科创中国

In this study a thin film composite (TFC) membrane with a Pebax/Task-specific ionic liquid (TSIL) blend selective layer was prepared. Defect-free Pebax/TSIL layers were coated successfully on a polysulfone ultrafiltration porous support with a polydimethylsiloxane (PDMS) gutter layer. Different parameters in the membrane preparation (e.g. concentration, coating time) were investigated and optimized. The morphology of the membranes was studied by scanning electron microscopy (SEM), while the thermal properties and chemical structures of the membrane materials were investigated by thermo-gravimetric analyzer (TGA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The CO₂ separation performance of the membrane was evaluated using a mixed gas permeation test. Experimental results show that the incorporation of TSIL into the Pebax matrix can significantly increase both CO₂ permeance and CO₂/N₂ selectivity. With the presence of water vapor, the membrane exhibits the best CO₂/N₂ selectivity at a relative humidity of around 75%, where a CO₂ permeance of around 500 GPU and a CO₂/N2 selectivity of 46 were documented. A further increase in the relative humidity resulted in higher CO₂ permeance but decreased CO₂/N₂ selectivity. Experiments also show that CO₂ permeance decreases with a CO₂ partial pressure increase, which is considered a characteristic in facilitated transport membranes.

Zhong De Dai;Lu Bai;Karoline Nåvik Hval;Xiang Ping Zhang;锁江 张;Li Yuan Deng

Science China Chemistry

2016

Pu Yang;Ling Wang;Yanyan Diao;Lei Wang;锁江 张

2015

Utilization of CO₂ (carbon dioxide) to synthesize useful organic compounds has attracted much attentions from the academia and industry. Recently, the fixation of CO₂ catalyzed by using four hydroxyl-functionalized ionic liquids (ILs) has been successfully achieved. However, the detailed mechanism is still ambiguous. We performed a theoretical study on the mechanism of the fixation of CO₂ catalyzed by 2-hydroxyl-ethyl-triethylammonium bromide (HETEAB) using the DFT method. The structural and energetic information for each possible route were obtained. Furthermore, the similarities and differences of two different catalysts, HETEAB and 2-hydroxyl-ethyl-tributylammonium bromide (HETBAB), were discussed in detail. In addition, the result shows that the OH functional group is one essential factor to improve the catalyst ability. Except that, including active H atom in the IL is the other major factor to refine the catalytic performance.

Li Wang;Ping Li;Xiangfeng Jin;Jinglai Zhang;Hongyan He;锁江 张

Journal of CO2 Utilization

2015-6-1

The confinement of Brønsted acidic 1-methyl-3-(3-sulfopropyl)-1H-imidazol-3-ium hydrosulfate ([PSMIm][HSO₄]) into the channel walls of two-dimensional (2D) COFs using a one-pot self-assembly strategy was achieved by incorporating an imine-linked TPB-DMTP-COF (TPB, triphenylbenzene; DMTP, dimethoxyterephthaldehyde) as the host. An appropriate loading of [PSMIm][HSO₄] is crucial for the BIL-COF hybrids to maintain proper geometry in the channel and sufficient acidic sites for the sorbitol substrate and sorbitan intermediate to enter and react. The best yield of isosorbide (97%) from sorbitol to date was obtained in the presence of BIL-COF-30 as the catalyst under optimized conditions. Besides, BIL-COF-30 can be recycled for at least five runs without activity loss.

Yi Ran Du;Bao Hua Xu;Jia Sheng Pan;Yi Wei Wu;Xiao Ming Peng;Yao Feng Wang;锁江 张

Green Chemistry

2019

Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. N-Allylquinolinium bromide under 365 nm UV exhibited intense green RTP emission with response upon adding chloroform. This interesting phenomenon endowed N-allylquinolinium bromide great potential as an anti-counterfeiting material.

Qingxia Xiong;Chao Xu;Nianming Jiao;Xiang Ma;Yanqiang Zhang;锁江 张

Chinese Chemical Letters

2019-7

Understanding the structural transition of ionic liquids (ILs) confined in a nanospace is imperative for the application of ILs in energy storage, gas separation, and other chemical engineering techniques. In this work, the quantitative relations between the properties and height of the nanochannel (H) for the ([Emim]⁺[TF₂N]^-) IL are explored through molecular dynamics simulations. Interestingly, the entropy of the confined IL exhibits a nonmonotonic behavior as H increases: initially increasing for H < 1.0 nm and then decreasing for 1.0 < H < 1.1 nm, followed by increasing again for H > 1.1 nm; it finally approaches that of liquid bulk ILs. The vibrational spectrum of the confined IL is analyzed to investigate the nature of nonmonotonic entropy, showing that the liquidity and partial solidity will be respectively attenuated and enhanced as H decreases from 5.0 to 0.75 nm. Moreover, the hydrogen bond (HB) network and external force are also calculated, showing similar nonmonotonic behaviors when compared with the thermodynamic properties. The entropy gain of the confined IL originates from the reduced HB interactions, weaker external force, and partial solid nature, where more phase space sampling for ILs inside a bilayer graphene nanochannel (BLGC) can be achieved. All the above relations demonstrate that there exists a critical height of the nanochannel (H_CR = 1.0 nm) at which the confined IL possesses weaker HB interaction, higher entropy, and better stability. The critical height of the nanochannel is also identified in the analysis of the local structures of cation head groups and anions, indicating that the confined IL could have a faster in-plane diffusive ability. These factors can serve as key indicators in quantitatively characterizing the mechanism for the structural transition of ILs inside a nanochannel and facilitate the rational design of nanopores and nanochannels to regulate the properties and structures of ILs in practical application scenarios.

Chenlu Wang;Yanlei Wang;Yumiao Lu;Hongyan He;Feng Huo;Kun Dong;Ning Wei;锁江 张

Physical Chemistry Chemical Physics

2019

Numerous binary catalysts of IL/Lewis acid have been developed for the coupling reaction of carbon dioxide and epoxides to form cyclic carbonates with high catalytic activity under benign environment. However, the mechanism is still obscure for most of catalysts. The catalytic mechanism of the binary catalysts hexaalkylguanidinium bromide/ZnBr₂ is elucidated by theoretical method in this work to obtain the reason of their high catalytic activity. Owing to the complicated of the binary catalysts, there are lots of possible attack forms. Finally, it is confirmed that the electrophilic attack from the Zn complex and the nucleophilic attack from the Br^- anion are the essential factors to promote the ring opening of PO. Following the most favorable route, the catalytic activity of different binary catalysts, including the ILs/ZnBr₂ and NBu₄Br/Zn(salphen), is compared. Moreover, the influence of the bulk of hexaalkylguanidinium salt on the catalytic activity is studied. The catalytic activity is enhanced with the increased bulk of the hexaalkylguanidinium salt. It is expected that our theoretical study would provide valuable clues to further refine the binary catalysts.

Li Wang;Tengfei Huang;Ci Chen;Jinglai Zhang;Hongyan He;锁江 张

Journal of CO2 Utilization

2016-6-1

Retorting oil shale produces shale oil, spent shale, retorting gas and water. On the basis of advantages offered by the fluidized bed retorting technology in comparison with ordinary retorting technologies of oil shale, fluidized bed oil shale retorting process to produce hydrogen and high valued hydrocarbon fuels (HVHFs) products is simulated and analyzed in this work. An integrated process scheme is designed in this work for hydrogenation of shale oil which consists of ebullated-bed catalytic reactor (EBCR) hydrogenation unit and two stage fixed bed catalytic reactors (FBCRs) hydrogenation unit. Four different scenarios are simulated and compared with respect to the end products and the energy efficiencies (HHV %) of the systems. The results indicate that the fourth scenario has least energy efficiency of the system (38.58% (HHV) of oil shale energy is stored in products, 36.13% (HHV) in HVHFs and 2.45% (HHV) in hydrogen) but provides the most important required end products as hydrogen (1.87 wt. %), middle distillate (68.97 wt. % (>80 wt. % diesel)), LPG (1.36 wt. %), naphtha (9.98 wt. %) and LSFO (19.21 wt. %). The whole system is modeled and simulated in the Aspen Plus V8.4 and the results are compatible with the industrial and experimental data. The sensitivity analyses are carried out to show the effects of various key operating parameters on the production of shale oil, retorting gas and hydrogen respectively.

Muhammad Afzal Raja;Hao Chen;Yongsheng Zhao;Xiangping Zhang;锁江 张

International Journal of Hydrogen Energy

2017-2-23

Ionic liquids (ILs) have attracted considerable attention in both the academic and industrial communities for absorbing and separating gases. However, a data-rich and well-structured systematic database has not yet been established, and screening for highly efficient ILs meeting various requirements remains a challenging task. In this study, an extensive database of estimated Henry's law constants of twelve gases in more than ten thousand ILs at 313.15 K is established using the COSMO-RS method. Based on the database, a new systematic and efficient screening method for IL selection for the absorption and separation of gases subject to important target properties is proposed. Application of the database and the screening method is highlighted through case studies involving two important gases separation problems (CO₂ from CH₄ and C₂H₂ from C₂H₄). The results demonstrate the effectiveness of using the screening method together with the database to explore and screen novel ILs meeting specific requirements for the absorption and separation of gases.

Yongsheng Zhao;Rafiqul Gani;Raja Muhammad Afzal;Xiangping Zhang;锁江 张

AICHE Journal

2017-4-1

The use of fuel additive has been proposed as a cost-effective strategy for leading to improvement in the fuel efficiency and reduction in the emissions from diesel-powered engines. This paper reports the results of experimental investigations on the influence of the addition of multi-composite naphthenates. The major physicochemical properties, engine performance and emissions of the base diesel and the modified diesel are measured. Comparisons of the performance of the diesel with and without the additive, both of them had good stability. The flash point and the viscosity were found that there was no change with the inclusion of the additive. The calorific value of diesel with additives has a significant increasing. The emission levels of NOx are appreciably reduced with the addition of multi-composite naphthenates. Therefore, it was concluded that the multi-composite naphthenates fuel additive can be used to improve the fuel properties of diesel.

Yong Chen;Hui Zhao;锁江 张;Guang Jin Zhang

2014