JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2016
·Vol. 92
·期 7
·1785-1793
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IF 2.738
Jiandong Cui,Tao Lin,Yuxiao Feng,Zhilei Tan,Shiru Jia
BACKGROUND Cross-linking enzyme aggregates (CLEAs) seem to be a promising immobilization method due to mild processing conditions and short preparation time. However, the CLEAs prepared in aqueous solution exhibit amorphous large clusters that cause significant mass-transfer limitations, leading to low catalytic efficiency. In this work, novel spherical CLEAs of lipase from bovine pancreas (spherical CLEAs) were prepared within droplets dispersed in a water-in-hydrophobic ionic liquid microemulsion rather than a conventional aqueous solution. The properties of the spherical CLEAs were determined. RESULTS The resultant CLEAs exhibited spherical structure with good monodispersity instead of the amorphous clusters of conventional CLEAs, and showed higher activity recovery (84.6%) than that of conventional CLEAs (52.8%). The high activity recovery of spherical CLEAs could be attributed to both interfacial activation of the microemulsion system and the well-defined structure of the spherical CLEAs, which not only activated lipases in an active form, but also decreased mass-transfer limitations. Moreover, the thermostability, storage stability, tolerance against hydrophilic solvents, and mechanical stability of the spherical CLEAs were enhanced significantly. The spherical CLEAs evidenced excellent reusability in comparison with conventional CLEAs. CONCLUSIONS The novel strategy in this study might open an attractive way towards effectively improving the catalytic properties of traditional CLEAs. © 2016 Society of Chemical Industry
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高影响因子
RSC Advances
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2016
·Vol. 6
·期 115
·114572-114579
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IF 3.289
Youhong Ai,Mian Wu,Liu Yang,Faqiong Zhao,Baizhao Zeng
A polyaniline (PANI)-ionic liquid (IL) based solid phase microextraction (SPME) coating is presented. The porous PANI was electrodeposited on a stainless steel wire, and then it was coated with IL. The porous PANI could well immobilize IL, and the obtained hybrid coating could be used for more than 110-times of adsorption/desorption. The extraction efficiency of different ILs (i.e. 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate and 1-(2-hydroxyethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HOEMim]NTf2)) based coatings was compared for different analytes (i.e. benzene, aryl halide, phenolic, amine and fatty alcohol compounds). It was found that the PANI-[HOEMim]NTf2 coating exhibited quite high extraction efficiency for fatty alcohol compounds (i.e. 1-octanol, 1-nonanol, n-decanol, 1-undecanol and dodecanol). The dependence of the gas chromatograph peak areas of the analytes after SPME on their initial concentration in solution was investigated and the corresponding isothermal adsorption equation was displayed. After optimizing the conditions, linear detection ranges of 0.05 ng mL−1 to 100 ng mL−1 were obtained for different fatty alcohol compounds. The limits of detection were 0.0061–0.018 ng mL−1. The relative standard deviations (RSD) of the peak area were below 8.4% for five repetitive extractions of solutions containing 25 ng mL−1 fatty alcohol compounds. The proposed method was applied to the determination of the analytes in two tea drinks, and 57 ng mL−1 of 1-nonanol was found in a jasmine tea sample, while 2.2 ng mL−1 of 1-undecanol was found in a rock sugar lemon sample, but other analytes were below their detection limits. The recoveries for spiked fatty alcohols were 84.9–117.6%, and the RSDs were lower than 12.2%.
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Journal of Materials Chemistry A
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2017
·Vol. 5
·期 28
·14630-14638
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IF 8.867
Qingqing Miao,Suojiang Zhang
A new series of soft materials were successfully achieved by a simple synthetic method in water. The coordination reactions of task-specific ionic liquid with different metal oxides were systematically investigated and analyzed. The obtained ten ionic liquid–metal complexes (ILMCs) were developed for efficient electrolytes for dye-sensitized solar cells (DSCs). ILMC-based DSCs exhibit superior photovoltaic performance and the remarkable increases in efficiencies with a multiple of 1.46–2.63 compared with an ionic liquid (IL) electrolyte without a metal center. The mechanism investigations clarified the influences of different metal centers on the conversion efficiencies of the corresponding devices. The high conductivity and diffusion coefficient of I3−, inhibited electron recombination and low charge transfer impedance contribute to the superior photovoltaic performance of ILMC electrolytes. The new concept, simple composition, high conductivity and conversion efficiency along with an easy fabrication method qualify the ILMC-based soft materials as promising high-efficient alternative electrolytes of DSCs.
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RSC Advances
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2016
·Vol. 6
·期 99
·96768-96777
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IF 3.289
Yuhao Chu,Yuenan Chen,Nanjun Chen,Fanghui Wang,Hong Zhu
Recently a new method for increasing the ion conductivity of anion exchange membranes (AEM) was developed based on the novel materials ionic liquids (ILs). We mixed the ILs into the membrane directly instead of immobilizing onto the polymer backbone as in the traditional way. Nano-TiO2 was introduced to stabilize the ILs in the membrane. The ILs were immobilized by the nano-TiO2, acting as the “active sites” in the membrane, to enhance the mobility of the hydroxyl groups so as to increase the ion conductivity. Both pure ILs composite membranes and ILs–TiO2 composite membranes were synthesized, and their properties were compared. 1H nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy were used to analyze the structures of the composite membranes. The mechanical properties, thermal stabilities, ion conductivities, water uptakes, swelling ratios, and ion exchange capacities of the membranes were investigated. The interaction between the TiO2 and ionic liquids was confirmed by X-ray diffraction. The stability of the ILs in the membrane was measured comprehensively. All these results show that this novel method is effective and promising for AEM applications.
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高影响因子
LANGMUIR
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2017
·
IF 3.833
Lan Ma,Hui Tang,Peiyi Wu
The microdynamic volume phase transition mechanism of poly[di(ethylene glycol)ethyl ether acrylate] (PDEGA)-based microgels with newly developed thermoresponsive polyionic liquid (PIL) (poly(tetrabutylphosphonium styrenesulfonate) P[P4,4,4,4][SS]) moieties was studied by applying temperature-variable Fourier transform infrared (FTIR) spectroscopy in combination with two-dimensional correlation spectroscopy (2Dcos) and the perturbation correlation moving window (PCMW) technique. It can be found that the content of hydrophilic PIL moieties plays a significant role in the thermally induced phase transition behavior of microgel systems; namely, the microgels containing fewer PIL moieties present a sharp transition behavior and a gel-like state (10%, w/v) in water whereas the microgels with more PIL moieties undergo a slightly broad phase transition process and a flowable solution state. Herein, the C═O···D2O-PIL hydrogen bonds as the interaction between PDEGA and P[P4,4,4,4][SS] moieties result in a complete dehydration process for the microgels with fewer PIL moieties and the dehydrated behavior of SO3– groups acts as the driving force during the phase transition. As for the microgels with more PIL moieties, the whole transition process is dominated by the hydrophobic interaction of C–H groups. Even though the intermolecular hydrogen bonds (C═O···D2O-PIL) appear as well, the more remarkable effect of the Coulombic repulsive force of PIL restrains the water molecules from breaking away, thus causing a gradual and incomplete dehydration process during heating.
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PubMed
高影响因子
RSC Advances
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2017
·Vol. 7
·期 8
·4704-4709
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IF 3.108
Lijuan Zhao,Juan Yang,Huili Ye,Faqiong Zhao,Baizhao Zeng
A hydrophilic ionic liquid monomer (i.e. 1-(α-methyl acrylate)-3-vinylimidazolium bromide) was immobilized on carboxylated multi-walled carbon nanotubes (MWNTs) by ion exchange, then reversible addition–fragmentation chain transfer precipitation polymerization (RAFTPP) was performed in the presence of a template, imidacloprid. The obtained imidacloprid imprinted material showed a netlike structure; it had a large surface and high adsorption capacity, and allowed rapid mass transfer. When it was supported on a 1-(3-aminopropyl)-3-methylimidazolium bromide functionalized-graphene (GR-IL) coated glassy carbon electrode, the resulting sensor presented a good electrochemical response to imidacloprid. After optimizing the preparation and determination conditions, a linear range of 0.2–24 μM with a sensitivity of 0.71 μA μM−1 mm−2 was obtained. The detection limit was 0.08 μM. The sensor also presented good selectivity and reproducibility. It was successfully applied to the determination of imidacloprid in practical samples and the recovery for the standards added was 94–107%.
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RSC Advances
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2016
·Vol. 6
·期 111
·110247-110254
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IF 3.289
Xiaojun Wang,Guoliang Xu,Peng Chen,Xueying Liu,Ye Fang,Siyu Yang,Guozhen Wang
A novel magnetic ionic liquid-based air-assisted liquid–liquid microextraction (MIL–AALLME) technique was developed for highly selective separation of trace amounts of arsenite and arsenate species in various environmental water, sediment and soil samples prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS). This highly efficient separation method combines the advantages of magnetic ionic liquid (MIL) and air-assisted liquid–liquid microextraction (AALLME) for the first time. The MIL, 1-butyl-3-methylimidazolium tetrachloroferrate ([C4mim][FeCl4]), was used as the extractant to simplify the microextraction procedure by magnetic separation. The variables of interest in the MIL–AALLME method, such as pH values, amounts of chelating agent, types and amounts of MIL, salt effect and number of extraction cycles were assessed and optimized systematically. Under optimal extraction conditions, the MIL–AALLME method provided a good linear dynamic range (LDR) in the range of 0.04–10.0 μg L−1 and the determination coefficient was 0.9991. Using the present method, the limit of detection (LOD) and the relative standard deviation (RSD) for seven replicate measurements of 2.0 μg L−1 of As(III) was 0.029 μg L−1 and 2.5%, respectively. The developed methodology was successfully used for inorganic arsenic speciation studies in different environmental water, sediment and soil samples with satisfactory results ranging from 93.0 to 108.5% for the spiked samples. In order to confirm the accuracy of MIL–AALLME, five standard reference materials such as GBW08605 simulated natural water and GBW07309 sediment were analyzed, and the analyzed values found by using the present methodology were in statistic agreement with the certified values.
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Journal of Water Chemistry and Technology
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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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CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2017
·
IF 0.795
Xing-Li PEI,Yu-Yu HUANG,Can GONG,Xu XU
The ionic liquid butylamine 2,5-dihydroxybenzoate (DHB-BuN) was chosen as the matrix for improving reproducibility of oligosaccharides quantification, and imaging oligosaccharides in soybean and leaf by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). In the experiment, ionic liquid matrix of methanol solution (20%, V/V ) was simply covered onto the sample slice, and MS imaging experiment was thus performed to analyze oligosaccharides and their distribution in soybean and soybean leaf in positive ion mode with laser power of 70%. As a result, the MALDI-MS analysis of three oligosaccharides including sucrose, raffinose and stachyose was performed using the ionic liquid matrix, and the reproducibility RSD was less than 3% for in-spot and less than 4% for spot-to-spot. The linear correlation coefficients ( R 2 ) of standard curves between MS peak intensity and oligosaccharides concentrations raging from 0.062 mg mL −1 to 1.00 mg mL −1 were all no less than 0.996, which showed a great potential in quantitative analysis of oligosaccharides by MALDI-MS. The matrix was then used for the imaging analysis of disaccharide, trisaccharide and tetrasaccharide on the surfaces of soybean chip and soybean leaf by MALDI-MS, and the mass spectrometric imaging of the three kinds of oligosaccharides was obtained with a spatial resolution of 150 μm. The result indicated that the distribution of three kinds of oligosaccharides in the soybean was roughly homogeneous, and mostly at its tip part in the leaf. The contents of the three oligosaccharides could be estimated by their MS peak intensity and above standard curve. This study suggested that the ionic liquid DHB-BuN matrix could be well applied in MALDI-MS imaging analysis of oligosaccharides in different samples.
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RSC Advances
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2024
·Vol. 14
·期 28
·20199-20209
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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
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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
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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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危险品化学品经营许可证（带存储）