas chromatography (GC) was conducted for the determination of residual ethanol and n-propanol in the solid powders of Polygonum multiflorum, which could be used to quickly detect the contents of two organic solvents within three minutes. Besides that, the method could also be applied to the determination of residual organic solvents in the raw materials of Polygonum multiflorum, and the results showed that the residue of ethanol and n-propanol in the solid powders were in accordance with the general provisions of the current Chinese Pharmacopoeia. According to the developed procedures and optimized conditions, the recovered IL could be reused in five runs at least. General applicability and greenness assessment for the developed process also proved that it is an ideal method, which has potential in large-scale application.

As a new sustainable catalyst and green solvent, ionic liquid has important applications in catalytic reduction. In this study, four quinuclidinol-based quaternary ammonium ionic liquids (ILs)were at first prepared using simple procedures, and then they were used as catalyst for acetophenone reduction. The main catalytic conditions were studied and screened through a comparison among the reaction results. It showed that the highest yield of 1-phenylethanol was 88.6% when [MenQu]Cl was used as a catalyst; the ideal solvent was ethanol; the amount of catalyst was 20 mol%, and the reaction temperature was 25 °C. More substrates were employed to validate the universality of the developed method using such an IL. Moreover, potential reaction mechanisms and an IL recovery method were also suggested, which laid the foundation for its further applications in the field of sustainable chemistry and cleaner industrial production.