Superhydrophobic zeolitic imidazolate framework with suitable SOD cage for effective CH4/N2 adsorptive separation in humid environments

Various adsorbents for CH₄/N₂ separation were developed to enrich low-concentration coal-mine methane. Most are hydrophilic and cannot treat moist coal-mine methane. We report for the first time a microporous zeolitic imidazolate framework Co(dcIm)₂ (TUT-100) with superhydrophobic properties for CH₄/N₂ separation. The CH₄ adsorption capacity and CH₄/N₂ selectivity were as high as 45.29 cm³/cm³ and 6.3 (298 K, 1 bar), respectively, which results from the suitable SOD cage size (0.80 nm). The H₂O adsorption was lower than 6.3 cm³/g at 298 K and near saturated pressure due to the hydrophobic group  Cl. Breakthrough experiments were carried out to indicate the significant potential for CH₄/N₂ adsorption separation in a humid environment. The adsorption behavior of the gas mixture on the TUT-100 was investigated by the Grand Canonical Monte Carlo method and coupled with the experimental data.     

芳香硝基化合物还原方法的研究进展

综述了各种芳香硝基化合物还原制备相应苯胺方法的研究进展,尤其总结了在CO2-H2O体系中绿色、环境友好的还原硝基物制备相应芳胺的新方法,并对各种方法的应用前景进行了评价。     

Solubility of tri-iso-amyl phosphate in supercritical carbon dioxide and its application to selective extraction of uranium

The solubility of tri-iso-amyl phosphate (TiAP) in supercritical carbon dioxide (SCCO₂) was determined at 313–333 K with pressure ranging from 10 to 25 MPa. The solubility data of TiAP in SCCO₂ medium were correlated using four semi-empirical models. Selective extraction of uranium from simulated dissolver solution was demonstrated using SCCO₂ modified with TiAP. The extraction efficiency of uranium was found to be 95 ± 5%. The influence of temperature, pressure and acidity on the extraction of uranium was studied. An attempt was made to explain the plausible extraction mechanism.     

Synthesis and evaluation of aromatic polyamide membranes for desalination in reverse-osmosis technique

Reverse-osmosis membrane-grade aromatic polyamides have been synthesized by reacting 3,5-diaminobenzoic acid separately with three different acylchlorides, viz. isophthaloyl chloride, terephthaloyl chloride, and 4,4′-diphenyldicarboxylic acid chloride. Using these polyamides, asymmetric membranes were developed and characterized for various physical parameters, such as Staverman coefficient, membrane potential, and percent salt rejection using sodium chloride solution under high pressure. The effects of pressure, feed concentration, and feed flow rate have been studied on membrane transport parameters, viz. pure water permeability constant, product rate, solute transport parameter, and separation factor. The effects of annealing temperature and solvent evaporation time on the performance of the membranes were also studied. The analysis of the reverse-osmosis data revealed that the membranes prepared from the 3,5-diaminobenzoic acid and 4,4′-diphenyldicarboxylic acid chloride are superior to the membranes prepared from other polymeric materials. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 643–653, 1997     

螯合纤维对海水中铀的吸脱附性能研究

采用偕胺肟基螯合纤维对海水中的铀进行吸附,讨论了纤维制备条件对纤维吸附铀量的影响。结果表明:随着螯合纤维偕胺肟化时间的延长,纤维的吸附铀量增大;含偕胺肟基团的纤维经过碱水解后,纤维吸附铀量增大,适宜的碱处理时间为24 h;螯合纤维对铀的吸附量随着吸附时间的延长而逐渐增多,吸附时间超过48 h达到吸附饱和态,其饱和吸附量为2.6 mg/g。     

Evaluation of thermophysical data,COSMO-SAC predictions,and feed simplifications for aromatic extraction process simulation using ionic liquid [EMIM][NTf2]

Ionic liquids (ILs) are promising alternatives to conventional solvents for selective separation of aromatics from hydrocarbon mixtures, and their implementations depend on economic feasibility demonstrated by process simulation. Prior process modeling studies typically assume simplified hydrocarbon feeds or use the COSMO-SAC predictive model. Our goal is to evaluate how feed simplifications and COSMO-SAC predictions impact process modeling. We collect experimental data for 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]) from the ILThermo database to regress UNIQUAC model binary interaction parameters for 17 hydrocarbons. We find that feed simplifications tend to significantly underpredict process energy requirements and fail to reveal important details in the extractive distillation section of the process. COSMO-SAC predictions underpredict activity coefficient of aliphatics in [EMIM][NTf2] by a large margin, which leads to lower aromatic-aliphatic selectivities and overprediction of process energy requirements. It is significant enough to lead to the conclusion of process infeasibility in the case of [EMIM][NTf2].     

Comparison in the extraction behavior of uranium(VI) from nitric acid medium using CHON based extractants,monoamide, malonamide,and diglycolamide,dissolved in piperidinium ionic liquid

Liquid-liquid extraction of U(VI) from nitric acid medium was carried out using three different class of CHON based molecular extractants namely monoamide, malonamide, and diglycolamide present in 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide ([C₄mpip][NTf₂]) ionic liquid. The extractants investigated were di-n-hexyloctanamide (DHOA), N,N-dimethyl-N,N-di-octyl-2-(2-hexyloxylethyl)malonamide (DMDOHEMA) and N,N,N’,N’-tetra(ethylhexyl)diglycolamides (T2EHDGA). The extraction behavior of uranium(VI) in ionic liquid medium was investigated as a function of various parameters, such as the duration and temperature of equilibration, aqueous phase concentrations of feed acid, extractant, NaNO₃, and ionic liquid cation, etc. The extraction of U(VI) observed in these systems were compared with each other and the distribution ratios of U(VI) decreased in the order T2EHDGA > DMDOHEMA > DHOA. The slope analysis of the extraction data was carried out to understand the mechanistic aspects of extraction. The extraction of U(VI) observed in [C₄mpip][NTf₂] ionic liquid was also compared with pyrrolidinium ([C₄mpyr][NTf₂]) and imidazolium ([C₄mim][NTf₂]) based ionic liquids under identical experimental condition.     

Nucleosil Chiral-2 and Chiral-3手性柱在分离某些高效芳氧苯氧基丙酸酯类除草剂光学异构体中的应用

用实例叙述了Nucleosil Chiral-2和Chiral-3手性柱在分析某些高效芳氧苯氧基丙酸酯类除草剂光学异构体中的应用,说明了首选Chiral-3手性柱的理由,因为使用Chiral-2柱,上述除草剂的S．异构体（无效体）小峰往往出现在R-异构体（高效体）大峰的拖尾处,而不能被完全分离;使用Chiral-3手性柱,S-异构体小峰出现在R-异构体大峰前,而无此弊病。Chiral-2和Chiral-3手性柱也适用于苯氧丙酸类除草剂光学异构体的分离。     

New synthetic strategy for facile synthesis of functional polymers by one‐pot combination of controlled radical polymerization and enzymatic reaction

One‐pot synthesis in organic chemistry is deeply rooted in people's minds due to its huge improvement in efficiency compared with conventional stepwise synthesis. Nowadays, such a concept has also been shifted to polymer chemistry by one‐pot introducing compatible or orthogonal organic reactions with polymerizations for facilely synthesizing or modifying polymers. This review systematically summarizes recent developments in the one‐pot combination of enzymatic reactions with controlled radical polymerization to prepare functional polymers. © 2015 Society of Chemical Industry     

液晶高分子分子设计及合成方法的研究进展

综述了液晶高分子(LCP)分子设计的一般原则及其合成方法。着重介绍了热致主链型LCP、溶致主链型LCP及侧链LCP的分子设计与合成技术,并列举了国内外各种类型LCP的合成研究先例。     

Ice-templated assembly strategy to construct oriented porous Ti3SiC2 ceramics for thermal management and electromagnetic interference shielding in harsh thermal environments

Given the electromagnetic interference (EMI) and heat aggregation issue faced by electronic components, an urgent need exists to integrate EMI shielding and thermal conductivity in one material. Herein, a novel lightweight porous Ti₃SiC₂ ceramic with ordered structural arrangement was fabricated by using budget-friendly raw materials through ice template design and in-situ reaction synthesis. Leveraging the excellent conductivity and thermal conductivity of Ti₃SiC₂, a dual-functional advanced material with efficient EMI shielding and thermal management capabilities was obtained. At room temperature, porous Ti₃SiC₂ ceramics can achieve a shielding effectiveness of 35.44 dB and a thermal conductivity of 12.17 W/mK, with performance that can be tuned by porosity. In further, the porous Ti₃SiC₂ ceramic can work stably in thermal environments from room temperature to 700 °C or in corrosive environments rich in acid, alkali, and salts due to its excellent high temperature oxidation resistance and corrosion resistance. In view of the dual-functional characteristics and the stability of operation in harsh thermal environments, ordered porous Ti₃SiC₂ ceramics are promising for modern maritime and aerospace applications.     

A sensitive and selective deep eutectic solvent-based ultrasound-assisted liquid phase microextraction procedure for separation-preconcentration and determination of copper in olive oil and water samples

ABSTRACT

A green and simple deep eutectic solvent-based ultrasound-assisted liquid phase microextraction method has been developed for the preconcentration of copper as 2-(5-bromo-2-pyridylazo)-5-(diethylamino) phenol chelates. The effects of pH, ligand concentration, DES volume, sample volume, and tetrahydrofuran volume were investigated. Analytical performance parameters like limit of detection, limit of quantification, preconcentration factor, and relative standard deviation were determined as 6.6 μg L^?1, 21.8 μg L^?1, 15, and <5%, respectively. Validation of the developed method was checked by the analysis of certificated reference materials. The procedure was successfully applied to determination of copper in olive oil and water samples.     

New process development and process evaluation for capturing CO2 in flue gas from power plants using ionic liquid [emim][Tf2N]

Using the ionic liquid [emim][Tf_2N] as a physical solvent, it was found by Aspen Plus simulation that it was possible to attempt to capture CO_2 from the flue gas discharged from the coal-fired unit of the power plant.Using the combination of model calculation and experimental determination, the density, isostatic heat capacity,viscosity, vapor pressure, thermal conductivity, surface tension and solubility of [emim][Tf_2N] were obtained.Based on the NRTL model, the Henry coefficient and NRTL binary interaction parameters of CO_2 dissolved in[emim][Tf_2N] were obtained by correlating [emim][Tf_2N] with the gas–liquid equilibrium data of CO_2. Firstly,the calculated relevant data is imported into Aspen Plus, and the whole process model of the ionic liquid absorption process is established. Then the absorption process is optimized according to the temperature distribution in the absorption tower to obtain a new absorption process. Finally, the density, constant pressure heat capacity,surface tension, thermal conductivity, and viscosity of [emim][Tf_2N] were changed to investigate the effect of ionic liquid properties on process energy consumption, solvent circulation and heat exchanger design. The results showed that based on the composition of the inlet gas stream to the absorbers, CO_2 with a capture rate of 90% and a mass purity higher than 99.5% was captured. These results indicate that the [emim][Tf_2N] could be used as a physical solvent for CO_2 capture from coal-fired units. In addition, the results will provide a theoretical basis for the design of new ionic liquids for CO_2 capture.