Deep desulfurization of FCC gasoline by extraction with dicarboxylic acid-based deep eutectic solvents

A highly efficient extractive desulfurization system with dicarboxylic acid-based deep eutectic solvents (DESs) as extractants has been developed. A series of dicarboxylic acid-based DESs were synthesized by mixing n-butylpyridinium bromide ([BPY]Br) with different dicarboxylic acids. The extraction desulfurization performance of these DESs was investigated and optimized.     

应用化学模式识别对常用溶剂的分类研究

根据溶剂的５个选择性参数，ｘｅ，ｘｄ，ｘｎ，ｘｔ，ｘｍ，对常用的８１种溶剂应用化学模式识别方法进行了系统分析。各种模式识别方法（包括谱系聚类方法、非谱系聚类方法、主成分分析法和线性判别分析）的分类结果基本一致，且符合Ｓｎｙｄｅｒ应用其中３个参数以三角图形式进行溶剂分类的方法。本文结论有助于色谱分析、萃取和其它分离技术的溶剂选择。     

Thermogravimetric determination of the heat of vaporization of some highly polar solvents

Thermogravimetry was employed successfully in determining the enthalpies of vaporization of some industrially important solvents. The data obtained from the thermograms pertaining to weight loss were used for evaluating the rate of evaporation of the samples and were substituted in a form of the Clausius—Clapeyron equation for such determinations. Values of the enthalpies reported, using the thermogravimetric technique, were repeatable to within 1% and with an accuracy better than ±5% of the true values at the temperatures reported. Comparison with data obtained from other sources appears to be quite satisfactory.     

A circular dichroism study of the effect of some organic solvents on the actomyosin of sardine (Sardinops melanosticta)

Circular dichroism (CD) was used to study changes in conformation of sardine ( Sardinops melanosticta ) actomyosin after treatment with some organic solvents. Untreated sardine actomyosin showed two negative bands at 208 and 222 nm, typical of proteins possessing α-helix configurations. The water-miscible alcohols methanol, ethanol, isopropanol and n-butanol, and the water-immiscible solvents n-hexane, n-octanol, and dichloromethane altered the native conformation of sardine actomyosin. The degree of alteration of native sardine actomyosin was principally dependent on the alcohol concentration and temperature used for dewatering. The least damage occurred with isopropanol, or with 10 or 90% aqueous ethanol; most damage occurred with 40–50% aqueous ethanol. Dichloromethane and n-butanol increased the α-helical content of the native protein. Treatment with hydrophilic and hydrophobic solvents at 70 and 20°C unfolded the protein to form a random coil, but defatting treatment at 2°C caused little damage.     

Polymerization of t-butylacetylene initiated by tungsten carbene complex

Polymerization of t-butylacetylene initiated by a tungsten carbene complex (I) was investigated under various conditions. t-Butylacetylene was polymerized in high yield in chlorinated hydrocarbons such as CHCI₃ and CCI₄ and in the presence of AICI₃. The molar mass of the polymers formed was as high as 8.2 ×10⁴ ～ 3.2 × 10⁵. Moreover, when the solution of tungsten carbene complex in CCI₄ was irradiated with UV light, the molar mass was remarkably enhanced. This phenomenon may occur because tungsten dichlorocarbene immediately forms. Apparent rate constants were determined by gas chromatography. NMR spectra show a predominant characteristic of high cis content in the structure of poly(t-butylacetylene) in contrast to poly(phenylacetylene). The cis content increased ca. 11% when poly(t-butylacetylene) was heated in decalin at 110°C. X-Ray diffraction diagrams show that poly(t-butylacetylene) has an amorphous structure.     

Influence of the contact model and support characteristics on the partition constant for kinetically controlled synthesis of peptides

The influence of the physical characteristics of the support and the contact model on the partition constant (p) in kinetically controlled peptide synthesis was studied. Large values for p were obtained using a small pore size carrier and a recirculation reactor. However, with a larger pore size carrier and the same contact model, p values were lower, the latter conditions were more favorable for product synthesis.     

纳米纤维素限域钯纳米颗粒的室温催化活性及化学选择性

本文利用水合低共熔溶剂结合超声法制备了羧基化纤维素纳米纤丝(CNF),并利用其表面的羧基官能团为反应活性位点原位合成了具有均匀分散性和高负载量(9.6 wt%)的CNF-Pd复合催化剂.研究结果表明:CNF-Pd具有显著的限域特性,包括在CNF表面羧基官能团上原位固定生长Pd纳米颗粒的化学限域和CNF冷冻干燥过程中自组...     

Formation of oil‐in‐water (O/W) pickering emulsions via complexation between β‐cyclodextrin and selected organic solvents

Cyclodextrins (CDs) are cyclic oligosaccharides derived from the enzymatic degradation of starch. Emulsifying functionality of β‐cyclodextrin (β‐CD) upon its complexation with selected solvents (octanol, decane, and toluene) was studied. In several tests, the three‐phase systems containing the emulsion fraction in the middle position were obtained. The examination of variations in the phase behavior of the test systems showed that the decane/β‐CD/water system had the highest emulsion phase volume when β‐CD at concentration of 10% w/v was used. A reduction in interfacial tension (IFT) of the oil–water interface in each test system was observed with the following order: toluene, decane, and octanol. The precipitated fraction obtained upon centrifugation of the emulsion phase, was structurally characterized as the inclusion complex (IC) formed between β‐CD and each of the three test solvents. The wettability of the IC particles was determined through contact angle measurement and formation of the oil‐in‐water (O/W) Pickering emulsions was confirmed (θ_ow<90°). With use of size distribution data, the ICs particles as the microparticles (1–10 µm) were found to be the main species involved in the formation and stabilization of the emulsions.     

Promoted absorption of CO at high temperature by cuprous-based ternary deep eutectic solvents

Achieving efficient dissolution of carbon monoxide (CO) in the solvent is very helpful for the implementation of carbonylation reaction at ambient pressure. However, almost all of common solvents show very low solubilities of CO at high temperature. Herein, a series of cuprous-based ternary deep eutectic solvent (DES) was prepared by mixing imidazolium hydrochloride with CuCl and ZnCl₂. The ternary DES [BimH]Cl-CuCl-1.0ZnCl₂ exhibited very large CO absorption capacity (0.075 mol mol⁻¹, 1 bar) even at a high temperature (353.2 K), which is superior to all of the reported absorbents. Moreover, the ternary DES [BimH]Cl-CuCl-1.0ZnCl₂ could further promote the reactive absorption of CO to conduct the aminocarbonylation reaction effortlessly at ambient pressure, and thus the targeted products benzamides were obtained in 70–97 yields. We believe that this finding opens a new way to design advanced solvents for efficient capture of CO at high temperature.     

Photocatalytic oxidative of Keggin-type polyoxometalate ionic liquid for enhanced extractive desulfurization in binary deep eutectic solvents

A series of novel binary deep eutectic solvents (DESs) composed of choline chloride (ChCl) and formic acid (HCOOH) with different molar ratios have been successfully synthesized and applied in extractive desulfurization (EDS). Keggin-type polyoxometallate ionic liquid [TTPh]₃PW₁₂O₄₀ was prepared and used as catalyst to enhance the EDS capacity by means of photocatalytic oxidative process. Both of the DESs and [TTPh]₃PW₁₂O₄₀ ionic liquid catalyst were characterized in detail by Fourier transform infrared spectroscopy spectra (FT-IR), elemental analysis, and X-ray photoelectron spectroscopy (XPS). It was found that the molar ratios of ChCl:HCOOH had a major impact on desulfurization performance, and the optimal desulfurization capacity 96.5% was obtained by ChCl/5HCOOH. Besides dibenzothiophene (DBT), the desulfurization efficiencies of 4-methylbenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT), two kinds of DBT derivatives, were also investigated under the same experimental conditions. Moreover, the free radical scavenging experiments manifested that superoxide radical (·O₂^-) and hole (h⁺) played important roles in the desulfurization system. After further analysis of the oxidation products by gas chromatography-mass spectrometry (GC–MS), the possible reaction mechanism was proposed. Thus, photocatalytic oxidative has been proved to be one of the efficient approaches for enhancing the extractive desulfurization performance in DES.