SEPARATION AND PURIFICATION TECHNOLOGY
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2015
·
IF 3.091
Li-rong Nie,Jing Lu,Wei Zhang,Ai He,Shun Yao
In this work, six kinds of different ionic liquid-modified silica were synthesized and characterized with infrared spectroscopy, thermogravimetric analysis, elemental analysis, N 2 adsorption–desorption isotherms and particle size distribution. Then they were used as adsorbents for the preparative separation of water-soluble phenolic acids from Salvia militiorrhiza Bunge for the first time. The effects of various parameters including functional groups of adsorbents, adsorption time, initial concentration, solid–liquid ratio and temperature were investigated in detail. It was found that silica modified with N -methylimidazolium hexafluorophosphate (SiO 2 ·Im + ·PF 6 − ) had most excellent adsorption capacity for target compounds, which reached 99.81 mg/g under the conditions of adsorption time of 30 min, initial sample concentration of 350 mg/L and solid–liquid ratio of 1:1 (mg/mL). Studies showed that the equilibrium data fitted well with Langmuir model of adsorption and the adsorption kinetics was more accurately described by pseudo-second-order model. Thermodynamics parameters including the change of enthalpy, entropy and Gibbs free energy were also analyzed. Furthermore, the water-soluble phenolic acids of Salvia militiorrhiza Bunge were successfully preparatively separated on the normal pressure chromatographic column packed with the SiO 2 ·Im + ·PF 6 − particles to obtain protocatechuic aldehyde, sodium danshensu, rosmarinic acid, lithospermic acid and salvianolic acid B successively. The separation mechanism was investigated on the basis of experimental results and the reusability of the ionic liquid-modified silica gel was also explored. This study provides an useful reference for the preparation separation of natural products and indicates that the ionic liquid-modified silica can be applied in the separation of water-soluble phenolic acids with great prospects.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 22
·16847-16855
·
IF 3.84
Jun Xiong,Wenshuai Zhu,Wenjing Ding,Lei Yang,Ming Zhang,Wei Jiang,Zhen Zhao,Huaming Li
Hydrogen peroxide is usually used as an oxidant in oxidative desulfurization. However, in order to reach a high level of sulfur removal, excess of hydrogen peroxide needs to be added into the oxidative system. In this study, phosphomolybdic acid immobilized on imidazole-based ionic liquid modified mesoporous SBA-15 (HPMo-IL/SBA-15) was prepared. The as-prepared material combines the advantages of H3PMo12O40 (HPMo) and SBA-15. The high special surface area of SBA-15 could well disperse the HPMo active species. The results show that HPMo could be steadily immobilized across the surface of SBA-15 by using an imidazole-based ionic liquid. At the same time, after the introduction of the imidazole-based ionic liquid, HPMo-IL/SBA-15 material exhibited hydrophobic property. Experiments demonstrated that the hydrophobic catalyst exhibited a high activity in oxidative desulfurization. When hydrogen peroxide with a stoichiometric ratio (H2O2/sulfur mole ratio is 2) was used, the removal of dibenzothiophene (DBT) could achieve levels of above 90% at 60 °C in 90 min. When the concentration of hydrogen peroxide was slightly increased (H2O2/sulfur mole ratio increased from 2 to 2.5), the sulfur removal reached 100% in 40 min. Moreover, the synthesis catalyst could adsorb dibenzothiophene sulfone (DBTO2), which is the oxidant product of DBT. In this regard, HPMo-IL/SBA-15 served as not only a high-efficiency catalyst but also an adsorbent.
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ADVANCES IN POLYMER TECHNOLOGY
·
2015
·Vol. 36
·期 2
·220-229
·
IF 1.045
Xiaoming Zhang,Wenming Yang,Ningwei Wang,Xiaoni Ni,Huajie Wang,Zhaoyang Gu,Xiangyang Wu,Wanzhen Xu
New ionic liquid-mediated molecularly imprinted polymers (ILMIPs) for phthalate esters were developed in this study by the situ thermal polymerization method using methacrylic acid as a functional monomer and dibutyl phthalate (DBP) as a template. The polymer was characterized by scanning electron microscopy and Fourier transform infrared spectrometry. Batch static binding adsorption experiments were carried out to analyze its adsorption performance. The selectivity and adsorption of molecularly imprinted polymers were improved by the ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate as an excellent auxiliary porogen and solvent. The adsorption process conformed to pseudo–first-order model by kinetics analysis and Sips model by isotherm analysis. Using the prepared ILMIPs as a solid-phase extraction (SPE) sorbent, which indicated that ILMIPs–SPE had a higher enrichment efficiency and a better selectivity for DBP, and the average recoveries of DBP at four spiked levels were in a range of 96.4–101.3% ( n = 5) with relative standard deviation (RSD) ≤6.9%.
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DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 22
·7210-7218
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IF 4.029
Wenhui Liu,Qi Wang,Yan Zheng,Shubin Wang,Yan Yan,Yanzhao Yang
In this study, a method of one-step separation and recycling of high purity Pd(II) and Pt(IV) using an ionic liquid, 1-butyl-3-benzimidazolium bromate ([HBBIm]Br), was investigated. The effects of [HBBIm]Br concentration, initial metal concentration, and loading capacity of [HBBIm]Br were examined in detail. It was observed that [HBBIm]Br was a very effective extractant for selectively extracting Pd(II) and precipitating Pt(IV). Through selectively extracting Pd(II) and precipitating Pt(IV), each metal with high purity was separately obtained from mixed Pd(II) and Pt(IV) multi-metal solution. The method of one-step separation of Pd(II) and Pt(IV) is simple and convenient. The anion exchange mechanism between [HBBIm]Br and Pt(IV) was proven through Job's method and FTIR and 1H NMR spectroscopies. The coordination mechanism between [HBBIm]Br and Pd(II) was demonstrated via single X-ray diffraction and was found to be robust and distinct, as supported by the ab initio quantum-chemical studies. The crystals of the [PdBr2 ·2BBIm] complex were formed first. Moreover, the influence of the concentrations of hydrochloric acid, sodium chloride, and sodium nitrate on the precipitation of Pt(IV) and extraction of Pd(II) was studied herein. It was found that only the concentration of H+ could inhibit the separation of Pt(IV) because H+ could attract the anion PtCl62−; thus, the exchange (anion exchange mechanism) between the anions PtCl62− and Br− was prevented. However, both the concentration of H+ and Cl− can obviously inhibit the extraction of Pd(II) because H+ and Cl− are the reaction products and increasing their concentration can inhibit the progress of the reaction (coordination mechanism).
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PubMed
高影响因子
Journal of Water Chemistry and Technology
·
2024
·Vol. 46
·期 5
·480-490
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IF 0.5
Yaqi Liu,Han Quan,Huo Yanyan,Yang Xiaohui
Abstract A new method for the determination of ultra-trace cobalt by ionic liquid-dispersive liquid-liquid microextraction (IL-DLLME) and graphite furnace atomic absorption spectrometry (GFAAS) was developed. The trace cobalt was extracted by DLLME using the homemade reagent 2-(5-bromo-2-pyridylazo)-5-dimethylaminobenzenamine (5-Br-PADMA) as chelating agent, the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([C 6 mim][PF 6 ]) as extractant, and acetonitrile (CH 3 CN) as dispersing agent, and then determined by GFAAS. The factors affecting the cobalt extraction efficiency: the type and volume of extraction solvent and dispersive solvent, the concentration and dosage of chelating agent, and the pH of the solution, were explored using the one-way rotation method. Under the optimized conditions, the cobalt concentration showed excellent linearity in the range of 0.05–1.50 ng/mL with the detection limit of 0.026 ng/mL; the relative standard deviation (RSD) for the determination of the cobalt standard solution with the mass concentration of 1.0 ng/mL was 4.83% ( n = 9). From the slope of the linear regression equation for the determination of cobalt obtained after extraction compared with that before extraction, the enrichment factor of the method was found to be 62, and the spiked recoveries were in the range of 94.0–104.4%. The method is characterized by low detection limit, high sensitivity, and environment friendliness as well as convenient and rapid operation for the determination of trace cobalt in water samples. The results of this method are satisfactory.
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Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yuqiao Jiang,Xinyu Yuan,Peiru Wang,Linyan Cheng,Ranran Li,Qinghua Qu,Cheng Fang,Hongping Li,Jing Ding,Hui Wan,Guofeng Guan
The elimination of carbon dioxide (CO 2 ) from the industrial post-combustion dilute CO 2 has been a hot issue and the selective conversion of CO 2 from the exhaust gas stream still remains a challenge. Herein, dihydroxy functionalized binuclear carbonate based poly(ionic liquid)s (HB-PILs) were prepared for conversion of low-concentration CO 2 from the dilute CO 2 (15 vol% CO 2 + 85 vol% N 2 ) into cyclic carbonate. Using epichlorohydrin as a probe substrate, the obtained HB-PILs exhibited excellent catalytic performance for the CO 2 cycloaddition reaction. Under optimized process parameters (100 ℃, 2 MPa and 4 h), the highest yield (95 %) of chloropropene carbonate (CPC) was obtained, which was comparable to the previous reported results. Moreover, the synergetic effect between the activation of epoxides by dihydroxyl groups and the adsorption of CO 2 by basic CO 3 2- ions was studied through the theoretical calculations. DFT results indicated that CO 3 2- served as the nucleophilic site, working synergistically with hydrogen bond donors to facilitate the ring-opening of epichlorohydrin (ECH). Additionally, CO 3 2- functioned as the basic site to activate CO 2 . This study will provide a promising solution for mitigating global climate change and advancing the green chemistry of CO 2 utilization from dilute CO 2 .
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FUEL
·
2024
·
IF 6.7
Ran Liu,Chang Wang,Jingran Yang,Chen Liu,Liberty Mguni,Xinying Liu,Yali Yao,Fatang Li
There is a challenge with designing catalysts that simultaneously possess active sites for catalyzing the generation of reactive oxygen species (ROSs) and effectively overcoming mass transfer resistance in oil–water biphasic systems. In this study, a novel, highly efficient oxidative desulfurization (ODS) strategy is proposed that uses an ILs-loaded metal–organic framework (MOF) coupled material as a catalyst. The IL@MOF ([Hnmp]HSO 4 @MIL-125(Ti)) coupled material prepared by loading [Hnmp]HSO 4 onto MIL-125(Ti) has catalytic-adsorption synergistic capability. It demonstrated outstanding oxidative desulfurization performance by achieving nearly a 100 % removal of dibenzothiophene (DBT) from model oil with a dosage of 0.04 g IL@MOF per 10 mL of model fuel under mild conditions (50 °C, 10 min). By comparing the experimental results with the characterization data, it is suggested that [Hnmp]HSO 4 @MIL-125(Ti) converts superoxide radicals (•O 2 − ) into 1 O 2 through oxygen vacancies (Ov) and that the catalytic action of Ti on the oxidation of DBT is primarily based on a 1 O 2 -driven non-free radical mechanism. [Hnmp]HSO 4 @MIL-125(Ti) serves as a favorable medium for contact to be made between ROSs and sulfides, which indicates an efficient catalytic-adsorption synergy.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Zhencai Zhang,Zifeng Yang,Ming Jiang,Wenjuan Fang,Heng Wang,Chenhao Li,Xin Yao,Zengxi Li,Fei Xu
The utilization of biomass to produce plastic is one of the key ways to minimize the negative impacts of climate change and alleviate the depletion of petroleum resources. However, there is still a lack of bioderived polymers with properties comparable to those of commercial petroleum-based polymers. Isosorbide-based polycarbonate (PIC) is the most promising substitute for traditional petroleum-derived polycarbonate, but its application is still limited by the low reactivity and poor ductility of isosorbide. In this study, we developed a new strategy for designing functionalized ionic liquid catalysts enhanced by the cation–π interactions, and high performance isosorbide-based copolycarbonate was prepared. On the one hand, PIC with high weight-average molecular weight of 126,000 g/mol was synthesized by using 1-benzyl-3-methylimidazolium acetate ([Bnmim][OAc]) as a catalyst. This was attributed to the formation of stronger π–π interactions between the benzyl group and the imidazolium cation, which promoted the activation of carbonyl groups and overcame the low activity of isosorbide. Furthermore, to overcome the brittleness of PIC, the introduction of 1,10-decanediol into PIC provided not only copolycarbonates with an adequate elongation at break (121%), which was better than bisphenol A polycarbonate, but also copolycarbonates with a wide range of glass transition temperature (Tg 20–168 °C), expanding the application of PIC. This study provides an avenue for the development of excellent performance biobased polycarbonates using ionic liquid catalysts.
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RSC Advances
·
2024
·Vol. 14
·期 28
·20199-20209
·
IF 3.9
Yaping She,Xinyu Chen,Mengya Wang,Anqiu Liu,Xiaochen Wang,Daming Gao,Kunhong Hu,Miao Hu
Heterogeneous solvent-metal-free aerobic oxidation of alcohols under ambient conditions is interesting but remains a significant challenge. Herein, a series of porous TEMPO-functionalized poly(ionic liquid)s (TEMPO-PILs) featuring a pure polycationic framework were successfully developed through the free radical polymerization of the ionic liquid 3-(2-chloroacetic acid-2,2,6,6-tetramethyl-1-oxo-4-piperidyl)-1-vinylimidazolium chloride and bis-vinylimidazolium bromide salt. Characterizations revealed that the obtained TEMPO-PILs possessed a high TEMPO density, abundant bromide ions, and a tunable porous structure, which enabled them to serve as solvent-free heterogeneous organocatalysts for the metal-free aerobic oxidation of benzyl alcohol under ambient conditions, exhibiting high catalytic activity and stable recyclability. A high yield of 99% coupled with a turnover frequency (TOF) of 13.3 h−1 was obtainable, which is higher than most of the reported TEMPO-based heterogeneous catalysts, even superior to homogeneous TEMPO-functionalized ionic liquids. Furthermore, a broad range of alcohols were effectively converted into their corresponding ketones and aldehydes. A possible reaction mechanism is proposed for understanding the catalytic oxidation behavior, indicative of the synergistic effect of TEMPO moieties and bromide ions.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Xianfeng Guan,Wanzhen Wu,Shuyu Zhang,Guangpeng Ma,Xinpu Zhou,Cuicui Li,Di Yu,Yu Luo,Shuang Wang
ABSTRACT Achieving the right balance between electrical conductivity and long-term reliability in high-temperature proton exchange membrane (HT-PEM) technologies contributes to sustainable energy recycling. This study involves a groundbreaking effort to create amphiphilic polybenzimidazoles by incorporating 2-isocyanatopyridine into hydroxy-polybenzimidazole (OHPBI). A high hydrogen-bond density network is constructed through two-by-two interactions between the hydroxyl group, the imidazole molecule and quaternary ammonium group. Quaternary ammonium polymeric ionic liquid is introduced to maintain high phosphoric acid (PA) doping and PA retention. The PA retention of the amphiphilic polybenzimidazole membrane is 87.5% after 240 h at 160 °C/0% RH. Furthermore, the peak power density of the amphiphilic polybenzimidazole membrane reach 837.8 mW cm -2 at 180 °C and the voltage decay rate is 0.23 mV h -1 after long-term operation. More specifically, the amphiphilic polybenzimidazole membranes show a conductivity of 138.9 mS cm -1 at 180 °C. This indicates that the amphiphilic polybenzimidazole membrane has both high power output and long-term stability. This work introduces an innovative method to improve the efficiency of PBI-based HT-PEM.
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ACS Applied Polymer Materials
·
2024
·
IF 4.4
Yaojie Yan,Xiaozhi Zhang,Yi Wang,Shenghua Xue,Shujuan Liu,Qian Ye,Feng Zhou,Weimin Liu
Recently, a variety of functionalization methods have emerged to enhance the application efficiency of covalent organic frameworks (COFs) across diverse fields. Herein, poly(ionic liquid)-functionalized COF-LZU1 was successfully synthesized via a mechanochemical reaction followed by surface-initiated ring-opening metathesis polymerization (SI-ROMP). At first, a ROMP initiator (5-norbornene-2-methylamine) was grafted onto the aldehyde-terminated COF-LZU1 via Schiff base reaction induced by mechanical force input through ball milling; subsequently, the ionic liquid monomer (NM-MIm-PF6) can grow onto the surfaces of COFs from the active sites of the initiator through SI-ROMP, resulting in the formation of a poly(ionic liquid)-functionalized COF (PNM-MIm-PF6@LZU1). The as-prepared PNM-MIm-PF6@LZU1 exhibited outstanding tribological performance when served as an oil-based lubricant additive. Compared to base oil 500SN, the average friction coefficient of the lubricant with PNM-MIm-PF6@LZU1 decreased from 0.162 to 0.105, accompanied by a 74.3% reduction in wear volume. The excellent lubricating performance is mainly attributed to the formation of a continuous and tough friction protective film through tribochemical reaction on the friction interface.
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Nanoscale
·
2024
·
IF 5.8
Shoujie Shen,Qiyu Wu,Xingchao Chen,Jia Li,Xuanting Zhao,Chuao Ma,Chan Liu,Hongliang Liu
Stretchable transparent electrodes (STEs) composed of highly conductive silver nanowires (AgNWs) and mechanically stretchable polydimethylsiloxane (PDMS) are compelling materials for the development of flexible electronic devices. So far, the fabrication processes of the AgNWs/PDMS-based STEs suffer from low efficiency on a small scale, apart from the limitations and challenges posed by the continuous fabrication processes that are required to exploit these fascinating materials in an industrial context. Here, we have addressed these limitations by using gradient PDMS with a tunable modulus as the stretchable substrate, on which ionic liquid-mediated aligned semi-embedded AgNWs are formed via a scalable superwettability-induced transfer strategy. We have demonstrated the importance of the gradient PDMS in achieving STEs with improved optoelectrical properties, mechanical stretchability, and long-term stability. Furthermore, we have shown the applications of the designed STEs for electro-heating and electroluminescent devices. This promising fabrication process is an industrially relevant alternative to current processes that are either complicated and less effective (for example, stamping transfer) or not compatible with continuous, large-scale production (for example, spin-coating or electrospinning).
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