FLUID PHASE EQUILIBRIA
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2020
·
IF 2.838
Jinbei Yang,Shucui Han,Qiuju Xu,Meiqiong Yu
The density and viscosity of pure liquid 2, 4-dichlorofluorobenzene and 2, 6-dichlorofluorobenzene were measured in the temperature range of (318.15–348.15) K at the local atmospheric pressure of 99.8 kPa. The saturated vapor pressures of pure 2, 4-dichlorofluorobenzene and 2, 6-dichlorofluorobenzene and the isobaric vapor-liquid equilibria (VLE) data for the 2, 4-dichlorofluorobenzene + 2, 6-dichlorofluorobenzene binary system at atmospheric pressure were determined experimentally by a modified Rose still. The density values were accurately described by DIPPR equation. The viscosity data were well correlated using the Litovitz, Ghatee and VFT, and Andrade equations, and the VFT equation shows the best accuracy. Both Antoine and Riedel equations can well describe the relationship between saturated vapor pressure and temperature, which meet the requirements of engineering design. The Riedel equation is more accurate due to the lower average relative deviation. The VLE data were successfully correlated with NRTL and Wilson activity coefficient models, and the interaction parameters were obtained. The result indicates that there is no azeotrope in the binary mixture. The above thermodynamic properties of pure component and the VLE data presented are crucial for the design and operation of distillation for the isomeric mixture separation of 2, 4-dichlorofluorobenzene + 2, 6-dichlorofluorobenzene.
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JOURNAL OF CHROMATOGRAPHY A
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2021
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IF 4.759
Xuan Zhang,Yunhua Hui,Mei Jiang,Youqiong Cai,Dongmei Huang,Guangxin Yang,Cong Kong
A rapid and simple method for the determination of 6 biogenic amines (BAs) in food was established on HPLC-MS /MS without derivatization. Samples were extracted with 5% perchloric acid and cleaned with n-hexane for lipid removal. The analytes were separated on Waters XBridge® HILIC (150 mm × 2.1 mm, 3.5 µm) and analyzed with multiple-reaction monitoring (MRM) mode after positive electrospray ionization on HPLC-MS/MS. Good linearity with high correlation coefficient was obtained between 10-1000 µg/L for cadaverine (CAD), putrescine (PUT), tyramine (TYR) and 2-phenylethylamine (2-PHE) and between 1-100 µg/L for histamine (HIS) and tryptamine (TRY), with the detection limits of the method ranging from 0.1 mg/kg for HIS and TRY, and 1.0 mg/kg for CAD, PUT, TYR and 2-PHE, which are under the residue limit of Chinese regulation. Spiking experiments demonstrated good recoveries between 70.2-114.6%, with relative standard deviations (RSDs) between 0.44-13.01%. This method was validated for BAs determination in liquor, fermented meat products, vegetable products, soybean products, dairy products, seafood and its derived products. These results promise high feasibility for BAs monitoring in various food with easy-to-operate and fast sample preparation process, stable analysis on HPLC-MS/MS without derivatization.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 24
·48804
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IF 2.188
Yan Feng,Runjun Sun,Chengkun Liu,Meiyu Chen,Qiushi Wang
The electrospun polyamide 6 (PA6) membranes are treated with different methods. The rough surfaces with different protuberances size and the fiber diameter are prepared by wet, dry heat, wet heat, and ethanol treatments under relaxation, and the formation mechanisms are analyzed. A relative stable structure of PA6 membrane is also prepared by ethanol treatment under tension, and its structure is as same as the untreated membrane. The dynamic water contact angles (WCAs) of the treated membranes are measured. The starting WCA of the membrane with wet heat treatment under relaxation is 90.95°, which is larger than those of wet, dry heat, and ethanol treatments under relaxation. The effects of surface morphologies with different treatments on wettability are analyzed. For obtaining hydrophobicity, the membrane with wet heat treatment under relaxation was coated by polyvinylidene fluoride (PVDF). The WCA of the membrane increases to 127.1° after coating. From another point of view, the WCA of the PVDF/treated PA6 membrane is much larger than that of the pure casting PVDF membrane, which means the rough surface of the treated PA6 membrane can improve the hydrophobicity of the PVDF membrane. Furthermore, the membrane is endowed with superhydrophobicity (WCA of 153.5°) after being coated by SiO 2 /PVDF due to the multilevel structured surface roughness. It is a relative low cost and convenient operation method to prepare the superhydrophobic material. The results provide a novel preparation method of the superhydrophobic material and a treatment method of the electrospun PA6 membrane to obtain a stable structure. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48804.
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CARBOHYDRATE POLYMERS
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2019
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IF 6.044
Hao Qian,Xiaofei Shen,Hailong Huang,Yan Zhang,Mingtao Zhang,Huiqing Wang,Zhongkai Wang
Cellulose graft copolymers are an effective way to endow new properties to cellulose substrate, as well the rigidity, regularity, and helicity of the cellulose backbone could induce the self-assembly of supramolecular structures. In this work, right-handed helical poly(phenyl isocyanide)s (PPI n ) were grafted selectively onto C-6-cellulose. Alkyne-terminated PPI n was synthesized by living polymerization of right-handed phenyl isocyanide monomer using an alkyne-terminated palladium(II) complex as an initiator/catalyst, and were grafted onto the C-6 of the cellulose backbone (Cell-6-g-PPI n ) at various chain lengths using copper-catalyzed alkyne-azide cycloaddition (CuAAC) “click” chemistry. We confirmed the successful grafting by liquid 1 H NMR and 13 C NMR, as well as solid 13 C NMR, FTIR, and GPC. After grafting onto cellulose, the right-handed chirality of PPI n was significantly increased by 111.2%. Additionally, the Cell-6-g-PPI n exhibited better chiral recognition of L-Phe-DNSP than PPI n alone. Therefore, the helical cellulose backbone has enhanced effect on preferred helix of PPI n .
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2019
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IF 2.931
Jing Zou,Yixin Huang,Lirong Zhu,Zheng Cui,Baoling Yuan
A spectrophotometric method using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as the indicator was proposed for measuring persulfates, i.e., peroxymonosulfate (PMS) and peroxydisulfate (PDS). This method was based on the direct oxidation of the colorless ABTS by PMS/PDS to generate the green-colored ABTS + at neutral pH and room temperature . The generated ABTS + had four different characteristic absorption peaks at 820 nm, 732 nm, 650 nm and 415 nm. The absorption values at these wavelengths increased with the increase of PMS/PDS concentration, and there were well linear relationships (R 2 > 0.998) between the corresponding absorption values and the concentrations of PMS/PDS in the range of 3–500 μM. Monitoring the change of PMS/PDS concentration by the proposed ABTS method was in good agreement with that monitored by the common spectrophotometric method using potassium iodide as the indicator. The green-colored waste solutions produced after PMS/PDS analysis with the ABTS method showed no bactericidal effect towards Escherichia coli . The proposed multi-wavelength spectrophotometric method using ABTS as the indicator could be employed as a candidate method for the accurate and convenient measurement of PMS/PDS in water.
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JOURNAL OF MICROENCAPSULATION
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2019
·
IF 2.04
Ran Li,Rui Bao,Qiu-Xuan Yang,Qi-Long Wang,Michael Adu-Frimpong,Qiu-Yu Wei,Toreniyazov Elmurat,Hao Ji,Jiang-Nan Yu,Xi-Ming Xu
Aims: The aim was to improve the absorption and bioavailability of [6]-shogaol with β-cyclodextrin (β-CD) prior to in vitro and in vivo evaluation.Methods: [6]-Shogaol/β-CDs inclusion complexes (6-S-β-CDs) were developed using saturated aqueous solution method and characterised with appropriate techniques. The absorption and bioavailability potential of [6]-shogaol was evaluated via in vivo pharmacokinetics and in situ intestinal perfusion.Results: The results of characterisation showed that 6-S-β-CDs (drug loading, 7.15%) were successfully formulated. In vitro release study indicated significantly improved [6]-shogaol release. Pharmacokinetic parameters such as Cmax, AUC0–36 h, and oral relative bioavailability (about 685.36%) were substantially enhanced. The in situ intestinal perfusion study revealed that [6]-shogaol was markedly absorbed via passive diffusion in the intestinal segments, and duodenum followed by ileum and jejunum.Conclusions: Cyclodextrin inclusion technology could enhance the intestinal absorption and oral bioavailability of hydrophobic drugs like [6]-shogaol.
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高影响因子
TALANTA
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2019
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IF 4.916
Shuang Tan,Rui Han,Shilian Wu,Huan Liang,Yuting Zhao,Hui Zhao,Can-Peng Li
Competitive host-guest recognition has been utilized to determine small molecules using macrocyclic supramolecular host, while less studies focused on the specific recognition and sensing of protein. In the present work, we are the first time to report a label-free fluorescent assay for insulin determination based on the supramolecular recognition between cationic pillar[6]arene (CP6) and insulin. The approach is based on fluorescence resonance energy transfer (FRET) through competitive recognition between CP6 functionalized reduced graphene oxide (CP6@rGO) and probe/insulin molecules. Probe molecule (RhB) has strong fluorescent signal, and its fluorescent is quenched by rGO based on FRET. When target protein molecule (insulin) is added to CP6@rGO, the probe is displaced by insulin and a host-guest complex CP6@rGO/insulin is formed, resulting in a “turn-on” fluorescence signal. The fluorescence intensity of complex increased linearly with the increase of insulin concentration ranging 0.01–0.50 and 1.0–16.0 μM, respectively with a detection limit of 3 nM. The sensor was successfully utilized to determine insulin in artificial serum. The molecular docking result showed that the N-terminal Phe of insulin's B chain was included in the CP6 cavity through electrostatic interaction and formed a stable host-guest complex.
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NEW JOURNAL OF CHEMISTRY
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2015
·Vol. 39
·期 12
·9714-9721
·
IF 3.086
Yufeng Zhou,Naizhong Song,Haijiao Zheng,Xueju Lv,Bin Hu,Qiong Jia
In the present study, a poly(butyl methacrylate-co-ethylene dimethacrylate) (poly(BMA–EDMA)) monolithic column modified with allyloxy-cucurbit[6]uril (ACB[6]) was prepared with an in situ polymerization process. A polymer monolith microextraction method was developed with the modified monolithic column for the preconcentration of estrogen combined with high performance liquid chromatography. The various experimental parameters affecting the extraction capacity were investigated and optimized with an orthogonal experiment design, L16(45). Under the optimum conditions, we obtained acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. Hydrophobic interactions, π–π stacking, and hydrogen bonding interactions contributed to the extraction efficiency of the ACB[6]@poly(BMA–EDMA) monolithic column. The present method was employed to determine estrogens in cosmetic samples and the accuracy was assessed through recovery experiments. The obtained recovery values were in the range of 80.1–109.4% with relative standard deviations less than 9.9%.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2014
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IF 0.872
Zhijian HE,Xiaomin WANG,Tian YAO,Hang SONG,Shun YAO
Four novel benzothiazolium ionic liquids with PF − 6 ([C 1 Bth][PF 6 ], [C 4 Bth][PF 6 ], [C 5 Bth][PF 6 ] and [C 6 Bth][PF 6 ]) were synthesized, and the rang of their melting points were determined between 358.35 K–424.05 K. The relationship of their melting points and the length of the straight alkyl chain on cation reflected ‘S’ type tendency. Then, the solubilities of the four ionic liquids in six lower alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) were measured in the temperature rang of 253.15–383.15 K at atmospheric pressure with static analytical method, respectively. It was found that [C 6 Bth][PF 6 ] in all investigated ionic liquids had the largest solubility in six alcohols and the solubility of [C 4 Bth][PF 6 ] in methanol was very sensitive for temperature in 313.15–333.15 K, which was so-called “temperature-sensitivity”. This feature is of great significance to their application of catalyzing reaction or extraction process, and makes the recovery and reuse of ionic liquids (ILs) become easier. Moreover, the experimental solubility data were correlated with the modified Apelblat equation and λ h equation, respectively. It was found that the result of correlation using two divided temperature ranges was better than that of using the whole temperature range.
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NEW JOURNAL OF CHEMISTRY
·
2015
·Vol. 39
·期 10
·7971-7978
·
IF 3.086
Huan Liu,Kai Tao,Peipei Zhang,Wei Xu,Shenghu Zhou
Ordered tungsten and aluminum co-doped mesoporous KIT-6 catalysts (W-Al-KIT-6) with different Si/Al molar ratios were successfully synthesized by a one-pot synthesis method. The obtained W-Al-KIT-6 catalysts were tested for catalytic conversion of 1-butene and ethene to propene via isomerization of 1-butene to 2-butene and subsequent cross metathesis of 2-butene and ethene. Various characterization techniques, such as ICP-OES, XRD, BET, TEM, Raman, XPS and NH3-TPD, were used to characterize the catalysts. The introduction of Al did not change the mesoporous structure of KIT-6 when the nominal Si/Al was 10, 20 or 30. Moreover, the sample demonstrated a larger amount of acidic sites. The W-Al-KIT-6 catalysts with suitable Si/Al ratios illustrated a superior catalytic performance to W-KIT-6 catalyst. The origin of catalytic performance enhancement over W-Al-KIT-6 catalysts is preliminarily discussed and ascribed to the highly disperse W species and a large amount of acidic sites. The acidic sites were formed by the introduction of a suitable amount of Al in the W-KIT-6 framework, which accelerated the isomerization of 1-butene to 2-butene and promoted the cross metathesis of 2-butene and ethene to propene.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2016
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IF 2.76
Lixia Zhang,Hongli Li,Guang Chu,Lan Luo,Jing Jin,Bing Zhao,Yuan Tian
The silver nanowires (AgNWs) were prepared through the method of polyol. The prepared AgNWs were characterized by TEM image, UV–vis spectroscopy and X-ray diffraction (XRD). AgNWs were assembled onto silicon wafer through entropy-driven self-assembly method. The 521 cm −1 band of silicon was used as internal standard band. The SERS performance of AgNWs-Si substrate was characterized by using R6G as the probe molecule, and the SERS substrate is employed to detect 6-MP. The linear concentration range of 6-MP is 0.05–3.8 μmolL −1 and the corresponding correlation coefficient is 0.994. The method is satisfactory for detecting 6-MP in two kinds of commercial tablets.
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MATERIALS RESEARCH BULLETIN
·
2016
·
IF 2.435
Shuqiang Jiao,Jingjing Tuo,Hongliang Xie,Zihang Cai,Shuai Wang,Jun Zhu
Prussian blue analogues (PBAs) have recently attracted extensive interests as a new class of cathode materials for rechargeable batteries. Copper hexacyanoferrate, a typical Prussian blue analogue with the chemical formula Cu 3 [Fe(CN) 6 ] 2 , has been synthesized by solution precipitation method and investigated as a cathode material for sodium-ion batteries. The galvanostatic cycling tests show a specific capacity of 44 mA h g −1 at a current density of 20 mA g −1 , and the capacity retention can be 57.1% after 50 cycles. The material can also deliver a specific capacity of 37 mA h g −1 and 25 mA h g −1 at a rate of 50 mA g −1 and 100 mA g −1 , respectively. Furthermore, the material exhibits a high reduction peak at 3.32 V vs. Na + /Na, which brings more power to sodium-ion batteries. The data indicate the as-prepared material is capable of realizing the single electron redox capacity due to the reduction of Fe 3+ /Fe 2+ . All of the findings suggest a possible use of Cu 3 [Fe(CN) 6 ] 2 nanoparticles as environmental friendly and cost-effective cathode material, which also open new perspectives to develop cathode materials for sodium-ion batteries.
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