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  • Uncertainty-conscious methodology for process performance assessment in biopharmaceutical drug product manufacturing
    AlChE J. (IF 2.836) Pub Date : 2017-11-20
    Gioele Casola, Hirokazu Sugiyama, Christian Siegmund, Markus Mattern

    This work presents an uncertainty-conscious methodology for the assessment of process performance—for example, run time—in the manufacturing of biopharmaceutical drug products. The methodology is presented as an activity model using the type 0 integrated definition (IDEF0) functional modeling method, which systematically interconnects information, tools, and activities. In executing the methodology, a hybrid stochastic–deterministic model that can reflect operational uncertainty in the assessment result is developed using Monte Carlo simulation. This model is used in a stochastic global sensitivity analysis to identify tasks that had large impacts on process performance under the existing operational uncertainty. Other factors are considered, such as the feasibility of process modification based on Good Manufacturing Practice, and tasks to be improved is identified as the overall output. In a case study on cleaning and sterilization processes, suggestions were produced that could reduce the mean total run time of the processes by up to 40%. © 2017 American Institute of Chemical Engineers AIChE J, 2017

    更新日期:2017-11-20
  • A branch and bound algorithm to solve large-scale multistage stochastic programs with endogenous uncertainty
    AlChE J. (IF 2.836) Pub Date : 2017-11-20
    Brianna Christian, Selen Cremaschi

    The growth in computation complexity of multistage stochastic programs (MSSPs) with problem size often prevents its application to real-world size problems. We present two variants of branch-and-bound algorithm, which reduce the resource requirements for the generation and solution of large-scale MSSPs with endogenous uncertainty. Both variants use Knapsack-problem based Decomposition Algorithm (Christian and Cremaschi, Comput Chem Eng. 2015;74:34–47) to generate feasible solutions and primal bounds. First variant (PH-KDA) uses a progressive hedging dual-bounding approach; the second (OSS-KDA) solves the MSSP removing all nonanticipativity constraints. Both variants were used to solve several instances of the pharmaceutical clinical trial planning problem. The first iteration of both algorithms provides a feasible solution, and a primal bound and a dual bound for the problem. Although the dual-bounds of OSS-KDA were generally weaker than PH-KDA, they are generated considerably faster. For the seven-product case the OSS-KDA generated a solution with a gap of 9.92% in 115 CPU seconds. © 2017 American Institute of Chemical Engineers AIChE J, 2017

    更新日期:2017-11-20
  • DEM study on the discharge characteristics of lognormal particle size distributions from a conical hopper
    AlChE J. (IF 2.836) Pub Date : 2017-11-20
    Ya Zhao, Shiliang Yang, Liangqi Zhang, Jia Wei Chew

    This study employs the discrete element method (DEM) to investigate the impact of the widths of lognormal particle size distributions (PSDs) with the same mean particle diameter on hopper discharge behaviors, namely, discharge rate, particle velocities, and size-segregation. Results reveal that (i) the hopper discharge rate decreases as PSD width increases; (ii) the mean discharge rates are constant with time, but the fluctuations increase as the PSD width increases; (iii) the overall size-segregation increases with PSD width; (iv) the overall mean particle diameters of the narrower PSDs do not exceed the initial mean of 5 mm, whereas that of wider ones do; (v) the relationship between PSD width and particle velocities is non-monotonic with no consistent trends; and (vi) no direct correlation exists between particle velocity and size-segregation. The results here provide valuable insights on the behavior of the prevalent polydisperse mixtures in hoppers. © 2017 American Institute of Chemical Engineers AIChE J, 2017

    更新日期:2017-11-20
  • Reducing Diastereomorphous Bis(phosphane oxide) Atropisomers to One Atropisomerically Pure Diphosphane: A New Ligand and a Novel Ligand-Preparation Design
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Frank Sartorius, Marc Trebing, Charlotte Brückner, Reinhard Brückner
    更新日期:2017-11-20
  • Fatty Acid Chain Shortening by a Fungal Peroxygenase
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Andrés Olmedo, José C. del Río, Jan Kiebist, René Ullrich, Martin Hofrichter, Katrin Scheibner, Angel T. Martínez, Ana Gutiérrez
    更新日期:2017-11-20
  • Reversible Oxidative Se−Se Coupling of Phosphine Selenides by Ph3Sb(OTf)2
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Maximilian J. Poller, Neil Burford, Konstantin Karaghiosoff
    更新日期:2017-11-20
  • Braking of a Light-Driven Molecular Rotary Motor by Chemical Stimuli
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Thomas van Leeuwen, Wojciech Danowski, Stefano F. Pizzolato, Peter Štacko, Sander J. Wezenberg, Ben L. Feringa
    更新日期:2017-11-20
  • Novel CYP6D1 and voltage gated sodium channel alleles of the house fly (Musca domestica) and their roles in pyrethroid resistance
    Pest Manag. Sci. (IF 3.253) Pub Date : 2017-11-20
    Jing Pan, Chan Yang, Yan Liu, Qi Gao, Mei Li, Xinghui Qiu

    This work demonstrates the effect of genetic mutations in CYP6D1 and Vssc on the susceptibility of house flies to pyrethroids, and verifies that 15bp insert-containing CYP6D1 alleles have a single origin. These findings offer insights into the evolution of insecticide resistance and have implication for house fly control.

    更新日期:2017-11-20
  • Elevated difenacoum metabolism involved in the difenacoum-resistant phenotype observed in Berkshire rats homozygous for the L120Q mutation in Vkorc1 gene
    Pest Manag. Sci. (IF 3.253) Pub Date : 2017-11-20
    Maylis Boitet, Abdessalem Hammed, Nolan Chatron, Jean Valéry Debaux, Etienne Benoit, Virginie Lattard

    This study demonstrated that an elevated CYP450-oxidative metabolism leading to an accelerated difenacoum detoxification is involved in the Berkshire phenotype.

    更新日期:2017-11-20
  • α,α-Alkylation-Halogenation and Dihalogenation of Sulfoxonium Ylides. A Direct Preparation of Geminal Difunctionalized Ketones
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Rafael D. C. Gallo, Anees Ahmad, Gustavo Metzker, Antonio C. B. Burtoloso
    更新日期:2017-11-20
  • Priming of cowpea volatile emissions with defense inducers enhances the plant's attractiveness to parasitoids when attacked by caterpillars
    Pest Manag. Sci. (IF 3.253) Pub Date : 2017-11-20
    Islam S. Sobhy, Toby J. A. Bruce, Ted C. J. Turlings

    Our findings confirm that treating cowpea plants with inducers can enhance their attractiveness to biological control agents.

    更新日期:2017-11-20
  • Advantages of diapause in Trichogramma dendrolimi mass production via eggs of the Chinese silkworm, Antheraea pernyi
    Pest Manag. Sci. (IF 3.253) Pub Date : 2017-11-20
    Jun-Jie Zhang, Xue Zhang, Lian-Sheng Zang, Wen-Mei Du, Yang-Yang Hou, Chang-Chun Ruan, Nicolas Desneux

    In a three-year augmentative field release from 2014 to 2016, diapaused Trichogramma showed effective parasitism on eggs of the Asian corn borer, Ostrinia furnacalis. These results indicated that diapaused T. dendrolimi can be an efficient and alternative method for mass rearing of T. dendrolimi for long-term cold storage.

    更新日期:2017-11-20
  • A Facile and Green Method for the Synthesis of SFE Borosilicate Zeolite and Its Heteroatom-Substituted Analogues with Promising Catalytic Performances
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Yi Luo, Zhendong Wang, Junliang Sun, Yingying Wang, Shaoqing Jin, Bin Zhang, Hongmin Sun, Weimin Yang
    更新日期:2017-11-20
  • Rational Design of Branched Au–Fe3O4 Janus Nanoparticles for Simultaneous Trimodal Imaging and Photothermal Therapy of Cancer Cells
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Xiangjun Chen, Guilan Li, Qinghe Han, Xiliang Li, Lu Li, Tingting Wang, Chungang Wang
    更新日期:2017-11-20
  • Acenequinocumulenes: Lateral and Vertical π-Extended Analogues of Tetracyanoquinodimethane (TCNQ)
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Marco Gruber, Kevin Padberg, Jie Min, Andreas R. Waterloo, Frank Hampel, Harald Maid, Tayebeh Ameri, Christoph J. Brabec, Rik R. Tykwinski
    更新日期:2017-11-20
  • Enantioselective Synthesis of 6,6-Disubstituted Pentafulvenes Containing a Chiral Pendant Hydroxy Group
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Ryan Nouch, Melchior Cini, Marc Magre, Mohammed Abid, Montserrat Diéguez, Oscar Pàmies, Simon Woodward, William Lewis
    更新日期:2017-11-20
  • Near-Infrared-Absorbing Organometallic Diruthenium Complex Intermediates: Evidence for Bridging Anthrasemiquinone Formation and against Mixed Valency
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Thangavel Sathiya Kamatchi, Sudipta Mondal, Thomas Scherer, Martina Bubrin, Karuppannan Natarajan, Wolfgang Kaim
    更新日期:2017-11-20
  • Streptavidin as a Scaffold for Light-Induced Long-Lived Charge Separation
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Sascha G. Keller, Andrea Pannwitz, Hendrik Mallin, Oliver S. Wenger, Thomas R. Ward
    更新日期:2017-11-20
  • Experimental Evaluation of (L)Au Electron-Donor Ability in Cationic Gold Carbene Complexes
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Robert G. Carden, Nathan Lam, Ross A. Widenhoefer
    更新日期:2017-11-20
  • Halide Abstraction Competes with Oxidative Addition in the Reactions of Aryl Halides with [Ni(PMenPh(3−n))4]
    Chem. Eur. J. (IF 5.317) Pub Date : 2017-11-20
    Ignacio Funes-Ardoiz, David J. Nelson, Feliu Maseras
    更新日期:2017-11-20
  • 更新日期:2017-11-20
  • Cover Image, Volume 39, Issue 2
    J. Comput. Chem. (IF 3.229) Pub Date : 2017-11-20
    更新日期:2017-11-20
  • ENZYMATIC HYDROLYSIS AT HIGH DRY MATTER CONTENT: THE INFLUENCE OF THE SUBSTRATES’ PHYSICAL PROPERTIES AND OF LOADING STRATEGIES ON MIXING AND ENERGETIC CONSUMPTION
    Bioresource Technol. (IF 5.651) Pub Date : 2017-11-20
    Federico Battista, Mélanie Gomez Almendros, Romain Rousset, Serge Boivineau, Pierre-Antoine Bouillon

    The present work investigates the impact of the physical properties and loading strategies of wheat straw and miscanthus on enzymatic hydrolysis at high DM concentration. Three parameters have been chosen to evaluate the enzymatic hydrolysis performance: (i) the mixing time, (ii) the energetic mixing consumption and (iii) the glucose concentration. It was demonstrated that the hydrolysis of miscanthus is easy to perform and has low viscosity. On the contrary, the higher porosity grade of wheat straw than miscanthus (73% against 52%) contributed to have a very high viscosity at 20% w/w DM. The development of a fed-batch strategy allowed the reduction of viscosity inducing the energetic consumption lowering from 30 kJ to 10 kJ. It has been also proven that the miscanthus addition in wheat straw achieved to decrease mixing energy consumption at 5-8 kJ, when it represented more than 30% of the total mass of the reaction medium.

    更新日期:2017-11-20
  • Evaluation of Engineered Hydrochar from KMnO4 Treated Bamboo Residues: Physicochemical Properties, Hygroscopic Dynamics, and Morphology
    Bioresource Technol. (IF 5.651) Pub Date : 2017-11-20
    Wei Yan, Huanhuan Zhang, Kuichuan Sheng, Ahmed M. Mustafa, Youfang Yu

    In this study, a novel approach was developed to prepare engineered hydrochar from KMnO4 treated bamboo residues through hydrothermal carbonization. The hydrochar yields were within a specified range of 61.8 - 67.8% at 180 °C and 39.8 - 45.0% at 260 °C, respectively. The higher temperature led to the higher C content, lower H/C and O/C ratio, whereas the ash content increased with increasing KMnO4 concentration, causing the increase of solid yield as well as the decrease of C content. Pseudo-second kinetic model was optimal to describe bamboo hydrochar’s hygroscopic dynamic, and the engineered hydrochar produced at 260 °C and 1.0 wt% concentration obtained the better hydrophobicity of 0.82%. SEM-EDS and XRD analysis confirmed the existence of manganese carbonate on the surface of engineered hydrochar, from which we inferred the chemical complexation between KMnO4 and hydrochar.

    更新日期:2017-11-20
  • Enhanced effects of maghemite nanoparticles on the flocculent sludge wasted from a high-rate anammox reactor: performance, microbial community and sludge characteristics
    Bioresource Technol. (IF 5.651) Pub Date : 2017-11-20
    Zheng-Zhe Zhang, Ya-Fei Cheng, Yu-Hui Bai, Lian-Zeng-Ji Xu, Jia-Jia Xu, Zhi-Jian Shi, Qian-Qian Zhang, Ren-Cun Jin

    Magnetic nanoparticles (NPs) have been widely applied in environmental remediation, biomass immobilization and wastewater treatment, but their potential impact on anaerobic ammonium oxidation (anammox) biomass remains unknown. In this study, the short-term and long-term impacts of maghemite NPs (MHNPs) on the flocculent sludge wasted from a high-rate anammox reactor were investigated. Batch assays showed that the presence of MHNPs up to 200 mg L-1 did not affect anammox activity, reactive oxygen species production, or cell membrane integrity. Moreover, long-term addition of 1-200 mg L-1 MHNPs had no adverse effects on reactor performance. Notably, the specific anammox activity, the abundance of hydrazine synthase structural genes and the content of extracellular polymeric substance were increased with elevated MHNP concentrations. Meanwhile, the community structure was shifted to higher abundance of Candidatus Kuenenia indicated by high-throughput sequencing. Therefore, MHNPs could be applied to enhance anammox flocculent sludge due to their favorable biocompatibility.

    更新日期:2017-11-20
  • Hydrothermal liquefaction of microalgae over Transition metal supported TiO2 catalyst
    Bioresource Technol. (IF 5.651) Pub Date : 2017-11-20
    Wenjia Wang, Youtong Xu, Xiaoxiao Wang, Bokun Zhang, Wenying Tian, Jinglai Zhang

    Hydrothermal liquefaction (HTL) of microalgae Nannochloropsis (NAS) over various transition metal M/ TiO2 (M = Fe, Co, Ni, Mo, and Mn) was investigated. Ni/TiO2 was the most effective catalyst to improve the yield and quality of biocrude and the liquefaction conversion. Ni/TiO2 was characterized by XRD, XRF, and XPS. The research of Effect of reaction temperature on HTL of NAS over Ni/TiO2 suggested that 300 °C led to a maximum biocrude yield of 48.23% and the highest liquefaction conversion of 89.28%. Adding Ni/TiO2 catalyst reduced the viscosity and provided more light-fraction in biocrude while brought a slight increase in total acid number (TAN). Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that adding Ni/TiO2 considerably changed the composition of biocrude and the possible pathways were discussed. Reproduction test showed the Ni/TiO2 has an excellent reproduction ability in HTL of NAS.

    更新日期:2017-11-20
  • Lead-Free Hybrid Perovskite Absorbers for Viable Application: Can We Eat the Cake and Have It too?
    Adv. Sci. (IF 9.034) Pub Date : 2017-11-20
    Lusheng Liang, Peng Gao
    更新日期:2017-11-20
  • Modified Back Contact Interface of CZTSe Thin Film Solar Cells: Elimination of Double Layer Distribution in Absorber Layer
    Adv. Sci. (IF 9.034) Pub Date : 2017-11-20
    Zhaojing Zhang, Liyong Yao, Yi Zhang, Jianping Ao, Jinlian Bi, Shoushuai Gao, Qing Gao, Ming-Jer Jeng, Guozhong Sun, Zhiqiang Zhou, Qing He, Yun Sun
    更新日期:2017-11-20
  • Hydrothermal Cation Exchange Enabled Gradual Evolution of Au@ZnS–AgAuS Yolk–Shell Nanocrystals and Their Visible Light Photocatalytic Applications
    Adv. Sci. (IF 9.034) Pub Date : 2017-11-20
    Jingwen Feng, Jia Liu, Xiaoyan Cheng, Jiajia Liu, Meng Xu, Jiatao Zhang
    更新日期:2017-11-20
  • Pollen and bee bread as new health-oriented products: A review
    Trends Food Sci. Tech. (IF 5.191) Pub Date : 2017-11-20
    Marek Kieliszek, Kamil Piwowarek, Anna M. Kot, Stanisław Błażejak, Anna Chlebowska-Śmigiel, Iwona Wolska

    Background An interest in substances of natural origin has been a subject that is increasing constantly-both those known for many years and recently discovered are of great interest to the researchers. This interest also applies to bee products because of their extensive nutritional and therapeutic properties; these products are known and used for several thousand years, but only recently, they became the subject of sparse documented scientific research. With the passing of time, it is difficult to determine what will be the wishes and requirements of the future consumers, what should be introduced to new technologies to ensure the demand for new products. Scope and approach Recently, there has been an increasing demand for natural products, particularly the bee products. Bee bread and pollen, due to their nutritional and medicinal properties, are used for apitherapeutic purposes. These include about 200 different substances, such as free amino acids and vitamins. Special attention should be attributed to unsaturated fatty acids such as linoleic, linolenic, and arachidonic, which are found in pollen and bee bread. Key finding and conclusion The fashion for a healthy lifestyle leads to a situation where a number of people start taking care of their health. They search for the highest quality products, preferably with health benefits, rich in vitamins, valuable bioelements, and nutrients. Therefore, bee bread that is rich in beneficial ingredients has proved to fulfill these expectations. It constitutes a wholesome, biologically active nutrient, which can be used in the food industry.

    更新日期:2017-11-20
  • Antioxidants: Reviewing the chemistry, food applications, legislation and role as preservatives
    Trends Food Sci. Tech. (IF 5.191) Pub Date : 2017-11-17
    Márcio Carocho, Patricia Morales, Isabel C.F.R. Ferreira

    Background Food antioxidants play a critical role in the food industry, and have become one of the most widespread methods of conserving food. Their cheapness and ease of use have made them a part of virtually all foodstuffs. Although different, all groups of food antioxidants have a same common objective, to conserve food for the longest possible time without altering it, conferring taste or color. Consumer trends have shifted the industry to find natural antioxidants for conservation, and although synthetic additives have been the mainstream, their natural counterparts have been gaining interest. Scope and approach This review focuses of the different antioxidant groups, describing their properties, function and applicability, as well as indexing the relevant legislation in order to be a guide for academia and industry. Key findings and conclusions The wide number of antioxidant additives allowed by the different countries if of synthetic origin, and consist of pure molecules. Although consumers are leaning toward natural additives, this offer is still quite limited despite the permission of rosemary extract within the European Union. There is still much work to be done in order to completely demystify the importance and safety of antioxidants as well as to harmonize legislation worldwide.

    更新日期:2017-11-20
  • Black phosphorene and PEDOT:PSS-modified electrode for electrochemistry of hemoglobin
    Electrochem. Commun. (IF 4.396) Pub Date : 2017-11-20
    Xiaoyan Li, Xueliang Niu, Wenshu Zhao, Wei Chen, Chunxiao Yin, Yongling Men, Guangjiu Li, Wei Sun

    A black phosphorene (BP) and poly(3,4-ethylenedioxythiophene) -poly(styrenesulfonate) (PEDOT:PSS) composite was prepared with the aim of immobilizing hemoglobin (Hb) directly on the electrode. The incorporation of BP into PEDOT:PSS resulted in a stable film. The Hb immobilized on the electrode exhibited direct electron transfer, showing a pair of well-defined redox peaks, indicating that BP accelerated the direct electrochemistry of Hb. This modified electrode exhibited excellent electrocatalytic performance for the reduction of various substrates and was used for detection in real samples with satisfactory results. This demonstrates the potential applications of BP in electrochemical biosensing.

    更新日期:2017-11-20
  • A novel electrochemical chiral interface based on sandwich-structured molecularly imprinted SiO2/AuNPs/SiO2 for enantioselective recognition of cysteine isomers
    Electrochem. Commun. (IF 4.396) Pub Date : 2017-11-20
    Jie Zhang, Wensheng Tan, Yongxin Tao, Linhong Deng, Yong Qin, Yong Kong

    SiO2 nanospheres were synthesized by the sol–gel method using tetraethoxysilane (TEOS) as the precursor, which was then modified with 3-aminopropyltriethoxysilane (APTES) for the grafting of single bond NH2 to the SiO2 surface. Au nanoparticles (AuNPs) were anchored to the single bond NH2 grafted SiO2, and then l-cysteine (L-Cys) templates were introduced to the SiO2/AuNPs through forming Au single bond S bond. Another layer of SiO2 was then coated on the L-Cys doped SiO2/AuNPs as the coating layer, and then the templates were removed by calcination to form a sandwich-structured molecularly imprinted SiO2/AuNPs/SiO2. Finally, the molecularly imprinted chiral interface was applied for electrochemical enantioselective recognition of Cys isomers, and discernible differences in the current signals could be observed on the differential pulse voltammograms (ID-cys/IL-cys, 2.36).

    更新日期:2017-11-20
  • Effective sulfur-doping in carbon by high-temperature molten salt bath and its electrocatalysis for oxygen reduction reaction
    Electrochem. Commun. (IF 4.396) Pub Date : 2017-11-17
    Li Zhang, Yi Wang, Kai Wan, Jin-hua Piao, Zhen-xing Liang

    A facile high-temperature molten salt bath method was developed to effectively dope sulfur into carbon. Molten potassium sulfide acts as a high-concentration sulfur source and provides an immersion bath, thus favoring sulfur doping. Resultant sulfur-doped carbon shows an exceptionally high sulfur content of 1.50 at.%, manifesting its favorable effect on catalysing the oxygen reduction reaction.

    更新日期:2017-11-20
  • The electrochemistry of iron oxide thin films nanostructured by high ion flux plasma exposure
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Rochan Sinha, İrem Tanyeli, Reinoud Lavrijsen, M.C.M. van de Sanden, Anja Bieberle-Hütter

    Photo-electrochemical (PEC) water splitting of hematite photoanodes suffers from low performance and efficiency. One way to increase the performance is to increase the electrochemically active surface area available for the oxygen evolution reaction. In this study, we use high ion flux, low energy helium plasma exposure to nanostructure sputtered iron thin films. Subsequent annealing in air at 645 °C leads to the formation of PEC active hematite (α-Fe2O3) phase in these films. The surface area, as derived from electrochemical impedance spectroscopy (EIS), was seen to increase 10–40 times with plasma exposure. The photocurrent density increased by 2–5 times for the plasma exposed films as compared to the unexposed films. However, the less nanostructured film showed a higher photocurrent density. These findings were explained by detailed chemical and structural characterization in combination with electrochemical characterization and attributed to the presence of secondary elements in the film as well as to the presence of secondary iron oxide phases apart from hematite. This work demonstrates the complex effect of plasma exposure on both film morphology and chemical composition of PEC thin films and provides further understanding on how this technique can be used for nanostructuring of other functional films.

    更新日期:2017-11-20
  • The effect of polyethyleneimine as an electrolyte additive on zinc electrodeposition mechanism in aqueous zinc-ion batteries
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Amir Bani Hashemi, Ghoncheh Kasiri, Fabio La Mantia

    The efficiency of zinc electrodeposition is of fundamental importance for improving long-term performance of aqueous zinc-ion batteries. In order to improve the efficiency of electrodeposition, as well as morphology and reactivity of the deposit, it is possible to use organic additives in the electrolyte. Here, the effect of branched polyethyleneimine (BPEI) as an electrolyte's additive on morphology and kinetic of zinc electrodeposition in 0.5 M of ZnSO4 solution is investigated. The presence of BPEI changes the morphology of the electrodeposited layer from laminated hexagonal large crystals to compact layer without preferential growth morphology. Moreover, we observed that BPEI adsorption on the surface of the substrate suppresses the kinetic of zinc electrodeposition and decreases the grain growth rate, thus favoring the nucleation over the growth. As a result, BPEI ensures a homogeneous distribution of the current densities and can guarantee uniformity of the deposited layer.

    更新日期:2017-11-20
  • A novel electric-field-accelerated ion-sieve membrane system coupling potential-oscillation for alkali metal ions separation
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Xiao Du, Xuli Ma, Pengle Zhang, Junlan Zheng, Zhongde Wang, Fengfeng Gao, Xiaogang Hao, Shibin Liu, Guoqing Guan

    A novel electric-field-accelerated ion-sieve membrane (EISM) system with potential-oscillation was set up for the selective separation of the alkali metal ions. The ion-sieve membrane was fabricated by coating a polypyrrole/polystyrenesulfonate composite on the stainless steel wire mesh (PPy/PSS/SSWM). In the EISM system, an external electric filed was applied by introducing a constant cell voltage on the two sides of the ion-sieve membrane to accelerate the directed transport of target ions through the membrane. Meanwhile, an extra pulse potential was applied on the PPy/PSS/SSWM membrane to adjust the ion binding ability of the PPy/PSS composite toward cations. As such, an enhanced “ion sieving effect” of the EISM system was achieved through the synergistic function of the constant cell voltage and potential oscillation, which resulted in the rapid transport of target cation across the membrane in a “leap-frogging” way. It is found that when an extra pulse potential of ±1.0 V (pulse width of 60 s) was applied on the EISM, the permeation flux of K+ ions was increased by 7.42-fold with a constant cell voltage of 5 V. The permselectivities of the PPy/PSS/SSWM membrane for K+/Li+ and K+/Cs+ reached 3.29 and 3.45 respectively based on the optimized amplitude (±1.0 V) and frequency (pulse width of 60 s) of pulse potential.

    更新日期:2017-11-20
  • Engineering reduced graphene oxides with enhanced electrochemical properties through multiple-step reductions
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Min Wei, Liang Qiao, Hanguang Zhang, Stavros Karakalos, Kuo Ma, Zheng Fu, Mark T. Swihart, Gang Wu

    Currently, the most common approach to preparing graphene is based on oxidation of graphite to graphene oxide (GO), followed by the reduction of GO to reduced graphene oxide (rGO). Currently, most reduction methods only focus on one-step reduction by either thermal annealing or chemical reduction. This is no conclusive understanding which reduction method is superior to the other. Here, using the same GO precursors, we systematically studied various reduction methods to achieve optimal electrochemical properties. We found that, to improve electrochemical properties of rGO, multiple step reduction of GO was more effective when compared to individual methods including thermal annealing, microwave treatment, hydrazine reduction, and borohydride reduction. To evaluate electrochemical performance, rGOs were studied by using cyclic voltammetry to evaluate their electrochemical accessible surface areas and double layer capacitance. Their steady-state oxygen reduction reaction (ORR) activities were compared in both acidic and alkaline electrolytes to study the potential capability to be part of the ORR electrodes. Among these combinations, two-step borohydride and hydrazine reduction (rGO-NaBH4-N2H4) with optimal sequence and conditions is able to completely recover the conjugated carbon structures with minimum defect, thus showing the best electrochemical properties. Importantly, extensive physical characterization including XRD, Raman Spectroscopy, SEM, TEM, BET, and XPS are employed to compare the resulting rGOs in terms of their carbon structures, porosity, surface areas, defect content, and morphologies. These key structural and electrochemical properties of rGOs were found largely dependent on the permutation of reduction methods, in turn, affecting electrochemical properties. The correlation of reduction methods, structures, and properties is established to provide knowledge on engineering rGO through tuning reduction conditions for optimal electrochemical applications.

    更新日期:2017-11-20
  • Porous boron-doped diamond electrode for detection of dopamine and pyridoxine in human serum
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Yanran Li, Hongji Li, Mingji Li, Cuiping Li, Dazhi Sun, Baohe Yang

    A porous boron-doped diamond (PBDD)/Ta sensing electrode was prepared for the fast, sensitive, stable, and discriminative detection of dopamine (DA) and pyridoxine (vitamin B6) in human serum. All the exposed surfaces of the diamond grains of the BDD layer were etched into a porous form, with pore sizes of less than 500 nm and an average depth of about 200 nm. The electrochemical performance characteristics of the PBDD layer and the reaction mechanisms enabling the detection of DA and vitamin B6 were studied. Large numbers of oxygen-containing groups on the PBDD surface, as well as the activity difference of the different planes, enabled us to successfully distinguish between DA and B6 by using the PBDD/Ta electrode. The low background current of PBDD, the large active area of the porous surface, and the high electron transfer properties led to the PBDD electrode having a high sensitivity. Therefore, this sensor can be used to stably detect DA and B6 in serum. Aberrant levels of DA and vitamin B6 in body fluids are key risk indicators for some diseases; thus, monitoring the levels of both and other species in serum is of great significance to clinical diagnoses.

    更新日期:2017-11-20
  • Transition between kinetic and diffusion control during the initial stages of electrochemical growth using numerical modelling†
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Mesfin Haile Mamme, Johan Deconinck, Jon Ustarroz

    Understanding properly electrochemical nucleation and growth phenomena is crucial for a wide range of highly active research and technological fields. In this paper, we use a Finite Element Method to solve a Time Dependent Multi-ion Transport and Reaction Model (FEM-TD-MITReM) to report on the growth of an isolated nucleus. This approach takes into account the transport driven by diffusion and migration of all species in the electrolyte together with the electrochemical reactions at the electrode boundary. The numerical results show that, a nucleus which is smaller than a critical size, even after the application of a sufficiently large overpotential, always starts to grow under kinetic control. In later stages, a transition from kinetic to mixed and to diffusion control takes place. The corresponding transition times between growth regimes have been identified and are found to be inversely proportional to the concentration of active species and to decrease exponentially with overpotential and linearly with the initial nucleus size. Both effects are more pronounced in the transition from kinetic to mixed control. Interestingly, under the conditions used for the current simulations, typical from experimental nucleation and growth studies, a few seconds are needed to achieve diffusion control. This implies that, although experiments under similar conditions are normally described by growth under diffusion control, such theory is only valid for sufficiently large active surface. As a consequence, kinetic and mixed control regimes cannot be neglected for a proper interpretation of electrochemical nucleation and growth phenomena. These findings provide a significant benchmark for correctly describing, modelling and interpreting the early stages of electrochemical growth without making assumptions on the diffusional or kinetic limitations.

    更新日期:2017-11-20
  • An electrochemical study of carbon steel CO2 corrosion in the presence of monoethylene glycol: The effects of pH and hydrodynamic conditions
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Thunyaluk Pojtanabuntoeng, Mobin Salasi

    50 and 80 wt.% monoethylene glycol (MEG)/water mixtures at pH 4 and 6 were tested under different hydrodynamic conditions to investigate the MEG effects on CO2 corrosion of carbon steel. At pH 4, the presence of MEG resulted in a lower and less flow-dependent corrosion current density (icorr i corr ) than those of aqueous solutions. Since MEG changed the physical properties of the solution, it evidently led to a hindered transport of H+ ions to the steel surface and the decreased corrosion kinetics. At pH 6, icorr i corr was slightly increased with shear stress in water-only and 50 wt.% MEG solutions, while it was decreased at 80 wt.% MEG concentration. It was found that at pH 6, MEG predominantly inhibited corrosion by anodic adsorption on the active sites and blocking the ionic transport.

    更新日期:2017-11-20
  • Fabrication of anode-supported microtubular solid oxide fuel cells by sequential dip-coating and reduced sintering steps
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-20
    Nader Hedayat, Dhruba Panthi, Yanhai Du

    The expensive and time consuming fabrication of microtubular solid oxide fuel cells (MT-SOFCs) is one of the main barriers for their commercialization. In this study, a sequential dip-coating coupled with co-firing process was developed to fabricate anode-supported MT-SOFCs using carbon rods as sacrificial template. Both anode and electrolyte layers underwent co-firing at 1400 °C rather than conventional pre-sintering and co-sintering steps. The whole cell structure was fabricated through sequential dip-coating and drying cycles that are flexible to various tube sizes and fast in turnaround time. The fabricated MT-SOFCs were comprised of Ni–yttria-stabilized zirconia (3YSZ) anode support, scandia-stabilized zirconia (ScSZ) electrolyte, Ni-ScSZ anode functional layer, strontium-doped lanthanum manganite (LSM)–ScSZ cathode functional layer, and LSM cathode current collector layer, respectively. The electrochemical performance of the fuel cell was measured at temperatures between 650 and 800 °C. The MT-SOFC delivered stable performance for more than 50 h operation at 700 °C. The fabricated fuel cell also exhibited excellent thermal cycling stability. The results demonstrated that the sequential dip-coating coupled with co-firing is a simple, flexible and cost-effective fabrication process to produce reliable and robust MT-SOFCs.

    更新日期:2017-11-20
  • Preparation and characterization of cross-linked polyphosphazene-crown ether membranes for alkaline fuel cells
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-17
    Yuenan Chen, Ziming Li, Nanjun Chen, Yajun Zhang, Fanghui Wang, Hong Zhu

    A polymer with excellent mechanical properties and chemical properties was selected as the skeleton, and a crown ether instead of the traditional quaternary ammonium and quaternary phosphonium groups was introduced into the polymer. Three crosslinked crown ether membranes (PDB155P-HAH40, 50, and 60) with different crown ether contents were prepared and their structures and properties were characterized. The ionic conductivity of PDB155P-HAH 60 is 78.6 mS/cm at 90 °C. The degradation rates of ionic conductivity were only 2.5% and 0.99% after the membrane was soaked in 4 mol/L NaOH solution for 10 days and in 2 mol/L NaOH solution for 1000 h, respectively. The water uptake and swelling ratio of the membrane are relatively low, and the thermal stability and mechanical properties meet the requirements of the application. These membranes have great potential in the application.

    更新日期:2017-11-20
  • Electrooxidation of glucose by binder-free bimetallic Pd1Ptx/graphene aerogel/nickel foam composite electrodes with low metal loading in basic medium
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-16
    Chi-Him A. Tsang, K.N. Hui, K.S. Hui

    Many 2D graphene-based catalysts for electrooxidation of glucose involved the use of binders and toxic reducing agents in the preparation of the electrodes, which potentially causes the masking of original activity of the electrocatalysts. In this study, a green method was developed to prepare binder-free 3D graphene aerogel/nickel foam electrodes in which bimetallic Pd-Pt NP alloy with different at% ratios were loaded on 3D graphene aerogel. The influence of Pd/Pt ratio (at%: 1:2.9, 1:1.31, 1:1.03), glucose concentration (30 mM, 75 mM, 300 mM, 500 mM) and NaOH concentration (0.1 M, 1 M) on electrooxidation of glucose were investigated. The catalytic activity of the electrodes was enhanced with increasing the Pd/Pt ratio from 1:2.9 to 1:1.03, and changing the NaOH/glucose concentration from 75 mM glucose/0.1 M NaOH to 300 mM glucose/1 M NaOH. The Pd1Pt1.03/GA/NF electrode achieved a high current density of 388.59 A g−1 under the 300 mM glucose/1 M NaOH condition. The stability of the electrodes was also evaluated over 1000 cycles. This study demonstrated that the Pd1Pt1.03/GA/NF electrode could be used as an anodic electrode in glucose-based fuel cells.

    更新日期:2017-11-20
  • The kinetics of transpassive dissolution chemistry of stainless steels in nitric acid: The impact of Si
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-16
    Barbara Laurent, Nathalie Gruet, Benoit Gwinner, Frederic Miserque, Karine Rousseau, Kevin Ogle

    In the present work, atomic emission spectroelectrochemistry was used to monitor the elemental dissolution of two stainless steels during transpassive polarization. A 304LN stainless steel (X2 CrNiN 18-10) was compared with a 3.5 wt% Si rich stainless steel (X1 CrNiSi 18-15-4) so as to elucidate the effect of Si on the dissolution mechanism. The enrichment in Si shifted the cathodic reaction to lower potentials explaining that in hot and concentrated nitric acid containing oxidizing species, 304LN SS corrodes more rapidly due to the transpassive break of passivity, while the 3.5 wt% Si SS remains passive. However, when polarized into the transpassive domain, preferential grain boundary corrosion was observed for the 304LN but not for the 3.5 wt% Si SS, despite having similar current densities. Congruent alloy dissolution was observed in the transpassive domain with the stoichiometry of Fe(III), Cr(VI) and Ni(II) yielding a faradaic yield of 100% at early times. For longer times, with the 304LN, the faradaic yield drop to 70% indicative of intergranular dissolution in which the cations released in the intergranular space were not detected by the ICP-AES. Transmission electron microscopy coupled with energy dispersive spectroscopy showed that the interface of the 3.5 wt% Si SS enriches in Cr during a polarization in the transpassive domain of the steel. No similar enrichment was detected for the 304LN.

    更新日期:2017-11-20
  • Role of crystal lattice templating and galvanic coupling in enhanced reversible capacity of Ni(OH)2/Co(OH)2 core/shell battery cathode
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-16
    Elahe Moazzen, Elena V. Timofeeva, Carlo U. Segre

    A series of Ni(OH)2/Co(OH)2 core/shell nanoplatelets with varying shell thickness (0.5–4.1 nm) are systematically investigated with a combination of scanning electron microscopy (SEM) with energy dispersive x-ray analysis (EDX), x-ray diffraction (XRD), in situ and ex situ x-ray absorption fine structure spectroscopy (XAFS), and electrochemical tests. Structure-properties correlations reveal that electrochemical behavior and reversibility of Co(OH)2 redox conversion depends non-linearly on the average shell thickness, with the best performance (99.6% of theoretical capacity of the composite material, 10% improvement over the performance of pristine Ni(OH)2 nanoparticles) is achieved at shell thickness of 1.9 ± 0.3 nm. Two fundamental phenomena are suggested to be responsible for the superior performance: templated shell deposition and galvanic coupling of core and shell materials. Homogeneous deposition of the shell is confirmed with XRD, SEM and EDX, while lattice templating effect was suggested from XAFS results showing that Co-M and Co-O distances are close to those of the Ni(OH)2 lattice in thin shells and shift gradually towards values of bulk Co(OH)2 as the shell thickness increases. From a combination of electrochemical and structural characterization of these composite nanomaterials, including in situ XAFS, galvanic coupling between the shell and core is proposed as a material activation mechanism. Which explains the limited reversibility of the Co(II)/Co(III) oxidation in some cases. Proposed performance enhancement mechanisms are applicable for design of other core/shell electrode materials.

    更新日期:2017-11-20
  • Effects of various carboxymethyl celluloses on the electrochemical characteristics of zinc anode from an alkaline electrolyte
    Electrochim. Acta (IF 4.798) Pub Date : 2017-11-15
    Chao Yang, Zhijian Zhang, Zhongliang Tian, Yanqing Lai, Kai Zhang, Jie Li

    The effects of molecular weight and solubility of carboxymethyl cellulose (CMC) on the electrochemical characteristics of zinc plate electrodes and Zn-Ni batteries were investigated with and without ZnO in 6 M KOH solution, respectively. The result of electrochemical impedance spectroscopy (EIS) indicated that as an important additive in zinc paste electrodes, CMCs with M.W.s of 700,000, 250,000, and 90,000 can all suppress the corrosion of zinc. The zinc deposition experiment revealed that the CMCs, especially the soluble M.W. 700,000 CMC, can suppress zinc electrodeposition kinetics and decreases the porosity of zinc deposits. Zn-Ni battery performance tests indicate that a suitable concentration of soluble CMC will decrease charge and discharge polarization and increase discharge capacity. These results indicated that various M.W.s and the solubility of CMC in 6 M KOH showed complex electrochemical effects on zinc electrodes in alkaline solution, and their addition to a zinc paste electrode needs careful consideration.

    更新日期:2017-11-20
  • Facile fabrication of nanostructured cerium-manganese binary oxide for enhanced arsenite removal from water
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Jing Chen, Jianyan Wang, Gaosheng Zhang, Qiuyue Wu, Dongtian Wang

    Arsenite [As(III)] is more toxic and more difficult to remove from water than arsenate [As(V)]. For enhanced As(III) removal from water, a new nanostructured Ce-Mn binary oxide with a Ce/Mn molar ratio of 3:1 was fabricated via a facile one-step oxidation-coprecipitation method at ambient temperature. The synthetic Ce-Mn binary oxide is amorphous with a high surface area of 157 m2/g. Cerium (Ce) and manganese (Mn) in this oxide exist mainly in the oxidation state of Ce(IV) and Mn(IV), respectively. It can effectively oxidize As(III) to As(V) and efficently adsorb the formed As(V). Moreover, this sorbent exhibits an obviously synergistic effect. The maximal sorption capacity of As(III) is 97.7 mg/g, which is competitive with most of reported sorbents. The As(III) uptake is rapid and slightly affected by tested solution pH, ionic strength, dissolved organic matters and coexisting anions except for phosphate, indicating the high selectivity toward arsenic. The arsenic-loaded Ce-Mn binary oxide could be readily regenerated and repeatedly used. Both Mn and Ce oxides in sorbent are responsible for As(III) oxidation, and the Ce oxide is dominant for adsorbing formed As(V) during As(III) removal. The oxide could be used as an attractive sorbent for As(III) removal from contaminated water, because of its facile and low-cost synthesis process, good As(III) sorption performance, and reusability.

    更新日期:2017-11-20
  • Dimension Induced Intrinsic Physio-electrical Effects of Nanostructured TiO2on Its Antibacterial Properties
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    LiLin Zhang, Hongwei Bai, Lei Liu, Darren Delai Sun

    TiO2 is one of the wonder materials that possess extraordinary engineering versatility in terms of nanostructures, shapes and morphology. TiO2 nanomaterials have shown superior antibacterial capability, it is however still unclear about the intrinsic dimensional effects on antibacterial mechanisms. This study reported a fundamental antibacterial mechanism about the intrinsic antibacterial capabilities of the engineered nanostructured TiO2 materials (ENMs) – from three aspects 1) the structures of such nanoparticles, rods, tubes, fibres and spheres; 2) sizes/diameters/length of the ENMs; 3) combined effect due to dimensions and structures. Experimental results revealed that, the 1 D nanotubular TiO2, being the smallest individual ENMs possessed the highest toxicity towards E. Coli; further studies showed that 3 D dendritic nanostructure incorporated with 1 D ultrathin TiO2 nanorods had the highest antibacterial efficiency. Comparative studies have suggested that, the well-engineered 3 D TiO2 nanomaterials (microspheres) with enhanced surface properties such as evenly grown 1 D sub-structures were more aggressive than the cluster aggregated 1D nanomaterials. In-depth research concluded that with well-controlled nanorods density and length, the integrated 3 D ENMs exhibited most efficient antibacterial activities. Such results could benefit the future antibacterial applications and the agent fabrications

    更新日期:2017-11-20
  • Non-thermal plasma treatment for the elimination of odorous compounds from exhaust air from cooking processes
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Frank Holzer, Frank-Dieter Kopinke, Ulf Roland

    Non-thermal plasma technique can be a method to improve indoor air quality. In particular in cuisines, odorous emissions can be removed by non-thermal plasmas. In this study 2-methylthiophene, 2-methylpyrazine, 2-acetylthiazole, nonanal and trans-2-nonenal were used as target compounds in concentrations in the low ppmv range. These odorous compounds are emitted during cooking and frying processes. The oxidation of these target compounds as multi-component mixture in a non-thermal gas-phase plasma was studied in dry mixtures of argon and oxygen and in humid air. Complete oxidation of the odorous compounds to COX was achieved in both atmospheres. The energy efficiency was higher in the dry mixture of argon and oxygen, whereas the selectivity of the oxidation towards carbon dioxide was significantly higher in humid air. The main products of plasma treatment were identified as CO, CO2 and polymeric deposits. Some minor organic intermediates in the pptv range were also identified. Although odor carriers could be completely degraded and the concentrations of potentially harmful organic byproducts were several orders of magnitude below critical values, high ozone and CO emissions during plasma operation are crucial for indoor application of non-thermal plasma as stand-alone technique. The combination with a catalytic step, either as in-plasma or post-plasma catalysis, might be a promising approach to tackle this problem.

    更新日期:2017-11-20
  • Facile Synthesis of Hierarchical Porous Metal-Organic Frameworks with Enhanced Catalytic Activity
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Chongxiong Duan, Feier Li, Shaojuan Luo, Jing Xiao, Libo Li, Hongxia Xi

    The development of a general method for the facile synthesis of hierarchical porous metal-organic frameworks (H-MOFs) with tunable porosities is important because of their widespread applications. Herein, through the ingenious use of different neutral organic amines as templates, we report the development of a green and versatile method to synthesize three H-MOFs (Cu-BTC, ZIF-8, and ZIF-90) with tunable morphologies and porosities. The selected neutral amine template molecules deprotonated organic ligands and facilitated the formation of H-MOFs while guiding the formation of meso- and macropores. These high quality as-synthesized H-MOFs possessed micro-, meso-, and macropore hierarchical structures and high thermal stability after the amine templates were removed by simple washing and drying. The as-prepared Cu-BTC H-MOFs exhibited more than 2 times higher activity than conventional microporous Cu-BTC in catalyzing Henry reaction. Our facile strategy establishes a green and general route to synthesize a large variety of H-MOFs for various applications, particularly when large molecules or biomolecules are involved.

    更新日期:2017-11-20
  • Enhancement of adsorption capacity of clay through spray drying and surface modification process for wastewater treatment
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Sunday Joseph Olusegun, Luiz Fernando de Sousa Lima, Nelcy Della Santina Mohallem

    Nowadays, removal of contaminants like dye from wastewater has become an uncompromising task. In view of this, enhancing the performance of adsorbents so as to facilitate the adsorption technique and reduce the overall cost of the purification process is of great interest to industrial sector. In this study, the adsorption capacity of clay was improved by spray drying a dispersed clay solution and also through its surface modification. Fourier transform infrared spectroscopy (FTIR) confirmed that the surface modification was successful; X-ray diffraction (XRD) analysis showed that surface modification did not affect the crystal structure of the clay, and BET specific surface area results attest that spray dried clay has the highest surface area of 102 m2/g. The adsorption tests were carried out using methylene blue and results showed that the adsorption capacity was influenced by solution pH, with maximum adsorption at pH 10 and 120 minutes contact time. Adsorption kinetics data were well fitted to pseudo-second order kinetics model. Langmuir and Freundlich adsorption isotherm models were used to investigate the mechanism of adsorption. Freundlich model is more applicable for this process. Spray dried clay performed better than the modified and raw clay with adsorption capacity of 168 mg/g (at 333 K). The calculated thermodynamics parameters revealed that the adsorption process is spontaneous at all the studied temperatures (303-333 K) for spray dried clay.

    更新日期:2017-11-20
  • Efficient degradation of p-arsanilic acid with arsenic adsorption by magnetic CuO-Fe3O4 nanoparticles under visible light irradiation
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Tianyi Sun, Zhiwei Zhao, Zhijie Liang, Jie Liu, Wenxin Shi, Fuyi Cui

    A bifunctional CuO-Fe3O4 material was synthesized and employed for the photocatalytic degradation of p-arsanilic acid (p-ASA) under visible light irradiation and simultaneous removal of the released inorganic arsenic by adsorption from solution. The effects of major factors, including solution pH, bicarbonate ion, halide ion and humic acid, on the p-ASA degradation were investigated. Under various water quality conditions, an excellent removal of p-ASA could always be achieved by the CuO-Fe3O4 photocatalytic process and p-ASA could be completely converted to As(V) within 36 min. Simultaneously, the released As(V) could be adsorbed onto the surface of CuO-Fe3O4 nanoparticles with high efficiency above 95% at initial pH range from 4 to 7. The presence of humic acid significantly weakened the degradation of p-ASA by scavenging •OH, and slightly inhibited the As(V) removal. On the basis of the UV-vis, FTIR, XPS analysis and the major degradation products detected, the mechanism of the p-ASA photocatalytic degradation and the released As(V) adsorption by CuO-Fe3O4 nanoparticles was given, and the degradation pathway of p-ASA during the photocatalytic process was also taken into consideration. Combined with the photocatalytic property and the high adsorption capacity of As(V), the synthesized magnetic CuO-Fe3O4 nanoparticles have significant potential applications for controlling the risk of p-ASA in wastewater.

    更新日期:2017-11-20
  • Activation of persulfate (PS) and peroxymonosulfate (PMS) and application for the degradation of emerging contaminants
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Jianlong Wang, Shizong Wang

    Sulfate radical-based advanced oxidation processes (AOPs) have been received increasing attention in recent years due to their high capability and adaptability for the degradation of emerging contaminants. Persulfate (PS, S2O82−) and peroxymonosulfate (PMS, HSO5−) can be activated by thermal, alkaline, ultraviolet light, activated carbon, transition metal (such as Fe0, Fe2+, Cu2+, Co2+, Ag+), ultrasound and hydrogen peroxide to form sulfate radical (SO4•-), which is strong oxidant and capable of effectively degrading emerging pollutants. Sulfate radical-based AOPs have a series of advantages in comparison with •OH-based methods, for example: higher oxidation potential, higher selectivity and efficiency to oxidize pollutants containing unsaturated bonds or aromatic ring, wider pH range. Therefore, sulfate radicals are capable of removing the emerging contaminants more efficiently. In this review paper, various methods for the activation of PS and PMS were introduced, including, thermal, alkaline, radiation, transition metal ions and metal oxide, carbonaceous-based materials activation and so on; and their possible activation mechanisms were discussed. In addition, the application of activated PS and PMS for the degradation of emerging contaminants and the influencing factors were summarized. Finally, the concluding remarks and perspectives are made for future study on the activation of PS and PMS. This review can provide an overview for the activation and application of PS and PMS for the degradation of emerging contaminants, as well as for the deep understanding of the activation mechanisms of PS and PMS by various methods.

    更新日期:2017-11-20
  • Immobilization of two polyelectrolytes leading to a novel hydrogel for high-performance Hg2+ removal to ppb and sub-ppb levels
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Mohammad A.J. Mazumder, Mouheddin T. Alhaffar, Shaikh A. Ali

    The cyclotetrapolymerization of four diallylamine salt monomers, containing chelating motifs of aminocarboxylate, aminophosphonate, aminosulfonate and primary amine at the terminal of an alkyl chain (CH2)12, has led to the synthesis of a tetrapolymer in excellent yield. A copolymer of methacrylate having acetyl acetate pendant has also been synthesized. The two polymers in aqueous solution is found to form gel because of covalent crosslinking via formation of imine bond by condensation of -NH2 groups of the tetrapolymer with the acetoacetate groups of the polymethacrylate copolymer. This is the first example of a cyclopolymer immobilized by covalent crosslinking with a polymethacrylate. The hydrogel, embedded with chelating motifs of aminoalkyl- carboxylate, phosphonate and sulfonate as well as imine motifs, demonstrated remarkable efficacies for the removal of Hg(II) ions at ppb levels. A 50 mg-dose of the hydrogel immersed in aqueous medium (20 mL) could reduce the concentration of Hg(II) from 200 and 500 ppb to 0.20 and 0.17 ppb, respectively, within 30 min. The hydrogel has also been shown to be remarkably effective in the removal of several toxic and priority metal pollutants from the matrix of an industrial wastewater.

    更新日期:2017-11-20
  • Multifunctional superamphiphobic SiO2 coating for crude oil transportation
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Yang Wu, Meiyun Zhao, Zhiguang Guo

    Superamphiphobic materials are helping with urgent issues due to increasing industrial oil transportation, as well as common oil pollution, which has triggered large interest owing to their high application value and practicability. However, they are difficult to be fabricated because of the peculiarly shaped surface structures and the substrate-dependent property, and hence, their practical applications has been immensely limited. Herein, we prepare a hierarchical superamphiphobic FOTS-SiO2 powder via a reduction reaction and self-assembly functionalization. Owing to the substrate-independent character and excellent super-repellency of the powder, it can be applied to various substrates to fabricate superamphiphobic coatings. The prepared coatings have a wide range of liquids repellency to water, oils, and even to low-surface-tension liquids like 60 wt.% ethanol-water solution (25.48 mN·m−1) and n-decane (23.8 mN·m−1). What’s more, the coatings also own great water/oil-proofing ability, excellent chemical stability, antifouling and self-cleaning property. Apart from these general performances, we find that the coating has terrific anti-crude-oil-adhesion property, which endows it a new application——crude oil transportation with high efficiency (2.9±0.09 mL/s). All of these advantages will endow the superamphiphobic FOTS-SiO2 particles with broad application prospects, including foodservice industry, petroleum exploitation, crude oil transportation industry, and so on.

    更新日期:2017-11-20
  • Methane diffusion in shales with multiple pore sizes at supercritical conditions
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Mingjun Chen, Yili Kang, Tingshan Zhang, Lijun You, Xiangchen Li, Zhangxin Chen, Keliu Wu, Bin Yang

    Methane diffusion is a very important gas-transport mechanism in shales. Meanwhile, one of the biggest differences between shale gas reservoirs and conventional gas reservoirs is a multiscale pore structure in the former. Two kinds of methane diffusion experiments are conducted in this work to measure methane diffusion coefficients in shale cores at supercritical conditions. Experimental results show that (1) a free molecular diffusion coefficient is averaged to be 1.214×10-10 m2/s at reservoir conditions from the isobaric diffusion experiments; (2) however, the Knudsen diffusion, surface diffusion and configurational diffusion coefficients in the pressure decay experiments are more significant for shale gas development. It is presented that Knudsen diffusion and surface diffusion appear simultaneously as gas transports in matrix nanopores, the mean diffusion coefficients of which are 4.99×10-14 m2/s for pores of a diameter smaller than 4 nm and 9.03×10-9 m2/s for pores of a diameter bigger than 4 nm. The mean configurational diffusion coefficient for dissolved gas is calculated as 2.06×10-22 m2/s. In addition, the four types of diffusion coefficients mentioned above are also theoretically calculated through their corresponding models to compare with the experimental results. Due to the measured methane diffusion coefficients corresponding to a wide range of pore sizes, a relationship between gas diffusion and pore size is obtained by the combination of theoretical and experimental results, and this can guide to further analyze the comprehensive diffusion behavior in shale gas development, as well as the relative contribution of each diffusion during different production stages. This work sheds light on the gas diffusion behavior over multiple pore sizes, which is beneficial for further quantitatively understanding shale gas transport in matrix during production.

    更新日期:2017-11-20
  • Fabrication of hierarchical MnMoO4⋅H2O@MnO2 core-shell nanosheet arrays on nickel foam as an advanced electrode for asymmetric supercapacitors
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Jiasheng Xu, Yudong Sun, Mingjun Lu, Lin Wang, Jie Zhang, Jianhua Qian, Xiaoyang Liu

    The hierarchical MnMoO4⋅H2O@MnO2 core−shell nanosheet arrays on nickel foam have been successfully fabricated by a mild two−step hydrothermal method. MnMoO4⋅H2O nanosheet arrays is synthesized by adding sodium molybdates solution into the manganese chloride solution containing a nickel foam, and followed by the first step hydrothermal treatment. The MnMoO4⋅H2O@MnO2 is fabricated by the second step hydrothermal treatment of above−step product in potassium permanganate solution. The core−shell nanosheet structure significantly increases the amount of active sites for redox reactions, shortens the diffusion pathway for ions and facilitates the effective penetration of the electrolytes for energy storage application. The MnMoO4⋅H2O@MnO2 as electrode material reaches to a high specific capacitance of 3560.2 F g−1 at a current density 1 A g−1, as well as advantageous cycling stability (84.1% capacitance retention after 10000 cycles). Furthermore, an asymmetric supercapacitor is also assembled, exhibiting an energy density of 45.6 Wh kg-1 at a power density of 507.3 W kg-1. The MnMoO4⋅H2O@MnO2 is a promising electrode material for supercapacitors.

    更新日期:2017-11-20
  • A facile VUV/H2O system without auxiliary substances for efficient degradation of gaseous toluene
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-20
    Yujie Zhan, Jian Ji, Haibao Huang, Miao He, Dennis Y.C. Leung, Shuilian Liu, Yajie Shu, Qiuyu Feng, Ruijie Xie, Ruimei Fang, Xinguo Ye

    Catalytic oxidation and AOPs normally require catalysts or chemical oxidants during VOCs degradation, making these processes costly and complex. We herein developed a facile system, VUV photolysis in pure water (VUV/H2O), for efficient VOCs degradation without auxiliary substances. The performance and mechanism of this system was intensively studied through controlling reaction conditions, detecting intermediates and analyzing reaction process during toluene degradation. Compared with direct VUV photolysis of gaseous toluene (VUV/Gas), the VUV/H2O system exhibited higher removal efficiency (83%) and mineralization rate (80%) of gaseous toluene bubbled into the system. In addition, no O3 and gaseous byproducts were detected in the outlet gas stream. The excellent performance of VUV/H2O was attributed to the generation of more ·OH from the VUV photolysis of water and the continuous degradation of accumulated intermediates dissolved in water. The high CO2 yield under an air atmosphere demonstrated that the dissolved oxygen in the water was essential for toluene mineralization since it was involved in the ring-fragmentation of toluene. According to various radicals and organic intermediates detected, possible pathway of toluene degradation in the VUV/H2O system was also proposed, which include OH addition, hydrogen abstraction and isomerization. The water after reaction can be effectively purified by sustaining VUV irradiation. This study presents a facile VUV/H2O system without auxiliary substances for efficient VOCs degradation and provides an insight into its degradation mechanism.

    更新日期:2017-11-20
  • Biomass-Derived N-Doped Porous Carbon as Electrode Materials for Zn-Air Battery Powered Capacitive Deionization
    Chem. Eng. J. (IF 6.216) Pub Date : 2017-11-17
    Cuijiao Zhao, Guoqiang Liu, Na Sun, Xian Zhang, Guozhong Wang, Yunxia Zhang, Haimin Zhang, Huijun Zhao

    Capacitive deionization (CDI) has been a promising technique to obtain fresh water by electrosorption of charged ionic species in seawater/brackish water. Its performance is highly dependent on the physical and chemical properties of CDI electrode materials. Herein, N-doped porous carbon (NPC) with a N content of 1.66 at.% was fabricated using soybean shell as starting material by a facile pyrolysis approach with the assistance of KHCO3 in N2 atmosphere. The as-prepared NPC with porous structure and high surface area (1036.2 m2 g-1) was further functionalized with sulfonic groups in an aryl diazonium salt solution to obtain sulfonyl functionalized NPC (S-NPC) with a surface area of 844.0 m2 g-1. S-NPC as cathode material was assembled into an asymmetric CDI device with aminated activated carbon (A-AC) as anode material, exhibiting superior CDI performance with an adsorption capacity of 15.5 mg g-1 and an average adsorption rate of 0.44 mg g-1 min-1 in 40 mg L-1 NaCl solution at an applied voltage of 1.2 V. As a proof of concept study, such configured CDI device was also powered for the first time by a Zn-air battery made from NPC with an open-circuit voltage of 1.28 V owing to N doping in soybean shell derived porous carbon with superior oxygen reduction reaction (ORR) activity, delivering an impressive CDI performance with an adsorption capacity of 15.8 mg g-1 and an average adsorption rate of 0.37 mg g-1 min-1 in 40 mg L-1 NaCl solution. This superior CDI performance can be due to S-NPC with high surface area, porous structure and surface rich negative charges resulted from sulfonyl functionalization, favourable for adsorption active sites exposure and mass transport of Na+ ions.

    更新日期:2017-11-20
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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