SN Applied Sciences
·
2019
·Vol. 1
·期 10
·1-11
·
IF 0
Geng Yuqing,Wang Zhiwei,Wang Yahuan,Song Jiayang,Chen Zhimin,Chen Jiafu,Chen Yong,Fu Jianwei
The development of excellent dye adsorbent with high adsorption capacity and good separation function is imperative to clean the wastewater. Herein, an innovative magnetic Fe–Fe 2 O 3 @poly(cyclotriphosphazene- co -polyethyleneimine) (named as Fe–Fe 2 O 3 @PCP) composite was fabricated through a facile copolymerization between hexachlorocyclotriphosphazene and polyethyleneimine in the presence of Fe–Fe 2 O 3 nanoparticles. With the help of scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscope and vibrating sample magnetometer, the microstructure of the resulting magnetic Fe–Fe 2 O 3 @PCP composite was characterized. Then, the adsorption performance of magnetic Fe–Fe 2 O 3 @PCP composite was evaluated by removing anionic dye acid chrome blue K (ACBK) from aqueous solution. The effects of contact time, initial solution pH and temperature on the adsorption of ACBK onto magnetic Fe–Fe 2 O 3 @PCP composite were systematically studied. The kinetics, isotherms and mechanism of the adsorption process were analyzed. Results show that the maximum adsorption capacity of the magnetic Fe–Fe 2 O 3 @PCP toward ACBK dye could be up to 260 mg g −1 at 25 °C in neutral solution. The adsorption kinetics follows both the pseudo-second-order kinetic model and the Weber’s intraparticle diffusion model well. And the Freundlich isotherm model can nicely fit the adsorption equilibrium data. The electrostatic attraction between Fe–Fe 2 O 3 @PCP and ACBK plays a dominant role in the adsorption process. Moreover, the magnetic Fe–Fe 2 O 3 @PCP composite owns a high saturation magnetization of 30.1 emu g −1 , rendering it rapid magnetic separability and good reusability. After five adsorption–desorption cycles, the magnetic composite still kept 75% of removal efficiency with the adsorption capacity of 195 mg g −1 . The excellent adsorption capacity and good magnetic separability make the magnetic Fe–Fe 2 O 3 @PCP composite a promising adsorbent for efficient removal of anionic dyes including ACBK from contaminated wastewater.
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FOOD SCIENCE AND BIOTECHNOLOGY
·
2019
·Vol. 29
·期 2
·217-226
·
IF 0.888
Tahir Haroon Elrasheid,Zhihua Li,Mahunu Gustav Komla,Xiaobo Zou,Arslan Muhammad,Xiaowei Huang,Yang Zhikun,Mariod Abdalbasit Adam
The marketability of blueberries over long distances has been limited because of their highly perishability. To prolong the postharvest shelf life and conserve quality properties of blueberry, various alternatives have been evaluated. We studied the influence of gum arabic (GA) alone or GA enhanced with African baobab (AB) fruit extract on blueberry during cold storage (4 °C) for 21 days. Physico-chemical properties (e.g. pH, color, firmness, and weight loss), microbial decay, antioxidant properties, polyphenol oxidase (PPO) and peroxidase (POD) activity were investigated. The fruit treated with GA combined AB indicated a significant delay in microbial decay, firmness loss, weight loss, and color change. The treatments on blueberries resulted in better preservation of total phenols and total anthocyanins delayed the increase in total soluble solids as compared to the control. The coatings lowered the activities of PPO and POD enzymes and delayed microbial decay in coated blueberry during 21 days of storage.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 55
·期 3
·990-996
·
IF 3.442
Yin Hang,Zhang Xudong,Lu Jiangwei,Geng Xuemin,Wan Yanfen,Wu Mingzai,Yang Peng
Chemical vapor deposition (CVD)-grown 2D materials like MoS 2 and WS 2 have been widely used for research and application. Here, we study substrates’ effects on CVD-grown MoS 2 and WS 2 . The morphology, crystalline quality and optical properties have been modified while changing substrates, which can be derived from lattice matching between 2D materials and substrate, defect/impurities on the interface and conductance/transparency of different substrates. The results provide suggestion for further study in CVD growth of 2D materials and device fabrications.
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高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2020
·Vol. 22
·期 1
·1-13
·
IF 2.132
Zhou Xin,Qu Qing,Wang Lin,Li Lei,Li Shunling,Xia Ke
A novel amine-modified carbon quantum dots (NH 2 -CQDs), which can act as a dual-detection probe for the ascorbic acid (AA) response, was synthesized. The product was obtained via facile and green hydrothermal carbonization of L-histidine. The high nitrogen to carbon ratio of L-histidine warrants a high nitrogen content of these CQDs, and thus to have more free electron pairs. This results in good electron transport capability. The NH 2 -CQDs with an average diameter of 3.67 ± 0.78 nm display blue fluorescence, with excitation/emission maxima at 340/420 nm, and a quantum yield of 15.9%. The fluorescence can be quenched by AA. Moreover, the NH 2 -CQDs can selectively detect AA with electrochemical detection. On the basis of the electrochemical and fluorescent properties of the NH 2 -CQDs, the electrochemistry method and fluorescence analysis for the detection of AA with a detection limit of 2.7 μM and 57 nM are developed. This finding may provide a dual-detection platform, which can be used as a potential candidate for more selective to detect AA in pharmaceuticals, clinics, and food industries.
Schematic representation of the synthesis strategy of amine-modified carbon quantum dots (NH 2 -CQDs) and their electrochemical and fluorescent response to ascorbic acid (AA).
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高影响因子
Frontiers of Environmental Science & Engineering
·
2019
·Vol. 14
·期 2
·1-16
·
IF 3.883
Wang Xiangyu,Xie Yu,Yang Guizhen,Hao Jiming,Ma Jun,Ning Ping
The secondary pollution caused by modification of an electrode due to doping of harmful materials has long been a big concern. In this study, an environmentally friendly material, conductive carbon black, was adopted for modification of lead dioxide electrode (PbO 2 ). It was observed that the as-prepared conductive carbon black modified electrode (C-PbO 2 ) exhibited an enhanced electrocatalytical performance and more stable structure than a pristine PbO 2 electrode, and the removal efficiency of metronidazole (MNZ) and COD by a 1.0% C-PbO 2 electrode at optimal conditions was increased by 24.66% and 7.01%, respectively. Results revealed that the electrochemical degradation of MNZ wastewater followed pseudo-first-order kinetics. This intimates that the presence of conductive carbon black could improve the current efficiency, promote the generation of hydroxyl radicals, and accelerate the removal of MNZ through oxidation. In addition, MNZ degradation pathways through a C-PbO 2 electrode were proposed based on the identified intermediates. To promote the electrode to treat antibiotic wastewater, optimal experimental conditions were predicted through the Box-Behnken design (BBD) method. The results of this study suggest that a C-PbO 2 electrode may represent a promising functional material to pretreat antibiotic wastewaters.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 24
·14872-14883
·
IF 3.442
Wang Yunpeng,Ma Bo,Chen Yantao
Development of inexpensive and high-performance electrocatalysts for water splitting is the major challenge for the scale-up production of gaseous hydrogen. Iron foam, which is composed of the second most abundant metal element on the earth, can boost the water splitting reactions after a simple treatment of surface phosphorization. The as-prepared electrocatalyst, which is denoted as FeP x @Fe, exhibits an excellent activity in alkaline solutions, and requires overpotentials of 124 and 274 mV to approach 10 mA cm −2 for hydrogen evolution reaction and oxygen evolution reaction, respectively. Meanwhile, FeP x @Fe also shows a remarkable performance on overall water splitting, which only needs 1.67 V to reach 10 mA cm −2 and exhibits a satisfying long-term durability. The fabrication strategy of surface phosphorization on iron foam to obtain FeP x @Fe can be valuable for the application of non-noble-metal electrocatalysts toward water splitting.
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高影响因子
CHEMICAL PAPERS
·
2019
·Vol. 74
·期 6
·1717-1727
·
IF 1.246
Wang Jun,Wang Yan,Liu Xin-Xin,Li De-Ming,Li Sui-Xin
Determination of pyraclostrobin in ginseng samples by molecularly imprinted dispersive solid-phase extraction (MIDSPE) coupled with high-performance liquid chromatography (HPLC) method was developed. Molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using pyraclostrobin as template, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) and azobisisobutyronitrile (AIBN) as cross-linker and initiator, respectively. The mixture of butanone (MEK) and n -heptane (7:3, V:V) was used as solvent and porogen. The microspheres were characterized by laser particle size analyzer, scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). Binding experiments showed high binding capacity of polymers, and that the maximum adsorption of MIPs and NIPs to pyraclostrobin was 73.01 mg g −1 and 59.14 mg g −1 . Selective adsorption experiments verified that polymers had specific and selective recognition site for pyraclostrobin. Comparing MIPs with C 18 , the recoveries of pyraclostrobin from blank ginseng samples spiked at 0.05, 0.1, and 1.0 mg kg −1 ranged between 77.6% and 93.5% with the standard deviation of 2.18–6.07 and the relative standard deviations (RSDs) between 2.47 and 6.99% ( n = 5). The recoveries of pyraclostrobin that used C 18 as sorbent were found to be 53.04–63.86% with the standard deviation of 1.13–2.83 and the relative standard deviations of 1.07–4.99%. The data indicated that the method for the analysis of the pyraclostrobin in ginseng samples can achieve good recoveries, repeatability and reproducibility. The linear regression equation was calculated as y = 2.09935e−006 x + 0.0176235 ( R 2 = 0.998656). The limit of detection (LOD, S/N = 3) was 0.01 mg kg −1 . The confidence interval for the slope at the 95% confidence level was [356084.1828, 899542.8563], and the confidence interval for the intercept was [− 755349.2710, 72645.0856]. The MIDSPE-HPLC method showed specific selective separation and enrichment of trace pyraclostrobin in ginseng samples. The raw samples were tested and results were all below the maximum Residue Limit (MRL) 0.1 mg kg −1 in the European Union.
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高影响因子
JOURNAL OF POROUS MATERIALS
·
2019
·Vol. 27
·期 1
·249-261
·
IF 1.947
Nie Tianming,Yuan Zhangyu,Yin Shuang,Tu Weiran,Yan Weilin,Gao Jiajun,Jiang Xingmao
Crosslinking polystyrene (CPS), which is an inexpensive porous resin synthesized by waste polystyrene and CCl 4 , can be precursor for carbon material. Carbonization with KOH or steam activation was usually needed for the carbonization, but that without any activation was rarely reported. By the carbonization (room temperature to 900 °C; heating rate of 3 °C/min; N 2 atmosphere), the carbon prepared had no pores. Interestingly, the carbonization modified by five temperature platforms (150 °C, 200 °C, 300 °C, 400 °C and 500 °C) before 900 °C can produce the porous carbon with high surface area ( S BET = 849 m 2 /g) and rich micropores ( V mic = 0.306 cm 3 /g). The thermal behavior of the CPS was studied under different carbonization conditions. The temperature platforms that made the heating milder was found to be crucial for the porous structure. They promoted the hydrolysis of Ph 2 CCl 2 to Ph 2 C=O stabilizing the skeleton and slowed down the escape of the pore-creating substances, i.e., Ph 2 C=O, PhCOOH and –[CH–CH 2 ] n –. Thereby, the carbonization with the temperature platforms not only kept the pores but also constructed the new pores. Moreover, the porous carbon prepared had the rich micropores from 0.6 to 0.8 nm and from 1.0 to 1.2 nm, showing a high S-capacity (34.2 mg S/g) for the adsorption of dibenzothiophene from oil.
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高影响因子
TRIBOLOGY LETTERS
·
2020
·Vol. 68
·期 1
·1-11
·
IF 2.566
Yang Ye,Liu Tengfei,Dai Yuanjing,Wang Yan,Zhang Chenhui
This work investigates the effect of amines on the lubricity of castor oil-sulfated sodium salt (CSS) emulsion solution for titanium alloys. It is found that the amines with hydrophilic parts such as diglycolamine, have a negative effect on the lubrication while those with hydrophobic parts such as dicyclohexylamine (DCHA), show a synergistic effect when they are mixed with the CSS. The mechanisms of both the synergistic and negative effects of amines are investigated. The quartz crystal microbalance with dissipation-monitoring results show that the ammonium salt with hydrophobic parts such as DCHA can form a strong adsorption film on the titanium surface. These findings indicate that the amines with hydrophobic parts can be used as a pH regulator and corrosion inhibitor for developing an effective cutting fluid for titanium alloys.
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2020
·Vol. 412
·期 4
·993-1002
·
IF 3.637
Li Wenshuai,Huang Saipeng,Wen Huiyun,Luo Yane,Cheng Jiewei,Jia Zhao,Han Pu,Xue Weiming
The nitrite ion (NO 2 − ) is a vital inorganic species that occurs both in natural ecological systems and human bodies. The high concentration of NO 2 − can be harmful for animal and human health. It is important to develop a simple, sensitive, reliable, and economic methodology to precisely monitor NO 2 − in various environmental and biological fields. Thus, a novel nitrite biosensor based on carbon quantum dots (PA-CDs) has been constructed and prepared via a high-efficiency, one-pot hydrothermal route using primary arylamines (PA) such as m -phenylenediamine. The device exhibits bright green fluorescence and a high quantum yield of 20.1% in water. In addition, the PA-CDs also possess two broad linear ranges: 0.05–1.0 μM and 1.0–50 μM with a low detection limit of 7.1 nM. The classical diazo reaction is firstly integrated into the PA-CD system by primary arylamines, which endows the system with high sensitivity and specific selectivity towards nitrite. Importantly, the nanosensor can detect NO 2 − in environmental water and serum samples with high fluorescence recoveries, demonstrating its feasibility in practical applications. This work broadens a new method to fabricate novel nanosensors and provides a prospective application for fluorescent carbon quantum dots (CDs).
Graphical abstract
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高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 1
·147-163
·
IF 2.014
Shao Jun,Xu Lanli,Pu Shouzhi,Hou Haoqing
Blending of poly( l -lactide) and poly( d -lactide) (PLLA, PDLA) results in the formation of poly(lactide) stereocomplex crystallites (SC). For the preparation method, numerous reports employed solution mixing and stirring to receive a product with uniform performance. However, the effect of stirring time during solution mixing on the subsequent crystallization behavior did not clear yet, and which is important for solution crystallization, casting and spinning. In this paper, linear PLLA and PDLA with various molecular weights were synthesized. The PLLA and PDLA solutions were mixed together and stirred for different times before casting. Results revealed that the structures of PLA SC and homochiral crystallites (HC) did not vary with change in the stirring time. More amount of content of SC with uniform structure and less amount of content of HC were produced in the specimens stirred for longer time. When the specimens crystallized either from the melt or from the melt-quenching, less amount of content of crystallites (total crystallinity of SC and HC) was produced and the melting temperature of SC and HC depressed in the specimens that were stirred for longer time. With the increase in molecular weights, the effect of stirring time on the crystallization behaviors declined. This investigation provides a route to tailor the crystallization behavior of PLLA/PDLA specimens.
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高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 2
·1-7
·
IF 6.232
Wang Jiawei,Ni Pengjuan,Chen Chuanxia,Jiang Yuanyuan,Zhang Chenghui,Wang Bo,Cao Bingqiang,Lu Yizhong
Core-shell palladium cube@CeO 2 (Pd cube@CeO 2 ) nanoparticles are shown to display oxidase-like activity. This is exploited in a method for determination of the activity of alkaline phosphatase (ALP). The Pd cube@CeO 2 nanoparticles were thermally synthesized from Ce(NO 3 ) 3 , L-arginine and preformed Pd cube seeds in water. The Pd cube@CeO 2 nanoparticles catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by oxygen. This results in the formation of oxidized TMB (oxTMB) with an absorption peak at 652 nm. Ascorbic acid (AA) is generated from the hydrolysis of L-ascorbic acid 2-phosphate (AAP) catalyzed by ALP. It can reduce oxTMB to TMB, and this results in a decrease of the absorbance. The method allows for quantitative determination of the activity of ALP in the range from 0.1 to 4.0 U·L −1 and with a detection limit down to 0.07 U·L −1 . Endowed with high sensitivity and selectivity, the assay can quantify ALP activity in biological system with satisfactory results.
Schematic illustration of Pd cube@CeO 2 core-shell nanoparticles for colorimetric determination of alkaline phosphatase.
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高影响因子
危险品化学品经营许可证（带存储）