INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Wei Du,Longjing Bai,Yue Gong,Lei Zhang,Jun Xiang,Songbo Wang,Na Tang,Liang Zhu,Qiuxiang Yin
The homogeneous nucleation during fast cooling crystallization and the heterogeneous nucleation during the solution-mediated polymorphic transformation (SMPT) of p-nitrobenzoic acid (PNBA) were investigated to elucidate the connection between the molecular self-assembly and the nucleation process. Process analytical technology (PAT) tools, such as attenuated total reflection-Fourier-transform infrared (ATR-FTIR) spectroscopy were successfully applied to highlight the existence of solution-phase dimers and monomers. The combination of solubility measurements, measured nucleation induction time, polymorphic outcome and transformation, and computational chemistry was used to demonstrate the connection among solvation, molecular self-assembly in solution, and the nucleation pathway of PNBA. The orders of solubility and nucleation rates in different solvents were found to be consistent with those of solute–solvent binding energies. The dimerization of PNBA molecules in hydrogen-bonded dimers and stacked dimers through π–π interactions seem similar in all four solvents investigated in this study, which indicates that the desolvation of PNBA is the key step during the overall nucleation pathway.
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高影响因子
OPTICAL MATERIALS
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2019
·
IF 2.687
Jing Fang,Shujuan Zhuo,Changqing Zhu
In this study, we presented a facile strategy to synthesis Cu-doped carbon dots (Cu-CDs) through one-step hydrothermal approach using CuCl 2 ·2H 2 O and ethanediamine as reaction precursor. Interestingly, the fluorescence of Cu-CDs can be quenched greatly in the presence of p -nitrophenol. Thus, a high selectivity and sensitivity fluorescent sensing platform is constructed for the detection of p -nitrophenol on account of the inner filter effect . Under the optimal condition, the linear detection range is 0.5–50 μM with the detection limit of 0.08 μM (S/N = 3). This method is successfully applied in quantification of p -nitrophenol in lake water samples, which exhibits potential application prospect.
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高影响因子
IONICS
·
2019
·Vol. 25
·期 7
·3189-3196
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IF 2.289
Wang Ping,Zhou Yiyang,Xu Pei,Ding Yunsheng
Dielectric relaxation spectroscopy (DRS) was used to investigate the effect of morphological evolution on conductivity behavior of PLA/PCL blends containing P[MPEGMA-IL]. The morphology of blends changes from sea-island morphology into co-continuous morphology with increasing P[MPEGMA-IL] content. P[MEPGMA-IL] could mainly localize in PCL domains and expand to the interface layer between the PLA and PCL phase because of the low viscosity of PCL phase and the high affinity of MEPGMA groups for both polymer phases. The dielectric results were discussed in terms of α relaxation that corresponds to normal and segmental mode movement, interfacial polarization that corresponds to interfacial aggregation of charge carriers, and ac conductivity that originates from conductive network of mobile charge carriers. Co-continuous morphology and high ions concentration lead to the enhancement of segment movement and ion conductive channel in PCL phase, which correspond to high conductivity and low activation energy of PLA/PCL/8P[MEGMA-IL] blend.
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高影响因子
ACS Applied Energy Materials
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2019
·
IF 0
Di Chen,Rong-Hua Zhang,Qing-Yun Hu,Yi-Fei Guo,Wei Zhan,Shao-Na Chen,Xin-Wen Zhou,Zhong-Xu Dai
One kind of phosphorus (P)-doped nanohollow structure (NHs) CuPdNiP catalyst has been synthesized by a facile, green, and low-cost two-step method. The introduction of P element successfully shortens the interatomic distance between Pd and Ni and thus enhances the ethanol oxidation reaction (EOR) performance in alkaline media compared with homemade and commercial Pd black. The mass activity of CuPdNiP NHs (1191.02 mA mg–1Pd) is almost 5.8 times higher than commercial Pd black catalyst (205.19 mA mg–1Pd). The long-term durability test shows a 7.4% decline of MA, much lower than commercial Pd black (17.1%), demonstrating the excellent EOR stability of CuPdNiP NHs. It is modified surface-atom distribution that promotes the EOR performance, and this kind of synthetic strategy can be applied to design other novel metallic-based catalysts.
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Frontiers in Materials
·
2019
·
IF 2.689
Xie Lijuan,Li Zhong,Sun Linchao,Dong Baoxia,Fatima Qawareer,Wang Zhe,Yao Zhengjun,Haidry Azhar Ali
Titanium dioxide is considered as one of the potential candidates for high-temperature gas sensing applications due to its excellent sensitivity and stability. However, its practical use as a gas sensor under elevated conditions is limited on account of its selectivity and insufficient understanding of response conversion from n- to p-type. To this context, the present work is intended to prepare and understand the p-type response of anatase TiO2 toward H2 gas (20–1,000 ppm) at elevated temperature (500°C). Sol-gel route is adopted to facilely synthesize powders containing pure and chromium (1–10 at.%) doped TiO2 nanoparticles, which are then brushed onto substrates with already patterned inter-digitated platinum electrodes. In this work, even, the undoped TiO2 samples showed p-type gas sensing response, which then decreased with Cr doping. However, in comparison to previously reported work, the sensing characteristics of all sensors is improved. For instance, 5 at.% Cr-TiO2 showed high response (147), fast response and recovery (142/123s) time, and good selectivity to hydrogen against monoxide and methane. Despite better response values, the TiO2 based samples show instability and drift in baseline resistance; such issues were not observed for Cr-doped TiO2 samples (≥3 at.%). The powders were further analyzed by XRD, SEM, TEM, and XPS to understand the basic characteristics, p-type response and stability. Further, a plausible sensing mechanism is discussed on basis of results obtained from aforementioned techniques.
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高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-8
·
IF 5.479
Li Chunmei,Zheng Youkun,Ding Hongwei,Jiang Hui,Wang Xuemei
We report on the synthesis of chromium(III)-doped carbon dots (Cr-CDs) by one-pot hydrothermal pathway using tris(2, 4-pentanedionato) chromium(III) and polyethyleneimine as precursors. The Cr-CDs have a graphene-analogous structure and display blue-green fluorescence with excitation/emission maxima at 350/466 nm, a 20% quantum yield, and excitation-independent emissions. Their cytotoxicity is low. The Cr-CDs were used as a fluorescence probe for p -nitrophenol ( p -NP). The assay has a linear working range that extends from 0.8~150 μM and a 0.27 μM lower detection limit. The assay was applied to the detecting of p -NP in spiked human urine, and conceivably may be extended to a method for the determination of parathion.
Schematic presentation for the synthesis of Cr-CDs (chromium(III)-doped carbon dots) and their application to the fluorometric determination of p -NP ( p -nitrophenol) based on an inner filter effect.
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PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Kui Wu,Yajun Li
The solid-liquid equilibrium data and solution thermodynamics of chemicals are indispensable for the synthesis and purification of crystalline products in industry. The selection of a solvent directly influences the yield and purity of a product. In this work, the solubility of p -toluenesulfonamide ( p -TSA) in 16 pure solvents, methanol, ethanol, n -propanol, isopropanol, n -butanol, isobutanol , n -pentanol, isopentanol, acetone, ethyl acetate , acetonitrile , cyclohexanone , cyclopentanone , methyl acetate , ethyl formate and dichloromethane , was determined by a static gravimetric method at temperatures ranging from 273.15 to 324.75 K under atmospheric pressure. The results indicate that the mole fraction solubility of p -TSA increased with increasing temperature in all 16 solvents. The solubility value in the selected alcohols ranks in the following order: methanol > ethanol > n -propanol > isopropanol > n -butanol > n -pentanol > isopentanol > isobutanol , and the polarity of a solvent seems to be an important factor influencing the solubility of p -TSA in alcohols. In the other eight solvents, the solubility sequence is cyclopentanone > acetone > cyclohexanone > (acetonitrile, methyl acetate) > ethyl acetate > ethyl formate > dichloromethane , which strongly deviates from the order of solvent polarities. Then, the measured solubility data were correlated with four thermodynamic models, i.e., the modified Apelblat equation, λh equation, non-random two-liquid (NRTL) equation and the Wilson equation. Overall, the NRTL model provided the most satisfactory fitting results. Furthermore, the dissolution thermodynamic parameters, Gibbs energy (△ dis G ), molar enthalpy (△ dis H ) and molar entropy (△ dis S ) were calculated according to the Wilson model. The values of △ dis H and △ dis S are positive in all selected solvents, showing that the dissolution process of p -TSA in the selected solvents is endothermic and entropy-driven. The △ dis G values are negative in all selected solvents and decrease with increasing temperature, which demonstrates that dissolution of p -TSA in the selected solvents is favorable and spontaneous.
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高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2019
·
IF 3.218
Jinghua Shang,Minggang Zhao,Huiyan Qu,Hui Li,Rongjie Gao,Shougang Chen
The 3D Ni/NiO/MoO 3 /chitosan foam was fabricated and the interfacial barrier of p-n junction was proposed as a driving factor for electrochemical detection of Cu 2+ . The electrochemical response resulted from the decreased barrier height caused by the absorbed Cu 2+ . The liner range (0–25 μM) and the lower detection limit (5.69 nM) were obtained. The direct electrochemical detection of Cu 2+ in real water sample with excellent stability and recovery was achieved. It affords a new approach to achieve the direct electrochemical detection of metal ions with depressed interference by employing the interfacial effects of p-n junction.
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高影响因子
CARBOHYDRATE POLYMERS
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2019
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IF 6.044
Maruthupandy Muthuchamy,Rajivgandhi Govindan,Kadaikunnan Shine,Veeramani Thangasamy,Naiyf S. Alharbi,Muneeswaran Thillaichidambaram,Jamal M. Khaled,Jun-Li Wen,Khalid F. Alanzi
In this study graphene/chitosan nanoparticles (GR/CS NCs) were developed. The homogenous combination of GR and CS was confirmed by FTIR spectroscopy. The combination of CS with GR sheets reduced the XRD intensity of the GR peak in GR/CS NCs, while TEM images revealed the immobile CS coating of GR sheets. Further, the anti-biofilm activity of GR/CS NCs was tested. The tests showed that the formation of biofilm by Pseudomonas aeruginosa and Klebsiella pneumoniae was inhibited at 40□g/mL GR/CS NCs up to 94 and 92 %, respectively. The intracellular and cell surface damage of the bacteria was observed by CLSM and SEM. Also, GR/CS NCs produced a toxic effect of 90 % on Artemia franciscana at 70□g/mL upon 24 h incubation. The recorded properties of the synthesized GR/CS NCs qualify them as potential agents against multi-drug resistant bacteria.
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PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2019
·
IF 7.015
Huayong Luo,Kelin Wu,Qin Wang,Tian C. Zhang,Hanxing Lu,Hongwei Rong,Qian Fang
We explore the feasibility of utilizing electro-responsive hydrogels as novel forward osmosis (FO) draw agents for desalination. The chemically cross-linked hydrogels were synthesized via free radical copolymerization of common acrylamide (AM) with strong anionic comonomer 2-acrylamido-2-methyl- 1 -propanesulfonic acid (AMPS). The morphology, chemical structure , water-adsorbing capacity, and water state of the hydrogels were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), a swelling test, and differential scanning calorimetry (DSC). The water-swollen hydrogels exhibited electroresponsiveness as shrinking and expanding reversibly with the on-off switching of the electric field in an electrode contact system. The magnitude of hydrogels’ deswelling increased with the increase in the degree of swelling and applied voltages. This dehydration phenomenon was induced by the decrease in hydration power of microcounter ions due to the interaction with the electrodes by water electrolysis. The hydrogels were proved to be capable of generating a reasonable water flux of 2.76 L m −2 h −1 (LMH) from brackish water (2000 ppm NaCl solution) due to their high swelling pressure. In addition, the water flux was affected by the amount of hydrogel particles on the membrane surface. Importantly, the prepared hydrogels could effectively release around 71% of the adsorbed water at an applied voltage of 15 V for 40 min, and were able to maintain their water flux and water recovery performances up to three times regeneration. Results indicate that the electric field is an attractive alternative stimulus for extracting desirable water from the hydrogel draw agent in the FO desalination process.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 16
·14161-14169
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IF 2.324
Xiong Xiaoying,Zhou Zhou,Zhang Zhao,Yang Hui,Zhang Qilong
In this study, rod-like TiO 2 filler was synthesized one-step hydrothermal method and was incorporated into P(VDF-TrFE-CFE) polymer matrix to obtain composites with high dielectric constant. It is found that the morphology and content of TiO 2 fillers play a vital role in tailoring the performance of the as-fabricated composites. The rod-like TiO 2 assembled by numerous nanoparticles maintained its primary shape and homogenously distributed in the matrix, thus achieved sophisticated interface and strong interfacial adhesion with P(VDF-TrFE-CFE) polymer, which together contributed to a dramatic improvement in permittivity of composites. Typically, the dielectric constant of composite with 10 vol% rod-like TiO 2 reaches 160 at 100 Hz, in contrast to 102.5 for the composite with 10 vol% commercial TiO 2 and 47 for pristine P(VDF-TrFE-CFE). This study provides a solution for obtaining high-k dielectric composites with low dielectric loss, which is highly desired for advanced electronic devices.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 6
·4589-4600
·
IF 2.993
Tan Jiabin,He Xiaobo,Yin Fengxiang,Liang Xin,Chen Biaohua,Li Guoru,Yin Huaqiang
In this study, a β-Mo 2 C/N, P-co-doped carbon (NPC) catalyst with a porous structure of β-Mo 2 C nanoparticles loading on NPC matrix was prepared by vacuum-rotary evaporation and followed by a facile pyrolysis process for hydrogen evolution reaction (HER). The porous structure is beneficial for exposing more active sites and the mass transfer during the HER. In addition, the carbon matrixes with the highly doped N and P heteroatoms also provide their positive contributions to its high catalytic activity for HER. Owing to the advantages mentioned above, the optimized catalyst shows a small overpotential of 181 mV for driving a cathodic current density of 10 mA cm −2 , a low Tafel slope of 65.3 mV dec −1 and a high exchange current density of 1.5 × 10 −2 mA cm −2 during HER processes in acid electrolyte. The excellent performance of the β-Mo 2 C/NPC makes it a great potential candidate as the HER electrocatalyst.
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高影响因子
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