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Solvent-free mechanochemical mild oxidation method to enhance adsorption properties of chitosan

《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1416-4

摘要:

• Solvent-free chitosan oxidation is obtained by rapid mechanochemical reaction.

关键词: Chitosan     High energy ball milling     Mechanochemistry     Oxidation    

Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective catalytic oxidation of cyclohexane

《化学科学与工程前沿(英文)》 2022年 第16卷 第8期   页码 1211-1223 doi: 10.1007/s11705-022-2145-3

摘要: The one-step highly selective oxidation of cyclohexane into cyclohexanone and cyclohexanol as the essential intermediates of nylon-6 and nylon-66 is considerably challenging. Therefore, an efficient and low-cost catalyst must be urgently developed to improve the efficiency of this process. In this study, a Co3O4–CeO2 composite oxide catalyst was successfully prepared through ultrasound-assisted co-precipitation. This catalyst exhibited a higher selectivity to KA-oil, which was benefited from the synergistic effects between Co3+/Co2+ and Ce4+/Ce3+ redox pairs, than bulk CeO2 and/or Co3O4. Under the optimum reaction conditions, 89.6% selectivity to KA-oil with a cyclohexane conversion of 5.8% was achieved over Co3O4–CeO2. Its catalytic performance remained unchanged after five runs. Using the synergistic effects between the redox pairs of different transition metals, this study provides a feasible strategy to design high-performance catalysts for the selective oxidation of alkanes.

关键词: Co3O4–CeO2 composite oxides     cyclohexanone     cyclohexanol     ultrasonic-assisted co-precipitation     selective oxidation     solvent-free    

实现“不可行”的共聚反应以构筑氮掺杂多孔碳的理想聚合物前驱体 Article

亓士超, 陆筱杰, 楼寅聪, 周睿, 薛丁铭, 刘晓勤, 孙林兵

《工程(英文)》 2022年 第16卷 第9期   页码 154-161 doi: 10.1016/j.eng.2021.07.031

摘要:

某些预想的概念验证反应虽可能产生具有新功能或新应用潜力的材料,但最终常被证明是不可实现的或从商业角度上是不可行的。为了在溶剂环境中探索未知反应的反应条件,科研人员已付出了大量的努力,也浪费了大量的精力。因为人们普遍相信通过将反应物溶解在溶剂中,可以提高反应物的活性,从而促进反应。本研究发现了一个反常现象:在不同溶剂环境下,1,3,5-三(氯甲基)-2,4,6-三甲基苯与三聚氰胺的共聚反应都是无法实现的,然而利用无溶剂法却可成功地实现该反应。通过第一性原理计算和分子动力学模拟,证明了溶剂反应不具备的两个决定性因素,即由副产物的及时释放所推动的反应平衡和活化单体分子在固相中的受限热运动却可基于无溶剂法实现。由于具有较高的芳香性和氮杂环含量,由无溶剂法得到的共聚物表现出良好的应用潜力,可作为制备氮掺杂多孔碳的前驱体,使氮掺杂多孔碳具有令人满意的碳产率、理想的残氮含量、理想的结构特性,与最近报道的其他代表性同类吸附剂相比,在二氧化碳捕获能力方面展现出竞争潜力。

关键词: 无溶剂法     溶剂效应     共聚反应     氮掺杂多孔碳    

Expression and characterization of a CALB-type lipase from

Jiang-Wei Shen, Xue Cai, Bao-Juan Dou, Feng-Yu Qi, Xiao-Jian Zhang, Zhi-Qiang Liu, Yu-Guo Zheng

《化学科学与工程前沿(英文)》 2020年 第14卷 第5期   页码 868-879 doi: 10.1007/s11705-019-1889-x

摘要: A lipase from SRZ2 (SRL) with 73% amino acid sequence identity to lipase B (CALB) was cloned and overexpressed in . The recombinant SRL showed a preference for short-chain -nitrophenyl esters. It achieved maximum activity at pH 8.0 and 65°C for -nitrophenyl hexanoate (C6) with and / values of 0.14 mmol∙L and 1712 min ∙mmol∙L at 30°C, respectively. SRL displayed excellent thermostability and pH stability, retaining more than 79% of its initial activity after incubation at 60°C for 72 h and 75% at pH 3 to 11 for 72 h. It also maintained most of its activity in the presence of inhibitors and detergents except sodium dodecyl sulfate, and it tolerated organic solvents. SRL was covalently immobilized and successfully used for ethyl hexanoate synthesis in cyclohexane or in a solvent-free system with a high conversion yield (>95%). Furthermore, high conversion yield was also achieved for the synthesis of various short-chain flavor esters when high substrate concentrations of 2 mol∙L were applied. This study indicated that a CALB-type lipase from SRZ2 showed great potential in organic ester synthesis.

关键词: lipase     Sporisorium reilianum     biochemical characterization     short-chain flavor ester     solvent-free system    

Regulation of radicals by hydrogen-donor solvent in direct coal liquefaction

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1689-1699 doi: 10.1007/s11705-022-2186-7

摘要: Radicals are important intermediates in direct coal liquefaction. Certain radicals can cause the cleavage of chemical bonds. At high temperatures, radical fragments can be produced by the splitting of large organic molecules, which can break strong chemical bonds through the induction pyrolysis of radicals. The reaction between the formation and annihilation of coal radical fragments and the effect of hydrogen-donor solvents on the radical fragments are discussed in lignite hydrogenolysis. Using the hydroxyl and ether bonds as indicators, the effects of different radicals on the cleavage of chemical bond were investigated employing density functional theory calculations and lignite hydrogenolysis experiments. Results showed that the adjustment of the coal radical fragments could be made by the addition of hydrogen-donor solvents. Results showed that the transition from coal radical fragment to H radical leads to the variation of product distribution. The synergistic mechanism of hydrogen supply and hydrogenolysis of hydrogen-donor solvent was proposed.

关键词: direct coal liquefaction     hydrogen-donor solvent     induced pyrolysis     radical mechanism     density functional theory calculations    

Micronization of curcumin with biodegradable polymer by supercritical anti-solvent using micro swirl

Kimthet Chhouk, Wahyudiono, Hideki Kanda, Shin-Ichro Kawasaki, Motonobu Goto

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 184-193 doi: 10.1007/s11705-017-1678-3

摘要: Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological activities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-human immunodeficiency virus, and anti-microbial activity. In this work, a swirl mixer was employed to produce the micronized curcumin with polyvinylpyrrolidone (PVP) by the supercritical anti-solvent process to improve the bioavailability of curcumin. The effects of operating parameters such as curcumin/PVP ratio, feed concentration, temperature, pressure, and CO flow rate were investigated. The characterization and solubility of particles were determined by using scanning electron microscopy, Fourier Transform Infrared spectroscopy, and ultra-violet-visible spectroscopy. The result shows that the optimal condition for the production of curcumin/PVP particles is at curcumin/PVP ratio of 1:30, feed concentration of 5 mg·mL , temperature of 40 °C, pressure of 15 MPa, and CO flow rate of 15 mL·min . Moreover, the dissolution of curcumin/PVP particles is faster than that of raw curcumin.

关键词: micronization     curcumin     polyvinylpyrrolidone     supercritical anti-solvent     swirl mixer    

Study of an artificial boundary condition based on the damping-solvent extraction method

Qiang XU, Jianyun CHEN, Jing LI, Mingming WANG

《结构与土木工程前沿(英文)》 2012年 第6卷 第3期   页码 281-287 doi: 10.1007/s11709-012-0167-5

摘要: A new artificial boundary condition for time domain analysis of a structure-unlimited-foundation system was proposed. The boundary condition was based on the damping-solvent extraction method. The principle of the damping-solvent extraction method was described. An artificial boundary condition was then established by setting two spring-damper systems and one artificial damping limited region. A test example was developed to verify that the proposed boundary condition and model had high precision. Compared with the damping-solvent extraction method, this boundary condition is easier to be applied to finite element method (FEM)-based numerical calculations.

关键词: damping-solvent extraction method     structure-unlimited-foundation system     spring-damper system     artificial damping limited region     finite element method    

Deep eutectic solvent inclusions for high- composite dielectric elastomers

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 996-1002 doi: 10.1007/s11705-022-2138-2

摘要: Recent advances in novel electroactive devices have placed new requirements on material development. High-performance dielectric elastomers with good mechanical stretchability and high dielectric constant are under high demand. However, the current strategy for fabricating these materials suffers from high cost or low thermal stability, which greatly hinders large-scale industrial production. Herein, we have successfully developed a novel strategy for improving the dielectric constant of polymeric elastomers via deep eutectic solvent inclusion by taking advantage of the low cost, convenient and environmentally benign synthesis process and high ionic conductivity from deep eutectic solvents. The as-prepared composite elastomers showed good stretchability and a greatly enhanced dielectric constant with a negligible increase in dielectric dissipation. Moreover, we have proven the universality of our strategy by using different types of deep eutectic solvents. It is believed that low-cost, easy-synthesis and environmentally friendly deep eutectic solvents including composite elastomers are highly suitable for large-scale industrial production and can greatly broaden the application fields of dielectric elastomers.

关键词: composite materials     deep eutectic solvent     dielectric elastomer     high dielectric constant    

A new procedure combining GC-MS with accelerated solvent extraction for the analysis of phthalic acid

Tingting MA, Ying TENG, Peter CHRISTIE, Yongming LUO, Yongshan CHEN, Mao YE, Yujuan HUANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 31-42 doi: 10.1007/s11783-012-0463-2

摘要: An optimized procedure based on gas chromatography-mass spectrometry (GC-MS) combined with accelerated solvent extraction (ASE) is developed for the analysis of six phthalic acid esters (PAEs), which are priority soil pollutants nominated by United States Environmental Protection Agency (USEPA). Quantification of PAEs in soil employs ultrasonic extraction (UE) (USEPA 3550) and ASE (USEPA 3545), followed by clean up procedures involving three different chromatography columns and two combined elution methods. GC-MS conditions under selected ion monitoring (SIM) mode are described and quality assurance and quality control (QA/QC) criteria with high accuracy and sensitivity for target analytes were achieved. Method reliability is assured with the use of an isotopically labeled PAE, di- -butyl phthalate-d4 (DnBP-D4), as a surrogate, and benzyl benzoate (BB) as an internal standard, and with the analysis of certified reference materials (CRM). QA/QC for the developed procedure was tested in four PAE-spiked soils and one PAE-contaminated soil. The four spiked soils were originated from typical Chinese agricultural fields and the contaminated soil was obtained from an electronic waste dismantling area. Instrument detection limits (IDLs) for the six PAEs ranged 0.10–0.31 μg·L and method detection limits (MDLs) of the four spiked soils varied from a range of 20–70 μg·kg to a range of 90– 290 μg·kg . Linearity of response between 20 μg·L and 2 mg·L was also established and the correlation coefficients ( ) were all>0.998. Spiked soil matrix showed relative recovery rates between 75 and 120% for the six target compounds and about 93% for the surrogate substance. The developed procedure is anticipated to be highly applicable for field surveys of soil PAE pollution in China.

关键词: phthalic acid esters     quality assurance and quality control     soil type     accelerated solvent extraction     certified reference materials    

Purification of artemisinin from quercetin by anti-solvent crystallization

Chandrakant R. MALWADE, Haiyan QU, Ben-Guang RONG, Lars P. CHRISTENSEN

《化学科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 72-78 doi: 10.1007/s11705-013-1305-x

摘要: In the present work, anti-solvent crystallization of artemisinin from four different organic solvents (methanol, ethanol, acetonitrile, and acetone) was studied. Water was used as anti-solvent. The effect of an impurity (quercetin) on the performance of anti-solvent crystallization of artemisinin was investigated. The fundamental process data such as solubility of artemisinin in pure organic solvents and their binary mixtures with varying composition water were measured at room temperature. The solubility of quercetin was measured only in pure organic solvents at room temperature. Anti-solvent crystallization experiments were designed based on the fundamental process data determined. Firstly, the anti-solvent crystallization of artemisinin without impurity was performed from all four organic solvents and then the experiments were repeated with addition of an impurity (quercetin) while keeping all other process parameters constant. Two different concentrations of impurity, i.e., 10% and 50% of its solubility, in the respective organic solvents at room temperature were used. The effect of impurity on performance of anti-solvent crystallization was evaluated by comparing the yield and purity of the artemisinin obtained with those in the absence of impurity. Results of the present work demonstrated that the presence of quercetin in the solution does not affect the final yield of artemisinin from the solution of each of four organic solvents used. However, the purity of artemisinin crystals were reduced when quercetin concentration was 50% of its solubility in all solvents studied.

关键词: anti-solvent crystallization     artemisinin     quercetin     solubility     Artemisia annua    

Review of solvent based carbon-dioxide capture technologies

Kathryn A. MUMFORD,Yue WU,Kathryn H. SMITH,Geoffrey W. STEVENS

《化学科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 125-141 doi: 10.1007/s11705-015-1514-6

摘要: Currently, a large proportion of global fossil fuel emissions originate from large point sources such as power generation or industrial processes. This trend is expected to continue until the year 2030 and beyond. Carbon capture and storage (CCS), a straightforward and effective carbon reduction approach, will play a significant role in reducing emissions from these sources into the future if atmospheric carbon dioxide (CO ) emissions are to be stabilized and global warming limited below a threshold of 2 °C. This review provides an update on the status of large scale integrated CCS technologies using solvent absorption for CO capture and provides an insight into the development of new solvents, including advanced amine solvents, amino acid salts, carbonate systems, aqueous ammonia, immiscible liquids and ionic liquids. These proposed new solvents aim to reduce the overall cost CO capture by improving the CO absorption rate, CO capture capacity, thereby reducing equipment size and decreasing the energy required for solvent regeneration.

关键词: large scale     carbon dioxide     carbon capture     solvent absorption    

Vanadium(IV) solvent extraction enhancement in high acidity using di-(2-ethylhexyl)phosphoric acid with

《化学科学与工程前沿(英文)》 2023年 第17卷 第1期   页码 56-67 doi: 10.1007/s11705-022-2185-8

摘要: Separation of vanadium from black shale leaching solution at low pH is very meaningful, which can effectively avoid the generation of alkali neutralization slag and the resulting vanadium loss. In this study, coordination mechanism of vanadium in acid leaching solution at low pH was investigated with the intervention of chloride ions. Under the conditions of pH 0.8, di-(2-ethylhexyl)phosphoric acid concentration of 20%, phase ratio of 1:2, and extraction time of 8 min, the vanadium extraction could reach 80.00%. The Fourier transform infrared and electrospray ionization results reveal that, despite the fact that the chloride ion in the leachate could significantly promote vanadium extraction, the chloride ion does not enter the organic phase, indicating an intriguing phenomenon. Among Cl–V, SO42−–V, and H2O–V, the V–Cl bond is longer and the potential difference between coordinate ions and vanadium is smaller. Therefore, VO2+ gets easily desorbed with chloride ions and enter the organic phase. At the same time, the hydrogen ions of di-(2-ethylhexyl)phosphoric acid also enter the water phase more easily, which reduces the pH required for the extraction reaction.

关键词: vanadium     black shale     solvent extraction     high acidity extraction    

Solvent-resistant porous membranes using poly(ether−ether ketone): preparation and application

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1536-1559 doi: 10.1007/s11705-022-2221-8

摘要: Poly(ether−ether ketone) (PEEK) is a linear aromatic macromolecule, which can form semi-crystalline aggregative status, allowing PEEK materials to have strong environment tolerance and excellent physicochemical properties. PEEK materials have become a promising alternative to fabricate particular membranes used in extreme conditions. In the past few decades, many researches and evolutions have emerged in membrane fabrication with PEEK materials and its applications for treating organic solvents and their mixtures; however, there are little systematic and comprehensive literature to summarize fabrication approaches, compile applications, and elaborate PEEK property-structure relationship. In this review, the main approaches to fabricate PEEK-based membranes are illustrated concretely, including conventional thermal-induced and non-solvent-induced phase separation, and novel chemical-induced crystallization; the representative applications in ultrafiltration, nanofiltration and membrane contactor containing organic solvents are demonstrated systematically. Meanwhile, the mechanism to tune PEEK solubility in solvents, which can be achieved by altering monomers in synthesis processes or changing membrane preparation routes, is deeply analyzed. Moreover, the existing problems and the future prospects are also discussed. This review provides positive guidance for designing and fabricating membranes using PEEK and its derivative materials for task-specific applications in harsh conditions.

关键词: PEEK     phase inversion     solvent-resistant membrane     nanofiltration     membrane contactor    

Nucleation and growth mechanism of cefodizime sodium at different solvent compositions

Xinwei ZHANG, Shudong ZHANG, Xiaodan SUN, Zequn YIN, Quanjie LIU, Xiwen ZHANG, Qiuxiang YIN

《化学科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 490-495 doi: 10.1007/s11705-013-1350-5

摘要: The induction time of cefodizime sodium was measured in ethanol-water at different solvent compositions by the laser technology measurement. The results indicate that the solvent composition played an important role in the supersaturation and the nucleation process of cefodizime sodium solution. According to the modified classical nucleation theory, the nucleation and growth mechanism were identified. The correlation results show that heterogeneous nucleation dominated the nucleation process at lower supersaturation, where homogeneous nucleation is the most important mechanism at higher supersaturation. Based on the correlated results, the 2D mediated growth mechanism had the highest correlation coefficients ( ), so this mechanism was selected as the proper growth mechanism for cefodizime sodium.

关键词: cefodizime sodium     induction time     primary nucleation     growth mechanism    

Extraction of hydrogen chloride by a coupled reaction-solvent extraction process

Yunzhao Li,Xingfu Song,Guilan Chen,Shuying Sun,Yanxia Xu,Jianguo Yu

《化学科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 479-487 doi: 10.1007/s11705-015-1512-8

摘要: A coupled reaction-solvent extraction process was used to remove HCl from a simulated distiller waste. The extraction performances of various extractants and diluents were compared and the apparent basicity of N235 (a mixture of tertiary amines) in various diluents was determined. The best results were obtained using N235 and isoamyl alcohol as the extractant and diluent, respectively. The yield of HCl from the coupled extraction was 75% with this extraction system. The mechanisms for the removal of HCl in both the direct and coupled extractions were investigated. For the coupled extraction, the formation of an R NHCl ion-pair complex was involved in the HCl removal. For the direct extraction, the mechanism involved the formation of hydrogen bonds at high concentrations of HCl.

关键词: hydrogen chloride     distiller waste     coupled reaction and solvent extraction     N235     extraction mechanism    

标题 作者 时间 类型 操作

Solvent-free mechanochemical mild oxidation method to enhance adsorption properties of chitosan

期刊论文

Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective catalytic oxidation of cyclohexane

期刊论文

实现“不可行”的共聚反应以构筑氮掺杂多孔碳的理想聚合物前驱体

亓士超, 陆筱杰, 楼寅聪, 周睿, 薛丁铭, 刘晓勤, 孙林兵

期刊论文

Expression and characterization of a CALB-type lipase from

Jiang-Wei Shen, Xue Cai, Bao-Juan Dou, Feng-Yu Qi, Xiao-Jian Zhang, Zhi-Qiang Liu, Yu-Guo Zheng

期刊论文

Regulation of radicals by hydrogen-donor solvent in direct coal liquefaction

期刊论文

Micronization of curcumin with biodegradable polymer by supercritical anti-solvent using micro swirl

Kimthet Chhouk, Wahyudiono, Hideki Kanda, Shin-Ichro Kawasaki, Motonobu Goto

期刊论文

Study of an artificial boundary condition based on the damping-solvent extraction method

Qiang XU, Jianyun CHEN, Jing LI, Mingming WANG

期刊论文

Deep eutectic solvent inclusions for high- composite dielectric elastomers

期刊论文

A new procedure combining GC-MS with accelerated solvent extraction for the analysis of phthalic acid

Tingting MA, Ying TENG, Peter CHRISTIE, Yongming LUO, Yongshan CHEN, Mao YE, Yujuan HUANG

期刊论文

Purification of artemisinin from quercetin by anti-solvent crystallization

Chandrakant R. MALWADE, Haiyan QU, Ben-Guang RONG, Lars P. CHRISTENSEN

期刊论文

Review of solvent based carbon-dioxide capture technologies

Kathryn A. MUMFORD,Yue WU,Kathryn H. SMITH,Geoffrey W. STEVENS

期刊论文

Vanadium(IV) solvent extraction enhancement in high acidity using di-(2-ethylhexyl)phosphoric acid with

期刊论文

Solvent-resistant porous membranes using poly(ether−ether ketone): preparation and application

期刊论文

Nucleation and growth mechanism of cefodizime sodium at different solvent compositions

Xinwei ZHANG, Shudong ZHANG, Xiaodan SUN, Zequn YIN, Quanjie LIU, Xiwen ZHANG, Qiuxiang YIN

期刊论文

Extraction of hydrogen chloride by a coupled reaction-solvent extraction process

Yunzhao Li,Xingfu Song,Guilan Chen,Shuying Sun,Yanxia Xu,Jianguo Yu

期刊论文