RSC Advances
·
2014
·Vol. 4
·期 63
·33466-33473
·
IF 3.708
Qing Wang,Zhi Min Wu,Yongfei Li,Ying Tan,Ning Liu,Yuejin Liu
The efficient hydroxyalkylation of phenol with formaldehyde to bisphenol F over a thermoregulated phase-separable reaction system containing a water-soluble Brønsted acidic ionic liquid was studied. The reaction system containing the water-soluble IL showed thermoregulated biphasic behavior with change of the alkyl chain length of IL, temperature and water amount. Four types of imidazolium-, ammonium-, phosphonium- and pyridinium-based water-soluble ionic liquids with different anions of dihydrogen phosphate [H2PO4]−, acetate [CH3COO]− and hydrogen sulfate [HSO4]− were used as both Brønsted acidic catalysts and thermoregulated solvents. Among them, [C6MIM][HSO4] gave a high yield of 80.5% and a selectivity of 96.9% for bisphenol F, and the optimal reaction conditions were stirring speed 450 rpm, phenol–formaldehyde ratio 6 : 1, IL catalyst molar concentration 12.5%, reaction temperature 90 °C and reaction time 1 h. [C6MIM][HSO4] could be recovered by simple decantation and could retain its original activity even after six recycling-uses [CnMIM][HSO4] with the alkyl chain length n = 6 found to be the most suitable for the synthesis of bisphenol F because of both the formation of a thermoregulated monophasic reaction system at 90 °C to enhance the reaction efficiency and as a thermoregulated phase-transition solvent to facilitate its recovery from the reaction system.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2014
·Vol. 406
·期 18
·4563-4569
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IF 3.578
Xie Qilong,Liu Shuhui,Fan Yingying,Sun Jianzhi,Zhang Xiaoke
A selective and low organic-solvent-consuming method of sample preparation combined with high-performance liquid chromatography with diode-array detection is introduced for analysis of phthalic acid esters in edible oils. Sample treatment involves initial liquid–liquid partitioning with acetonitrile, then QuEChERS cleanup by dispersive solid-phase extraction with primary secondary amine as sorbent. Preconcentration of the analytes is performed by ionic-liquid-based dispersive liquid–liquid microextraction, with the cleaned-up extract as disperser solvent and 1-hexyl-3-methylimidazolium hexafluorophosphate as extraction solvent. Under the optimized conditions, correlation coefficients ( r ) were 0.998–0.999 and standard errors ( S
y / x
) were 2.67–3.37 × 10 3 for calibration curves in the range 50–1000 ng g −1 . Detection limits, at a signal-to-noise ratio of 3, ranged from 6 to 9 ng g −1 . Intra-day and inter-day repeatability, expressed as relative standard deviation, were in the ranges 1.0–6.9 % and 2.4–9.4 %, respectively. Recovery varied between 84 % and 106 %. The developed method was successfully used for analysis of the analytes in 28 edible oils. The dibutyl phthalate content of four of the 28 samples (14 %) exceeded the specific migration limit established by domestic and international regulations.
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PubMed
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Food Analytical Methods
·
2016
·Vol. 10
·期 6
·1745-1754
·
IF 2.167
Wang Meng,Yang Fan,Liu Le,Cheng Chunsheng,Yang Yaling
A highly selective sample cleanup procedure combining ionic liquid-based surfactant extraction (ILSE) and magnetic dispersive μ-solid phase extraction (MD-μ-SPE) was triumphantly developed for the synchronously extraction of four phthalate acid esters (PAEs) in packaging milk samples prior to high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD). In this ionic liquid (IL)-based surfactant method, 1-octyl-3-methylimidazolium hexafluorophosphate ([C 8 MIM] [PF 6 ]) was used as extraction solvent, anionic surfactant sodium linear alkylbenzene sulfonate (LAS) was used as auxiliary extraction solvent, and then sodium chloride (NaCl) was mixed to drive phase separation. The synthesized hydrophobic diatomaceous earth-supported Fe 3 O 4 magnetic nanoparticles (DSMNPs) were applied as an efficient adsorbent to retrieve the analyte-containing IL and LAS. Under the optimal extraction situations, good linearity of the approach was obtained in the concentration range from 10 to 1000 ng/mL for target analytes, and the preconcentration process was rapidly accomplished in 5 min. The limits of detection (LODs) based on a signal-to-noise ratio (S/ N = 3) were ranged from 1.42 to 3.57 ng/mL with the relative standard deviations (RSDs) over the range of 1.84–3.56% ( n = 5). The above-mentioned method was applied to the trace analysis of four PAEs including benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), and di-n-octyl phthalate (DNOP) in packaging milk samples, and recoveries were between 89.8 and 99.7%.
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ChemSusChem
·
2017
·Vol. 10
·期 9
·2046-2052
·
IF 7.226
Tianxiang Zhao,Xingbang Hu,Dongsheng Wu,Rui Li,Guoqiang Yang,Youting Wu
Graphical We can do both : An imidazolium hydrogen carbonate ionic liquid can serve as both a recyclable catalyst (C) and dehydrant (D) for the direct synthesis of dimethyl carbonate (DMC) from CO 2 and CH 3 OH at room temperature (see scheme). A high conversion of CH 3 OH and excellent selectivity of DMC are obtained. The direct synthesis of dimethyl carbonate (DMC) from CO 2 and CH 3 OH was achieved at room temperature with 74 % CH 3 OH conversion in the presence of an imidazolium hydrogen carbonate ionic liquid ([C n C m Im][HCO 3 ]). Experimental and theoretical results reveal that [C n C m Im][HCO 3 ] can transform quickly into a CO 2 adduct, which serves as an effective catalyst and dehydrant. Its dehydration ability is reversible. The energy barrier of the rate-determining step for the DMC synthesis is only 21.7 kcal mol −1 . The ionic liquid can be reused easily without a significant loss of its catalytic and dehydrating ability.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2017
·
IF 3.154
Yehong Han,Chunliu Yang,Yang Zhou,Dandan Han,Hongyuan Yan
A new method involving ionic liquid–hybrid molecularly imprinted material–filter solid-phase extraction coupled to high-performance liquid chromatography (IL–HIM–FSPE–HPLC) was developed for the simultaneous isolation and determination of 6-benzyladenine (6-BA) and 4-chlorophenoxyacetic acid (4-CPA) in bean sprouts. Sample preconcentration was performed using a modified filter, with the new IL–HIM as the adsorbent, which shows double adsorption. The first adsorption involves special recognition of molecular imprinting, and the second involves ion exchange and electrostatic attraction caused by the ionic liquid. This method combines the advantages of ionic liquids, hybrid materials, and molecularly imprinted polymers and was successfully applied to determine 6-BA and 4-CPA in bean sprouts. The adsorption of 6-BA to IL–HIM is based on selective imprinted recognition, whereas the adsorption of 4-CPA is mainly dependent on ion-exchange interactions.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Runming Wang,Gang Cheng,Zan Dai,Jie Ding,Yunling Liu,Rong Chen
A general ionic-assisted microwave-ultrasonic combined synthetic strategy was developed to fabricate Bi 2 E 3 (E = S, Se, and Te) hierarchitectures. To understand the crystal phase transformation and morphological evolution of Bi 2 S 3 hierarchical nanostructures, the fabrication of Bi 2 S 3 hierarchitectures was investigated by varying sulfidation time and chlorination time. A topotactic transformation from BiOCl microsphere to Bi 2 S 3 hierarchitectures was proposed. It was found that the structure, size, and morphology of Bi 2 S 3 hierarchitectures could be delicately engineered by varying chlorination time, alkyl chain length, and concentration of ionic liquid. Moreover, the as-prepared Bi 2 S 3 hierarchitectures displayed superior capacity of Cr(VI) photoreduction to P25 and irregular Bi 2 S 3 nanostructures under visible light irradiation. Effects of morphology, pH value of reaction system, Cr(VI) concentration, and catalyst dosage on the Cr(VI) photoreduction capacity of Bi 2 S 3 hierarchitectures were also discussed. The enhancement of photoreduction capacity is not only attributed to the intrinsic good electron transfer ability of Bi 2 S 3 , but also to synergetic effects of special architectures, wide photoresponse range, high light photoadsorption, high BET surface area and good electron-hole separation performance. The systematic condition experiments and Cr(VI) photoreduction in electroplating and tannery wastewater experiments further demonstrated that the hierarchical Bi 2 S 3 nanospheres can be used in the actual Cr(VI)-containing wastewater treatment.
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MICROCHIMICA ACTA
·
2016
·Vol. 184
·期 1
·195-202
·
IF 4.831
Wang Yanying,Han Miao,Ye Xiaoxue,Wu Kangbing,Wu Tsunghsueh,Li Chunya
The ionic liquid 1-{3-[(2-aminoethyl)amino]propyl}-3-vinylimidazole bromide was synthesized and used to fabricate a molecularly imprinted film for electrochemical sensing of myoglobin (Myo). This film was deposited on a glassy carbon electrode modified with multi-walled carbon nanotubes by using the ionic liquid as the functional monomer, Myo as the template, N,N′-methylenebisacrylamide as the crosslinker, and a redox system containing ammonium persulfate and N,N,N′,N′-tetramethylethylenediamine as the initiator. The sensing performance of the modified electrode was investigated by using the hexacyanoferrate system as an electrochemical redox probe. The results demonstrated that the sensor possesses good selectivity and high sensitivity. The oxidation peak current at the potential of ~0.3 V (vs. SCE) was found linearly related to the myoglobin concentration in the range from 60.0 nM to 6.0 μM, with a 9.7 nM detection limit at an S/N ratio of 3. The sensor was applied to the determination of Myo in spiked serum samples where it showed average recoveries (for n = 5) of 96.5 %.
By using a polymerizable ionic liquid as the functional monomer, a myoglobin imprinted polymer was fabricated on a multi-walled carbon nanotube modified glassy carbon electrode. The sensing performances of the molecularly imprinted sensor towards myoglobin demonstrated good selectivity, sensitivity and accuracy.
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POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Zeqi Zhang,Liang Qiao,Xue Bi,Keshan Zhang,Wenchao Zhang,Rongjie Yang
Vinyl ester resin (VER) are widely used in various applications, including automotive parts, yachts, wind turbine blades, and cooling towers, due to their excellent properties. However, the high flammability of VER limits its application in fields requiring stringent fire resistance. In this work, we used ionic liquid containing phospholipid structures (VIDHP) in combination with lithium-containing polyhedral oligomeric phenyl sesquisiloxanes (Li-POSS) to improve the mechanical and flame retardant properties of VER. The coordination between the VIDHP and Li-POSS increases the thermal stability of VIDHP and improve the solubility of Li-POSS in VER. The experimental results show an increase in initial decomposition temperature of VIDHP4/POSS1/VER compared to VIDHP/VER, while the solubility of Li-POSS in VER is improved. The Cone calorimeter results show that the total heat and smoke release of VIDHP4/POSS1/VER are reduced by 29.37 % and 36.55 % compared with the pure VER. The investigation of the flame retardant mechanism shows that the combined use of VIDHP and Li-POSS exhibits flame-retardant activity in both the gas and condensed phases, effectively enhancing the flame-retardant property of VER.
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ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Zhiyuan Wang,Zhiyong Su,Yuan Xu,Jianguang Qi,Baohui Qi,Xueyang Wei,Xingjian Chen,Yufeng Hu,Zhichang Liu,Xin Guo
With the increasing emphasis on sustainable development, people have realized that energy transformation is the key to solving the global energy and climate crisis. 1,3,5-Trioxane (TOX), as a crucial chemical raw material, is an important substitute for anhydrous formaldehyde, and the production of bulk industrial products through TOX is a significant way to extend the C1 industry chain. However, in the industrial synthesis process of TOX, coexisting water (H2O) and TOX form an azeotrope. This paper proposes for the first time a novel method of using green and environmentally friendly 1,3-dimethylimidazolium dimethyl phosphate ([MMIM][DMP]) ionic liquid as an entrainer to separate TOX and H2O through extractive distillation. Based on the COSMO-RS model, [MMIM][DMP] was screened and understood to be the most promising entrainer. Vapor–liquid equilibrium (VLE) experiments demonstrated that [MMIM][DMP] can obviously break the azeotropic point of the (TOX + H2O) system, the critical concentration for breaking the azeotropic point is about 1 mol/kg. The TOX + H2O + [MMIM][DMP] ternary VLE data were regressed by the NRTL model, e-NRTL model, Wilson model, and UNIQUAC model, and the results showed that the NRTL model achieved the best regression accuracy. In addition, the separation mechanism of [MMIM][DMP] breaking the azeotropic point of the TOX + H2O system was evidenced by the density functional theory and the COSMO-RS model. Finally, by conducting experiments on the extractive distillation pilot device, it was further verified that under the conditions of solvent ratio 2 and reflux ratio 1, TOX could be completely separated from H2O by using [MMIM][DMP] as an entrainer, and the TOX product with a mass fraction greater than 99.5% was obtained. Compared with the traditional use of organic solvents as extractants to separate TOX, this method can avoid the challenges of volatility and toxicity, demonstrating its enormous potential in promoting sustainable development.
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高影响因子
Sustainable Chemistry and Pharmacy
·
2024
·
IF 5.5
Jing Chen,Jin Zhang,Rundong Liang,Mingyue Ma,Yan Cui
The work established a new method combining MILs with ultrasound to effectively extract naphthoquinone pigments from green walnut husk. With the yield of juglone as the index, some parameters were optimized by single factor experiment with UV. Optimal extraction conditions were determined to be as follows: extraction solvent of [C 4 MIM] [FeCl 4 ], ratio of liquid to material of 10 mL/g, extraction temperature of 60 °C and extraction time of 60 min. Based on this method, the extraction yield of green walnut husk pigment was as high as 85.52% (g/g), which was a lot higher than that of heat-reflux extractions with ethanol and NaOH. Subsequently, the extracted pigment was used as a colorant in the hair dyeing combined with eugenol and tea polyphenol as natural accelerating agent and mordant. The process was optimized by orthogonal experiment, and the hair treated with the extracts got by MB-UA-E was the darkest when pH was kept at 5.0, the pigment concentration was 60%, the dyeing temperature was kept at 70 °C, and the dyeing time was 40 min. Compared to two products obtained by reflux extraction, the extracts got by MB-UA-E showcased superior black dyeing capacity, higher tensile strength, less damage to hair scales or α-keratin and greater UV protection property. It caused less damage to structural of hair fiber than commercial oxidative dye despite participation of conditioner in the oxidative dye. Our study could open new possibilities for using recycled walnut waste in the field of hair dyeing with an eco-friendly and efficient method.
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COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2024
·
IF 8.1
Zeqi Zhang,Xue Bi,Wenchao Zhang,Rongjie Yang
In daily life, the application of vinyl ester resin (VER) and its carbon fiber composites is limited by their flame retardancy and mechanical properties. In this work, we synthesized an ionic liquid, VIDHP, from diethyl hydroxymethyl phosphate (DHP) and 1-vinylimidazole (VIM). VIDHP can not only cross-links with VER but also enhances the interaction between the resin and the carbon fiber. The flame retardancy and mechanical properties of VER and its carbon fiber composites were effectively improved by the addition of VIDHP. In particular, the addition of 15 wt% VIDHP increased the flexural strength and flexural modulus of the carbon fiber composites by 29.3 % and 42.4 %, while reducing the total heat release and total smoke release by 15.4 % and 18.4 %. The flame retardant mechanism of VIDHP was also investigated. This approach provides a new idea to improve the flame retardant and mechanical properties of VER and its carbon fiber composites.
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高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Zongkui Qin,Tian Lei,Shanshan Wang,Leilei Liu,Zhijian Tan
Herein, four novel poly(ionic liquid)@poly(N-isopropylacrylaminde) microgels were prepared and doped into polyvinylidene fluoride (PVDF) to fabricate eight temperature-responsive mixed matrix membranes (TRMs) for the efficient separation of natural citrus flavonoids, viz. naringin, neohesperidin, naringenin, and hesperetin. Dynamic light scattering of microgels in water at 20 and 50 ℃ confirmed their temperature-responsive properties. Water flux of TRMs at different temperatures proved their switchable response characteristic between 30 and 35 ℃. The mechanical property, pore size distribution, porosity, and specific surface area of these TRMs were measured. Moreover, the chemical structure, microstructure, hydrophobicity, thermostability, anti-fouling performance, and charge property were also confirmed for them. The M4 membrane exhibited a maximum separation selectivity of 81.66% at 20 ℃. Binding energy of G4 microgel to flavanone glycosides through H-bonding was greater than that of G4/flavanones. These TRMs, as a kind of novel separation materials, have the potential in the separation of various natural products.
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危险品化学品经营许可证（带存储）