A series of adamantane-based ionic liquids (ADM-ILs) with [MFn]− anions were synthesized as cocatalysts for the alkylation of isobutane and butene. By systematically tuning the structures of the cation and anion and their combination, we obtained the optimized ionic liquid, ADM-C12-SbF6, which exhibited significant enhancements in the C8 selectivities [especially to trimethylpentanes (TMPs)], the research octane number (RON) of the alkylate products, and the lifetime of sulfuric acid. The selectivity to TMPs was improved from 81.9% to 84.5%, and the alkylate RON was improved from 96.6 to 98.6 upon the addition of the ADM-ILs. In addition, the lifetimes of the ADM-IL/H2SO4 systems were increased to twice that of H2SO4 alone. Based on experimental measurements and DFT calculations, all of these enhancements were attributed to the multifunctions cooperatively integrated into the task-specific ADM-ILs, such as surfactant action, improving the interfacial properties of the acid/hydrocarbon biphases; buffer action, stabilizing the acidity changes during the reaction process; and hydride donor action, increasing the H– transfer rate, which promoted the production of TMPs. This study is beneficial for improving the isobutane alkylation process catalyzed by concentrated sulfuric acid.

Dissolution thermodynamics of camptothecine in chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed organic solvents were studied and correlated. The solubility of camptothecine in the above solvents was measured over the temperature range of 275.76–328.42 K at around 3 K intervals at atmospheric pressure. Experimental results showed that the solubility of camptothecine in the mixtures solvents increased with the increasing temperature. The mole fraction solubility of camptothecine reached a maximum at the mole fraction of chloroform 0.8016 in chloroform + methanol mixed solvent and 0.8031 in chloroform + ethanol mixed solvent. The experimental solubility data were well-correlated by using the modified Apelblat equation, the λh equation, and the ideal equation, respectively. The λh equation was proved to be the best-fit model for correlating the solubility of camptothecine from the analysis of the Akaike’s Information Criterion (AIC).

The synthesis of d-isoascorbyl stearate from d-isoascorbic acid and stearic acid with immobilized lipase (Novozym®435) as catalyst was studied. Response surface methodology and Box-Behnken design with six variables and three levels were employed to evaluate the effects of processing conditions on the conversion of d-isoascorbic acid. The results confirmed that the response surface method and statistical analysis were proved to be useful in developing optimal conditions for d-isoascorbyl stearate synthesis. The optimum conditions were predicted as follows: reaction temperature 48 °C, reaction time 17.7 h, immobilized lipase amount 50.0 % (w/w, of d-isoascorbic acid), substrate molar ratio 9:1 (stearic acid to d-isoascorbic acid), d-isoascorbic acid concentration 0.14 mol/L (based on solvent), 4A molecular sieve addition 200 g/L (based on solvent), and the optimal conversion was 90.6 %. Through the kinetics model fitting of the esterification, it was considered that the esterification conformed to a Ping–Pong bi–bi kinetic model with d-isoascorbic acid inhibition, and the obtained kinetic constants showed that the inhibition of d-isoascorbic acid and the enzyme affinity to substrate were abate with the increase of the reaction temperature.

γ-Valerolactone, which can be produced from lignocellulosic biomass, has drawn increasing attention recently because of its benign properties and versatile functions. However, the temperature employed for its production is relatively high. In order to save energy, herein, a new transformation process of α-angelica lactone to γ-valerolactone was carried out by using a series of room-temperature ionic liquids as solvents in a batch-type reactor. Among these ionic liquids, [Bmim]PF6 showed the best performance on the selective hydrogenation at 60 °C with a reaction time of 20 min. Interestingly, it was found that the reaction can also take place at a temperature as low as room temperature with complete conversion and nearly 100% selectivity, which greatly reduces the energy required for the production of γ-valerolactone. The reaction system of ionic liquid/catalyst showed good reusability. There was no obvious decrease in conversion and selectivity after 10 uses. Furthermore, the kinetics of the catalytic hydrogenation reaction of α-angelica lactone was studied to elucidate the reaction profile. Systematic kinetics experiments were carried out by varying the reaction temperature from 20 to 100 °C at 4.0 MPa, and the simulated data fits well with the first-order reaction law.Keywords: Hydrogenation; Ionic liquids; Kinetics; α-Angelica lactone; γ-Valerolactone

Two low viscous ionic liquids (ILs), 1-(2-hydroxyethyl)-3-methyl-imidazolium dicyanamide ([C2OHmim][DCA]) and 1-butyl-3-methylimidazolium ([Bmim][DCA]) were selected to mixed with aqueous 30 wt% monoethanolamine (MEA) for CO2 absorption. The solubility of CO2 in the aqueous mixtures of MEA + ILs was measured over a range of CO2 partial pressure of 10–800 kPa and ILs concentrations from 10 to 50 wt% at 313.15 K and 333.15 K. Correlations of solubility as a function of CO2 partial pressure have been conducted with deviation of ±1.5%. Moreover, the density and viscosity of pure ILs and MEA + ILs + H2O systems with different IL mass fractions were measured at temperature varying from 293.15 to 333.15 K.

The thermal stability and kinetics of isothermal decomposition of diosgenin were studied by thermogravimetry (TG) and Differential Scanning Calorimeter (DSC). The activation energy of the thermal decomposition process was determined from the analysis of TG curves by the methods of Flynn-Wall-Ozawa, Doyle, Šatava-Šesták and Kissinger, respectively. The mechanism of thermal decomposition was determined to be Avrami-Erofeev equation (n = 1/3, n is the reaction order) with integral form G(α) = [−ln(1 − α)]1/3 (α = 0.10–0.80). Ea and logA [s−1] were determined to be 44.10 kJ mol−1 and 3.12, respectively. Moreover, the thermodynamics properties of ΔH≠, ΔS≠, and ΔG≠ of this reaction were 38.18 kJ mol−1, −199.76 J mol−1 K−1, and 164.36 kJ mol−1 in the stage of thermal decomposition.

The solubility of diosgenin in methanol, ethanol (95%), isopropanol, acetone, acetic ether, and propyl acetate were measured at temperatures from (295.15 to 330.15) K using the synthetic method by a laser monitoring observation technique at atmospheric pressure. Its corresponding (solid + liquid) equilibrium data will provide essential support for industrial design and further theoretical studies. The solubility data of diosgenin in isopropanol, acetone, ethanol (95%), and acetic ether were correlated with Apelblat equation, and the experimental data of diosgenin in methanol and propyl acetate were also correlated with the λh model. The calculated values were good in agreement with the experimental values.Highlights► The solubility of diosgenin in different solvents has been obtained in this work. ► The results show that the three models agree well with the experimental data. ► The Apelblat equation was more accurate than the λh equation and the ideal model.

The solubility data of diosgenin in mixed systems of ethanol+1-propanol (1:1), ethanol+1-butanol (1:1), ethanol+isobutyl alcohol (1:1), methanol+isobutyl alcohol (1:1), methanol+isobutyl alcohol (1:4), ethanol+1-pentanol (1:1) and carbon tetrachloride were measured over the temperature range from 289.15 K to 334.15 K by a laser monitoring observation technique at atmospheric pressure, with all mixtures mixed by volume ratio. The Apelblat equation, the ideal solution model, and the λh equation are used to correlate the solubility data. The results show that the three models agree well with the experimental data, providing essential support for industrial design and further theoretical study.

In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. In this paper, we report a silicon, single-walled carbon nanotube, and ordered mesoporous carbon nanocomposite synthesized by an evaporation-induced self-assembly process, in which silicon nanoparticles and single-walled carbon nanotubes were added into the phenolic resol with F-127 for co-condensation. The ordered mesoporous carbon matrix and single-walled carbon nanotubes network could effectively accommodate the volume change of silicon nanoparticles, and the ordered mesoporous structure could also provide efficient channels for the fast transport of Li-ions. As a consequence, this hybrid material exhibits a reversible capacity of 861 mAh g−1 after 150 cycles at a current density of 400 mA g−1. It achieves significant improvement in the electrochemical performance when compared with the raw materials and Si nanoparticle anodes.