COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Jianhua Kang,Sultan Ahmed Khoso,Yuehua Hu,Wei Sun,Zhiyong Gao,Runqing Liu
A selective organic depressant was investigated to promote the separation of scheelite from calcite and fluorite . 1-Hydroxyethylidene-1, 1-diphosphonicacid (HEDP) could efficiently reduce the recoveries of calcite and fluorite to less than 20%, while that of scheelite remained above 85%. The selective interaction mechanism was demonstrated via Zeta potential and X-ray photoelectron spectroscopy (XPS) analyses. The conceivable adsorption models of reagents on mineral surfaces were constructed to explain their adsorption mechanism. HEDP exhibited an excellent ability to selectively depress calcite and fluorite attributed to the intense adsorption on their surfaces, whereas its adsorption on scheelite surface was feeble. The technology feasibility of using HEDP to improve the scheelite flotation performance was verified through laboratory and industrial tests. The roughing grade was dramatically improved from 1.22% to 1.68%, and the product grade was enhanced from 24.66% to 28.26% with a noteworthy improvement of cleaning recovery by 6.93%, which would produce a considerable economic benefit.
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JOURNAL OF MOLECULAR LIQUIDS
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2016
·
IF 2.74
Xiaojie Wang,Xiaopo Wang,Dongbo Wang
Densities and kinematic viscosities of binary mixtures for ethyl caprate with 1-propanol, 1-butanol, and 1-pentanol were measured at temperatures from 283.15 K to 318.15 K and at ambient pressure (0.1 MPa) over the entire composition range. Excess molar volumes and viscosity deviations of the mixtures were derived from the experimental data and correlated using the Redlich–Kister equation. In addition, viscosities were correlated using the McAllister three-body model, whereas densities were fitted to a third-order polynomial as a function of temperature and mole fraction.
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Nanoscale
·
2017
·Vol. 9
·期 42
·16375-16385
·
IF 7.367
Shengju Zhou,Lin Wang,Mengjun Chen,Baoyong Liu,Xiaofeng Sun,Meirong Cai,Hongguang Li
Superstructures from fullerene C60-containing compounds, especially those tethered to rigid functional groups with defined shapes, remain largely unexplored. Being the smallest diamondoid, adamantane (Ad) can be viewed as a promising building block for the construction of well-defined superstructures. Here, we report the syntheses of 1 : 1 (4a) and 2 : 1 (4b) Ad-C60 hybrid molecules, which were then used to construct superstructures in binary solvent mixtures via a modified liquid/liquid interfacial precipitation (LLIP) method using CHCl3 as a good solvent. Typically in the combination of DMSO/CHCl3 with a final concentration (cf) of 1.0 mmol L−1, 4a successively forms spheres, plates, nanoflowers and plicated particles with increasing content of DMSO while 4b forms cuboid blocks and microparticles with hierarchically organized surfaces. Changing from DMSO to other poor solvents including acetone, MeOH and EtOAc leads to variations of the morphology of the superstructures for both 4a and 4b. At the nanometer length scale, 4a and 4b adopt different organizations within the superstructures. While 4a tends to self-organize into lamellae with highly ordered C60 layers, the hexagonal phase is dominant in the superstructures formed by 4b. Wettability tests indicate that films formed by the superstructures of 4a and 4b show anti-wetting properties. Besides the solvent effect, the morphology of the superstructures can be also tuned by concentration. For example, when cf is lowered to 0.5 mmol L−1, a new form of superstructure, i.e., fibers, was detected for 4a. Our results also indicate that besides the solvent-induced aggregate transition, gravity-induced sedimentation and subsequent structure ripening can have a significant influence on the final morphology of the superstructures and the aggregate transition pathways.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Shuxiu Yang,Qingzhu Shu,Bona Fu,Shuhong Liu,Yong Zhang,Hong Zhao
One important approach to address the cost issue of fuel cells is to maximize the utilization of Pt by reducing its loading and enhancing the performance for the oxygen reduction reaction (ORR) as well as durability of catalysts. In this work, a one-step synthesis of highly dispersed low-Pt (1 1 1) electrocatalysts (p-Pt/KBs) supported by Ketjenblack is conducted using interaction between solution and nonthermal plasma (SNP). The results show that the plasma-treated platinum precursor dispersion efficiently avoids particle agglomeration and increases more defects of the support surface, which are conducive to the trapping and anchoring of platinum nanoparticles (Pt NPs). The catalyst (p-Pt/KB-NaOH) with a platinum load of 10.8 wt% is obtained by adding sodium hydroxide to the platinum precursor dispersion solution, showing better ORR performance (E 1/2 = 0.88 V) and stability compared to the commercial platinum on carbon (Pt/C) catalyst (20 wt%, E 1/2 = 0.86 V). This improvement is attributed to the fact that neutralizing chloroplatinic acid slows down the reduction rate of the platinum precursor, effectively controlling the rapid nucleation and slow crystal growth of platinum. As the cathode catalyst for PEMFCs, p-Pt/KB-NaOH exhibits remarkable mass-transfer performance in the high-current density domain (HCD), with maximum power density (P max ) of 1131 mW cm −2 at 2500 mA cm −2 , which is 9.1 % higher than commercial Pt/C. Moreover, the single-cell operates stably for at least 100 h at 1000 mA cm −2 with a negligible decay (1.9 %) of the working voltage, ensuring long-term durability.
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MICROCHIMICA ACTA
·
2013
·Vol. 181
·期 3
·471-477
·
IF 3.434
Xu Zhenning,Yin Huanshun,Tian Zhengbin,Zhou Yunlei,Ai Shiyun
We report on an electrochemical method for the determination of the activity of the enzyme methyltransferase (MTase). The methyl-binding domain-1 protein was applied to recognize symmetrically methylated cytosine in CpG (-C-phosphate-G-) islands of ds-DNA which then specifically bind to anti-His tag antibody. Hyperbranched rolling circle amplification (RCA) was used to improve sensitivity. When the dsDNA was treated with M.Sss I methyltransferase, the sequence 5′-CCGG-3′ was methylated and recognized by the methyl binding protein. In turn, the anti-His tag, biotinylated IgG, streptavidin and biotinylated oligonucleotide were captured successively on the surface of an electrode. Subsequently, the RCA reaction was initiated and streptavidin-labeled alkaline phosphatase immobilized on the surface of the electrode. ALP was able to catalyze the hydrolysis of 1-naphthyl phosphate to form 1-naphthol at pH 9.8. The oxidation peak current of 1-naphthol was used to monitor the methylation process. The response obtained by differential pulse voltammetry was linearly related to the concentration of M. Sss I MTase in the range from 0.1 to 40 unit mL −1 , and the detection limit was 0.03 unit mL −1 (at an SNR of 3). The inhibitory action of paclitaxel on the activity of M.Sss I MTase also was investigated.
An electrochemical immunosensing method is described for the detection of DNA methylation, assaying DNA methyltransferase activity by combining the rolling circle amplification technique.
研究领域:
生物化学
·
分子生物学
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分析化学
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生物技术
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JOURNAL OF CATALYSIS
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2024
·
IF 6.5
Gongcheng Sun,Subing Fan,Junmin Lv,Tiansheng Zhao
A hollow zeolite encapsulated Rh catalyst Rh@H-S-1 with an “eggshell” structure was prepared using the method of organic alkali treatment and recrystallization. Compared with catalysts with directly encapsulated Rh@S-1 and surface impregnated Rh/S-1, this catalyst exhibited both superior activity and a higher TOF value in hydroformylation of 1-hexene due to the high dispersion of Rh and high diffusion. The Rh element did not need to be reduced in the preparation, and it was in situ reduced by the syngas. The content of lower valence Rh δ+ gradually increased with the reaction procedure and played as an active center. The low oxidized state Rh + or Rh δ+ in the form of Rh(CO) 2 are proposed as active sites in hydroformylation, which were generated under the synergistic effect between CO and H 2 . Importantly, the hollow encapsulated catalyst effectively decreased Rh leaching to 0.1 ppm and showed better stability compared with the impregnated Rh/S-1 catalyst.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2021
·
IF 2.694
Yuanyuan Han,Mai Han,Houchun Yan,Qingqing Yin,Qingsong Li
Liquid–liquid equilibrium (LLE) data for the ternary mixture of water + furfuryl alcohol (FAL) + {1-pentanol and n-propyl acetate} was measured in 101.3 kPa at 303.2, 313.2, and 323.2 K. The separation factor (S) and distribution coefficient (D) appraised the utility of extracting FAL from water. The experimental data were accurately correlated by the nonrandom two-liquid (NRTL) and the universal quasi-chemical (UNIQUAC) models with the root-mean-square deviation (RMSD%) values. The values are less than 0.37%. The relevant binary interaction parameters were calculated. The GUI-MATLAB was used to check the consistency of the calculated binary interaction parameters and liquid–liquid equilibrium data. The σ-profiles can analyze the molecular interaction, which further confirms the accuracy of the experimental results. The excellent performance of 1-pentanol and n-propyl acetate in the extraction of FAL from an aqueous solution was shown.
研究领域:
化学工程
·
热力学
·
物理化学
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2020
·
IF 2.369
Lili Zhang,Yingmin Yu,Zhaohui Liao,Xiaosheng Xu,Xin Huang,Bing Jia,Qingsong Li
Liquid–liquid equilibrium data (LLE) of ternary systems {water + 1-butanol + 1-hexanol} and {water + 1-butanol + 1-octanol} were investigated at 303.15, 313.15, and 323.15 K at 101.3 kPa. The distribution coefficient (D) and selectivity factor (S) were calculated from experimental LLE data. Meanwhile, the effect of temperature on the two-phase zone of the two systems was discussed. The nonrandom two liquid and universal quasi-chemical activity coefficient models were used to regress experimental data sets and generate the relevant binary interaction parameters. Both thermodynamic models provided similar good descriptions for the studied systems with root mean square deviations between the calculated and experimental values less than 0.3%.
研究领域:
化学工程
·
物理化学
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Dan Du,Zhirong Qu,Weiwei Zhang,Hong Dong,Chuan Wu
The density, viscosity and speed of sound of trimethoxylsilane derivatives with ethanol, 1-butanol, 1-pentanol and 1-octanol have been measured at 298.15, 303.15, 308.15, 313.15 K, 318.15 and 323.15 K, respectively. The excess molar volume, viscosity deviation, excess Gibbs energy of activation of viscous flow, isobaric thermal expansivity and isentropic compressibility deviation were calculated from these results. The Redlich–Kister equation was used for the correlation. The calculated excess properties have been discussed according to the possible interactions formed between the molecules in the mixture using equimolar attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. In all of the compositions and experimental temperature ranges studied, the excess molar volumes were found to be negative for vinyl trimethoxy silane and phenyl trimethoxy silane with ethanol. This may be attributed to the close accumulation of molecules and easier formation of cross-association structures between the alkoxysilane molecules. However, the excess molar volume of the binary mixture of vinyl trimethoxy silane and phenyl trimethoxy silane with n -butanol, n -pentanol, and n -octanol was positive. Hydrogen bond fracture may play a leading role in this process. The excess molar volumes of the binary system comprised of trifluoropropyl trimethoxy silane with ethanol and 1-octanol were all positive. This may be attributed to the influence of steric hindrance, which makes it difficult for trifluoropropyl trimethoxy silane to form a cross-association structure with alcohol molecules.
研究领域:
物理化学
·
材料科学
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高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2015
·
IF 1.098
Jun Wang,Manman Wang,Xuzhao Yang,Wenyuan Zou,Xiang Chen
The structure of a room temperature asymmetrical dicationic ionic liquid (ADIL), 1-(pyridinium-1-yl) propane-(1-methylpiperidinium) bi[bis(trifluoromethanesulfonyl)imide] ([PyC 3 Pi][NTf 2 ] 2 ), was studied by the X-ray diffraction method. Meanwhile, thermal analysis of [PyC 3 Pi][NTf 2 ] 2 was also studied using non-isothermal thermogravimetric analysis (TGA). The title crystal belongs to the triclinic with space group P ī and unit-cell parameters a = 0.95217 (8) nm, b = 1.05129 (11) nm, c = 1.70523 (14) nm, α = 89.759 (8)°, β = 80.657 (7)°, γ = 68.007 (9)°, and F (000) = 792. Thermal stability and thermal decomposition kinetics of the title compound were also investigated using TGA under the atmosphere of highly pure nitrogen. Heating curves at different rates were correlated with kinetic equations Friedman and ASTM (also called iso-conversion method). The values of average activation E (kJ·mol − 1 ) and pre-exponential constant lg A are 149.58 kJ·mol − 1 and 8.83, respectively, which were obtained by the two methods. The kinetic model function, activation energy and pre-exponential constant of this reaction using the multivariate non-linear-regression method were f ( α ) = (1 − α )(1 + 4.1870 α ), 151.04 kJ·mol − 1 and 8.81, respectively, which were basically consistent with iso-conversion methods.
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APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Guodong Jiang,Meng Wei,Songdong Yuan,Qing Chang
4-chlorophenol could be efficiently photoreductively dechlorinated over anatase TiO 2 nanocrystals with co-exposed {0 0 1} and {1 0 1} facets, which were synthesized and further characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Although fluorine could adsorb on {0 0 1} facets to decrease their surface energy, enabling TiO 2 to expose high energy {0 0 1} facets, the surface bonded fluorine might depress the photoreductive dechlorination efficiency of 4-chlorophenol, attributed to the electron trapping role of surface ≡Ti F groups. Due to the formation of a surface heterojunction between {1 0 1} and {0 0 1} facets in a single TiO 2 nanocrystal, electrons and holes were spontaneously self-separated and selectively migrate to {1 0 1} and {0 0 1} facets, respectively. Electron trapping experiments demonstrated that photogenerated electrons are the responsible for the reductive dechlorinaton of 4-chlorophenol to phenol. To avoid the oxidative degradation of 4-chlorophenol by holes and ensure sufficient electrons to reductively dechlorinate the substrate, moderate scavengers were required in the reaction system and dissolved oxygen, which might deplete electron on TiO 2 , also should be removed. With the optimal scavengers, the conversion efficiency of 4-chlorophenol (4-CP) achieved 97.5% and the selectivity for phenol was 92.5%, which were much higher than that of commercial TiO 2 P25.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Hao-Min Song,Li-Xia Zhao,Shuai-Qi Zhang,Tong Ye,Ying Fu,Fei Ye
Cinnamic acid, isolated from cinnamon bark, is a natural product with excellent bioactivity, and it effectively binds with cyclohexanedione to form novel 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors. According to the active sub-structure combination principle, a series of novel 3-hydroxy-2-cinnamoyl-2-en-1-one derivatives were designed and synthesized. The title compounds were characterized by infrared, 1H NMR, 13C NMR, and HRMS. The in vitro inhibitory activity of AtHPPD verified that compound II-13 showed the most activity with a half-maximal inhibitory concentration (IC50) value of 0.180 μM, which was superior to that of mesotrione (0.206 μM) in vitro. The preliminary herbicidal activity tests demonstrated that some compounds had good herbicidal activity especially compound II-13 at a concentration of 150 g ai/ha. The binding mode of AtHPPD through molecular docking indicated that two oxygens of compounds II-13 formed bidentate interactions with metal ions, and the benzene ring formed π-π accumulation effects with Phe-381 and Phe-424. The results of molecular dynamics simulations showed that compound II-13 exhibited a more stable binding ability with AtHPPD than mesotrione. This study provided insights into the development of natural and efficient herbicides in the future.
研究领域:
化学
·
药理学
·
农业科学
·
分子生物学
·
植物科学
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高影响因子
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