资源类型

期刊论文 1102

会议视频 25

会议信息 4

年份

2024 2

2023 170

2022 175

2021 191

2020 95

2019 40

2018 26

2017 50

2016 32

2015 35

2014 47

2013 41

2012 24

2011 23

2010 45

2009 30

2008 21

2007 35

2006 3

2005 2

展开 ︾

关键词

SARS-CoV-2 7

微波散射计 5

碳中和 5

COVID-19 4

Cu(In 4

HY-2 4

2019 3

2型糖尿病 3

GPS 3

Ga)Se2 3

HY-2 卫星 3

HY-2A卫星 3

代谢与免疫 3

光催化 3

工程管理 3

微波辐射计 3

营养健康 3

CCS 2

CO2利用 2

展开 ︾

检索范围：

排序： 展示方式：

Synthesis of magnetic Pb/Fe

Hualiang AN, Xinqiang ZHAO, Zhiguang JIA, Changcheng WU, Yanji WANG

《化学科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 215-218 doi: 10.1007/s11705-009-0055-2

摘要： To facilitate the recovery of Pb/SiO catalyst, magnetic Pb/Fe O /SiO samples were prepared separately by emulsification, sol-gel and incipient impregnation methods. The catalyst samples were characterized by means of X-ray diffraction and N adsorption-desorption, and their catalytic activity was investigated in the reaction for synthesizing propylene carbonate from urea and 1,2-propylene glycol. When the gelatin was applied in the preparation of Fe O at 60°C and the pH value was controlled at 4 in the preparation of Fe O /SiO , the Pb/Fe O /SiO sample shows good catalytic activity and magnetism. Under the reaction conditions of a reaction temperature of 180°C, reaction time of 2 h, catalyst percentage of 1.7 wt-% and a molar ratio of urea to PG of 1∶4, the yield of propylene carbonate attained was 87.7%.

关键词： Pb/Fe3O4/SiO2 magnetic particle     urea     1     2-propylene glycol     propylene carbonate    

HTML PDF 收藏

Polyethylene glycol-supported ionic liquid as a highly efficient catalyst for the synthesis of propylene

Rui YAO, Hua WANG, Jinyu HAN

《化学科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 239-245 doi: 10.1007/s11705-012-1297-y

摘要： The coupling reaction of propylene and CO to form propylene carbonate (PC) was promoted by an ionic liquid (IL) covalently bound to polyethylene glycol (PEG). The supported ionic liquid, which has both acidic and basic components, proved to be an active catalyst for PC synthesis under mild conditions. The effects of different cations and anions, reaction temperature, CO pressure, and reaction time were investigated. It was demonstrated that the acid group in the catalyst plays an important role in the reaction. With this system, a high PC yield (95%) was achieved under mild conditions (3.0 MPa, 120°C and 4 h) without a co-solvent. In addition, the catalyst was readily recovered and reused. Based on the experimental results, a plausible mechanism for the catalyst was proposed.

关键词： ionic liquid     PEG-supported ionic liquid     carbon dioxide     propylene carbonate    

HTML PDF 收藏

Optimization and simultaneous heat integration design of a coal-based ethylene glycol refining process

《化学科学与工程前沿（英文）》 2023年 第17卷 第9期   页码 1280-1288 doi: 10.1007/s11705-023-2301-4

摘要： Coal to ethylene glycol still lacks algorithm optimization achievements for distillation sequencing due to high-dimension and strong nonconvexity characteristics, although there are numerous reports on horizontal comparisons and process revamping. This scenario triggers the navigation in this paper into the simultaneous optimization of parameters and heat integration of the coal to ethylene glycol distillation scheme and double-effect superstructure by the self-adapting dynamic differential evolution algorithm. To mitigate the influence of the strong nonconvexity, a redistribution strategy is adopted that forcibly expands the population search domain by exerting external influence and then shrinks it again to judge the global optimal solution. After two redistributive operations under the parallel framework, the total annual cost and CO2 emissions are 0.61%/1.85% better for the optimized process and 3.74%/14.84% better for the superstructure than the sequential optimization. However, the thermodynamic efficiency of sequential optimization is 11.63% and 10.34% higher than that of simultaneous optimization. This study discloses the unexpected great energy-saving potential for the coal to ethylene glycol process that has long been unknown, as well as the strong ability of the self-adapting dynamic differential evolution algorithm to optimize processes described by the high-dimensional mathematical model.

关键词： ethylene glycol     redistribution     heat integration     optimization     parallel framework    

HTML PDF 收藏

Alkylation of benzene with propylene catalyzed by FeCl3-chloropyridine ionic liquid

SUN Xuewen, ZHAO Suoqi, LI Hui

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 292-295 doi: 10.1007/s11705-007-0053-1

摘要： Alkylation of benzene with propylene was carried out with FeCl3-chloro-butyl-pyridine (FeCl-[bpc]) ionic liquid as catalyst to obtain cumene. Significant improvements in propylene conversion and cumene selectivity under mild reaction conditions were attained by modification of the catalyst with HCl. Under 20ºC, 0.1 MPa, reaction time 5 min, mole ratio of benzene to propylene 10:1 and mass ratio of FeCl-[bpc] to benzene 1:100, conversion of propylene can increase from 83.60% to 100.00% and selectivity of cumene can increase from 90.86% to 98.47%. If reaction is carried out in following two stages, the result will be very good. At the initial stage of the reaction, alkylation is the main reaction and a higher conversion of propylene is obtained at a lower temperature. At the later stage of the reaction, transalkylation is the main reaction and selectivity to cumene can be increased by appropriately raising the reaction temperature.
HTML PDF 收藏

Chitosan/polyethylene glycol impregnated activated carbons: Synthesis, characterization and adsorption

Ehsan Salehi, Fereshteh Soroush, Maryam Momeni, Aboulfazl Barati, Ali Khakpour

《化学科学与工程前沿（英文）》 2017年 第11卷 第4期   页码 575-585 doi: 10.1007/s11705-017-1650-2

摘要： Novel modified activated carbons (ACs) with enhanced adsorptive properties were obtained coating by chitosan (CS), polyethylene glycol (PEG) and blends of the two polymers (0:1, 1:0, 1:1, 1:2 and 2:1 wt/wt) on ACs by an impregnation technique. The adsorption performances of the pristine, acidified and polymer-impregnated ACs were studied using methylene blue as a model adsorbate. The adsorbents were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and abrasion hardness tests. The average coating thicknesses were between 10 to 23 microns. The pore sizes, pore densities and pore capacities of the activated carbons increased as the wt-% PEG in the coating increased. The highest adsorption capacity (424.7 mg/g) was obtained for the chitosan-coated ACs and this adsorption was well described by the Langmuir isotherm model. The kinetic results were best described by the pseudo-second-order kinetic model. The highest rate constant was obtained with the ACs modified with the CS:PEG (2:1) coating and this result was almost 2.6 times greater than that of the unmodified ACs. The CS/PEG impregnated ACs also displayed superior hardness (~90%), compared to unmodified ACs (~85%). Overall the chitosan had a greater effect on improving adsorption capacity whereas the polyethylene glycol enhanced the adsorption rate.

关键词： carbon biocomposites     impregnation     chitosan     polyethylene glycol     image processing    

HTML PDF 收藏

Effects of a dynamic membrane formed with polyethylene glycol on the ultrafiltration of natural organic

Boksoon KWON, Noeon PARK, Jaeweon CHO,

《环境科学与工程前沿（英文）》 2010年 第4卷 第2期   页码 172-182 doi: 10.1007/s11783-010-0002-y

摘要： The formation of a dynamic membrane (DM) was investigated using polyethylene glycol (PEG) (molecular weight of 35000 g/mol, concentration of 1 g/L). Two natural organic matters (NOM), Dongbok Lake NOM (DLNOM) and Suwannee River NOM (SRNOM) were used in the ultrafiltration experiments along with PEG. To evaluate the effects of the DM with PEG on ultrafiltration, various transport experiments were conducted, and the analyses of the NOM in the membrane feed and permeate were performed using high performance size exclusion chromatography, and the pore size distribution ( PSD) and molecular weight cut off ( MWCO) were determined. The advantages of DM formed with PEG can be summarized as follows: (1) PEG interferes with NOM transmission through the ultrafiltration membrane pores by increasing the retention coefficient of NOM in UF membranes, and (2) low removal of NOM by the DM is affected by external factors, such as pressure increases during UF membrane filtration, which decreases the PSD and MWCO of UF membranes. However, a disadvantage of the DM with PEG was severe flux decline; thus, one must be mindful of both the positive and negative influences of the DM when optimizing the UF performance of the membrane.

关键词： dynamic membrane     natural organic matters     ultrafiltration membrane performance     effective PSD     effective molecular weight cutoff    

HTML PDF 收藏

Effect of triethylamine treatment of titanium silicalite-1 on propylene epoxidation

Juan XU,Yaquan WANG,Wenping FENG,Yi LIN,Shuhai WANG

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 478-487 doi: 10.1007/s11705-014-1453-7

摘要： Titanium silicalite-1(TS-1) treated with triethylamine (TEA) solution under different conditions was characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectrum (FTIR), ultraviolet-visible diffuse reflectance spectrum (UV-Vis), nitrogen physical adsorption and desorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The characterization results show that many irregular hollows are generated in the TS-1 crystals due to the random dissolution of framework silicon and the volume of the hollow cavities increase with increasing the TEA concentration, and the treatment temperature and time. The modified TS-1 samples improved in varying degrees the catalyst life for the epoxidation of propylene in a fixed-bed reactor probably due to the generation of the hollows to make it easy for the reactants and products to diffuse out of the channels.

关键词： titanium silicalite-1     triethylamine     hollow cavity     epoxidation of propylene     catalyst life    

HTML PDF 收藏

Encapsulation of polyethylene glycol in cellulose-based porous capsules for latent heat storage and light-to-thermal

《化学科学与工程前沿（英文）》 2023年 第17卷 第8期   页码 1038-1050 doi: 10.1007/s11705-022-2279-3

摘要： Phase change materials are potential candidates for the application of latent heat storage. Herein, we fabricated porous capsules as shape-stable materials from cellulose-based polyelectrolyte complex, which were first prepared using cellulose 6-(N-pyridinium)hexanoyl ester as the cationic polyelectrolyte and carboxymethyl cellulose as the anionic polyelectrolyte to encapsulate polyethylene glycol by the vacuum impregnation method. Furthermore, the multi-walled carbon nanotube or graphene oxide, which were separately composited into the polyelectrolytes complex capsules to enhance thermal conductivity and light-to-thermal conversion efficiency. These capsules owned a typical core–shell structure, with an extremely high polyethylene glycol loading up to 34.33 g∙g‒1. After loading of polyethylene glycol, the resulted cellulose-based composite phase change materials exhibited high thermal energy storage ability with the latent heat up to 142.2 J∙g‒1, which was 98.5% of pure polyethylene glycol. Further results showed that the composite phase change materials demonstrated good form-stable property and thermal stability. Moreover, studies involving light-to-thermal conversion determined that composite phase change materials exhibited outstanding light-to-thermal conversion performance. Considering their exceptional comprehensive features, innovative composite phase change materials generated from cellulose presented a highly interesting choice for thermal management and renewable thermal energy storage.

关键词： cellulose     polyelectrolytes     phase change materials     thermal energy storage     light-to-thermal conversion    

HTML PDF 收藏

Methanol to propylene: the effect of iridium and iron incorporation on the HZSM-5 catalyst

Alireza MOHAMMADREZAEI, Sadegh PAPARI, Mousa ASADI, Abas NADERIFAR, Reza GOLHOSSEINI

《化学科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 253-258 doi: 10.1007/s11705-012-0902-4

摘要： The effect of iridium and iron impregnation of HZSM-5 zeolite on the methanol to propylene reaction (MTP) was investigated. The selectivities of propylene and other hydrocarbons, and the conversion of methanol were compared by performing MTP in a small pilot plant. The results indicate that HZSM-5 zeolite modified by iron and iridium increased propylene selectivity by 6.3% and 8%, respectively. The selectivity of propylene was higher for Ir/H-ZSM-5 than for Fe/H-ZSM-5, where Fe/H-ZSM-5 was more stable than Ir/H-ZSM-5. Analytic techniques, including X-ray diffraction, BET surface area, temperature-programmed desorption of ammonia, and inductively coupled plasma atomic emission spectroscopy, were used to characterize the modified zeolites as well as the parent zeolites.

关键词： HZSM-5     promoter     iridium     iron     MTP    

HTML PDF 收藏

Modification of polycarbonateurethane surface with poly(ethylene glycol) monoacrylate and phosphorylcholine

Jing YANG,Juan LV,Bin GAO,Li ZHANG,Dazhi YANG,Changcan SHI,Jintang GUO,Wenzhong LI,Yakai FENG

《化学科学与工程前沿（英文）》 2014年 第8卷 第2期   页码 188-196 doi: 10.1007/s11705-014-1414-1

摘要： Poly(ethylene glycol) monoacrylate (PEGMA) is grafted onto polycarbonateurethane (PCU) surface via ultraviolet initiated photopolymerization. The hydroxyl groups of poly(PEGMA) on the surface react with one NCO group of isophorone diisocyanate (IPDI) and another NCO group of IPDI is then hydrolyzed to form amino terminal group, which is further grafted with phosphorylcholine glyceraldehyde to establish a biocompatible hydrophilic structure on the surface. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the successful grafting of both PEG and phosphorylcholine functional groups on the surface. The decrease of the water contact angle for the modified film is caused by synergic effect of PEG and phosphorylcholine, which both have the high hydrophilicity. Furthermore, the number of platelets adhered is relative low on the synergetically modified PCU film compared with the PCU film modified only by poly(PEGMA). Our synergic modification method using both PEG and phosphorylcholine may be applied in surface modification of blood-contacting biomaterials and some relevant devices.

关键词： poly(ethylene glycol) monoacrylate     phosphorylcholine     polycarbonateurethane     surface modification     anti-platelet adhesion     biomaterials    

HTML PDF 收藏

Effect of polyethylene glycol on the crystallization, rheology and foamability of poly(lactic acid) containing

《化学科学与工程前沿（英文）》 2023年 第17卷 第12期   页码 2074-2087 doi: 10.1007/s11705-023-2342-8

摘要： In this study, the rheological properties, crystallization and foaming behavior of poly(lactic acid) with polyamide 6 nanofibrils were examined with polyethylene glycol as a compatibilizer. Polyamide 6 particles were deformed into nanofibrils during drawing. For the 10% polyamide 6 case, polyethylene glycol addition reduced the polyamide 6 fibril diameter from 365.53 to 254.63 nm, owing to the smaller polyamide 6 particle size and enhanced interface adhesion. Rheological experiments revealed that the viscosity and storage modulus of the composites were increased, which was associated with the three-dimensional entangled network of polyamide 6 nanofibrils. The presence of higher aspect ratio polyamide 6 nanofibrils substantially enhanced the melt strength of the composites. The isothermal crystallization kinetics results suggested that the polyamide 6 nanofibrils and polyethylene glycol had a synergistic effect on accelerating poly(lactic acid) crystallization. With the polyethylene glycol, the crystallization half-time reduced from 103.6 to 62.2 s. Batch foaming results indicated that owing to higher cell nucleation efficiency, the existence of polyamide 6 nanofibrils led to a higher cell density and lower expansion ratio. Furthermore, the poly(lactic acid)/polyamide 6 foams exhibited a higher cell density and expansion ratio than that of the foams without polyethylene glycol.

关键词： poly(lactic acid)     foaming     microfibrillation     rheological property     crystallization    

HTML PDF 收藏

Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

《化学科学与工程前沿（英文）》 2022年 第16卷 第5期   页码 720-730 doi: 10.1007/s11705-021-2098-y

摘要： A non-toxic and environmentally safe diluent, acetyl tributyl citrate, was employed to prepare poly(vinylidene fluoride)-co-hexafluoropropylene membranes via thermally induced phase separation. Effects of the polymer concentration on the phase diagram, membrane morphology, hydrophobicity, pore size, porosity and mechanical properties (tensile stress and elongation at break) were investigated. The results showed that the pore size and porosity tended to decrease with increasing polymer concentration, whereas the contact angle, liquid entry pressure and mechanical properties showed the opposite trend. In direct contact membrane distillation operation with 3.5 wt-% sodium chloride solution as the feed solution, the prepared membranes performed high salt rejection (>99.9%). Furthermore, the prepared membranes retained excellent performance in long-term stability tests regarding the permeate flux and salt rejection.

关键词： poly(vinylidene fluoride)-co-hexafluoropropylene     thermally induced phase separation     non-toxic diluent     direct contact membrane distillation    

HTML PDF 收藏

Determination of the diffusion of poly(ethylene glycol) in polypropylene using ATR-FTIR

Hanjia CHEN, Xuhua SHI, Yafei ZHU, Yi ZHANG, Jiarui XU,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 336-341 doi: 10.1007/s11705-009-0230-5

摘要： The diffusion of poly(ethy1ene glycol) (PEG) in polypropylene (PP) was investigated using attenuated total reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Atomic Force Micrograph (AFM), and Scanning Electron Microscopy (SEM). It has been found that the diffusion of PEG in PP was greatly affected by the annealing temperature and the molecular weight of PEG. Higher temperature was in favor of PEG to diffuse in PP with fast velocity and reached diffusion equilibrium with shorter time. PEG with higher molecular weight was distributed in PP with bigger phase domains and had lower diffusivity, which resulted in its lesser enrichment on the surface of the PP blend film.

关键词： diffusion     polypropylene     molecular     diffusion equilibrium     attenuated    

HTML PDF 收藏

Impact of dimethyl ether on engine seal materials

WU Ning, ZHANG Wugao, HUANG Zhen

《能源前沿（英文）》 2008年 第2卷 第3期   页码 279-284 doi: 10.1007/s11708-008-0042-1

摘要： The resistance of many kinds of rubber materials to dimethyl ether (DME) was studied. Both the mass and volume change of rubber materials, which were put in DME and then exposed to the air for different periods of time were measured. The results show that fluorine rubber (FKM), silicone rubber (SIR), and nitrile rubber (NBR) are unsuitable as seal materials for DME engines. Common polyvinylchloride (PVC) dissolved completely in DME, which has almost no impact on vulcanizing nylon material. The constitution of ethylene propylene terpolymer rubber (EPDM) has a major impact on its resistance to DME. A kind of EPDM with good resistance to DME was found, whose reliability was validated by 100 hours of DME engine operation.

关键词： impact     Common polyvinylchloride     different     constitution     ethylene propylene    

HTML PDF 收藏

Deactivation and regeneration of TS-1/SiO

Hainan SHI, Yaquan WANG, Guoqiang WU, Wenping FENG, Yi Lin, Teng ZHANG, Xing JIN, Shuhai WANG, Xiaoxue WU, Pengxu YAO

《化学科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 202-209 doi: 10.1007/s11705-013-1328-3

摘要： TS-1/SiO catalyst for the epoxidation of propylene with hydrogen peroxide in a fixed-bed reactor has been investigated. The catalyst activity decreases gradually with the online reaction time, but the selectivity of propylene epoxide is kept at about 93%. The fresh, deactivated and regenerated catalysts were characterized with X-ray diffraction, Fourier transform infrared spectroscopy, ultra-violet-visible diffuse reflectance, Brunner-Emmett-Teller method and thermogravimetric analysis, and the deactivated catalyst was regenerated with H O /methanol solution. Compared with the fresh catalyst, both the framework structure and the content of titanium in the framework of the deactivated and regenerated TS-1/SiO catalysts were not changed. The major reason of the catalyst deactivation was the blockage of the channels of the catalyst by bulky organic by-products, which covered the active centers of titanium in TS-1. The deposited materials on the deactivated TS-1/SiO catalyst could be removed by treatment with hydrogen peroxide/methanol solution or pure methanol; the higher the treatment temperature and the higher the concentration of H O in methanol, the higher the extent of the regeneration. The regeneration treatment did not influence the product selectivity in the propylene epoxidation.

关键词： TS-1/SiO2     epoxidation of propylene     fixed-bed reactor     deactivation     regeneration    

HTML PDF 收藏

标题 作者 时间 类型 操作

Synthesis of magnetic Pb/Fe

Hualiang AN, Xinqiang ZHAO, Zhiguang JIA, Changcheng WU, Yanji WANG

期刊论文

Polyethylene glycol-supported ionic liquid as a highly efficient catalyst for the synthesis of propylene

Rui YAO, Hua WANG, Jinyu HAN

期刊论文

Optimization and simultaneous heat integration design of a coal-based ethylene glycol refining process

期刊论文

Alkylation of benzene with propylene catalyzed by FeCl3-chloropyridine ionic liquid

SUN Xuewen, ZHAO Suoqi, LI Hui

期刊论文

Chitosan/polyethylene glycol impregnated activated carbons: Synthesis, characterization and adsorption

Ehsan Salehi, Fereshteh Soroush, Maryam Momeni, Aboulfazl Barati, Ali Khakpour

期刊论文

Effects of a dynamic membrane formed with polyethylene glycol on the ultrafiltration of natural organic

Boksoon KWON, Noeon PARK, Jaeweon CHO,

期刊论文

Effect of triethylamine treatment of titanium silicalite-1 on propylene epoxidation

Juan XU,Yaquan WANG,Wenping FENG,Yi LIN,Shuhai WANG

期刊论文

Encapsulation of polyethylene glycol in cellulose-based porous capsules for latent heat storage and light-to-thermal

期刊论文

Methanol to propylene: the effect of iridium and iron incorporation on the HZSM-5 catalyst

Alireza MOHAMMADREZAEI, Sadegh PAPARI, Mousa ASADI, Abas NADERIFAR, Reza GOLHOSSEINI

期刊论文

Modification of polycarbonateurethane surface with poly(ethylene glycol) monoacrylate and phosphorylcholine

Jing YANG,Juan LV,Bin GAO,Li ZHANG,Dazhi YANG,Changcan SHI,Jintang GUO,Wenzhong LI,Yakai FENG

期刊论文

Effect of polyethylene glycol on the crystallization, rheology and foamability of poly(lactic acid) containing

期刊论文

Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

期刊论文

Determination of the diffusion of poly(ethylene glycol) in polypropylene using ATR-FTIR

Hanjia CHEN, Xuhua SHI, Yafei ZHU, Yi ZHANG, Jiarui XU,

期刊论文

Impact of dimethyl ether on engine seal materials

WU Ning, ZHANG Wugao, HUANG Zhen

期刊论文

Deactivation and regeneration of TS-1/SiO

Hainan SHI, Yaquan WANG, Guoqiang WU, Wenping FENG, Yi Lin, Teng ZHANG, Xing JIN, Shuhai WANG, Xiaoxue WU, Pengxu YAO

期刊论文