SENSORS AND ACTUATORS B-CHEMICAL
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2019
·
IF 6.393
Yanling Shen,Hong Yan,Hua Guo,Yumei Long,Weifeng Li
A new electrochemical sensor has been developed for the simultaneous determination of 4-aminophenol (4-AP) and phenol (Ph) based on the defect-rich hexagonal boron nitride (D-h-BN). The D-h-BN was prepared via one-step calcination route using a single-source precursor. The obtained D-h-BN was structurally characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). Photoluminescent (PL) result suggested that the as-synthesized h-BN was highly defective. More interestingly, such D-h-BN exhibited favorable electrocatalytic activity in the redox reaction of Ph and 4-AP, which was confirmed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements. The enhanced electrocatalytic activity of D-h-BN was attributed to its large surface-active sites and fast electron transfer mediated by defect structure. Thus, D-h-BN was employed to modify glassy carbon electrode (GCE) without any binder agents and the as-fabricated sensor showed good electrochemical performances in the simultaneous determination of 4-AP and Ph. By using DPV method, the linear detection ranges between concentrations and current intensities for 4-AP and Ph were 0.01–30 and 0.1–30 μM, respectively, and their detection limits (S/N = 3) were estimated to be 0.003 and 0.035 μM. Moreover, the desirable selectivity and reproducibility make the proposed method successfully applied for real sample assay.
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高影响因子
SOLID STATE SCIENCES
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2019
·
IF 2.155
Jinyi Zhang,Jing Zuo,Yinshan Jiang,Dandan Zhu,Jiupeng Zhang,Cundi Wei
Coal gasification slag is abundant of unburned carbon and inorganic matters such as silica , alumina and calcium oxide. The mesoporous structure of coal gasification slag can be produced by acid leaching of metal ions. Therefore, it is very important to study the acid leaching process of coal gasification slag. At the same time, in order to broaden the application fields of coal gasification slag, the thermal stability of the as-prepared pore structure should meet the requirements of various occasions. Using coal gasification coarse slag (CS) and coal gasification fine slag (FS) as raw materials, this study investigated the kinetic characteristics of mesoporous formation and optimized the acid leaching conditions. The results of BET, BJH, SEM, XPS and chemical tests showed that under the condition of acid-ash ratio (molar ratio) of 1.0, liquid-solid ratio (volume/mass) of 4:1 and acid leaching temperature of 90 °C, the formation of mesoporous structure by acid leaching was a process of first-order kinetic reaction. According to the analysis of XRD , it was found that the thermal stability of both CS and FS had been greatly improved after acid leaching because of the siliceous enrichment.
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高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 6
·065405
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IF 1.449
Qinghong You,Miaomiao Wan,Xiaoxu Fang,Xiulian Yin,Chuping Luo,Xuejuan Zhang
The process of intermittent microwave extraction (IME) pectin from pomelo peels assisted with EDTA was optimized by response surface methodology. Results showed that the optimal process for intermittent microwave extraction of pectin was as follows: 0.25% EDTA, pH 1.0, solid-to-liquid ratio 1:25 g ml−1, extraction time 125 s, microwave power 550 W, the extraction yield of pomelo peels was (38.48 ± 0.28)%. The structure of three kinds of pectin was verified by IR, SEM, XRD, HPLC and the results showed that pectin obtained from IME had a poor solubility but a good emulsifying activity. The IUEP had the highest scavenging rates of DPPH radicals.
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高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Nisakorn Saengprachum,Dongren Cai,Mantian Li,Ling Li,Xiaocheng Lin,Ting Qiu
Via the crosslinking of chitosan and sulfosuccinic acid (SSA), the acidic chitosan membrane (ACM) was prepared for biodiesel production from esterification of oleic acid and methanol. ATR-FTIR, TGA, XRD, SEM and EDX were applied to characterize the prepared ACM. The acidic site density and swelling capacity of the prepared ACM were investigated. The ACM possessed the 4.62 mmol/g of acidic site density, which was just a little less than 4.76 mmol/g of Amberlyst-15, meanwhile, ACM was proven to be much higher than Amberlyst-15 in swelling capacity. Under the same reaction, the 98.76% of conversion can be obtained while the Amberlyst-15 only reached 44.30%. The optimization of process variables was conducted by the combination of single factor experiment and Box-Behnken design (BBD) response surface methodology . The catalytic activity of ACM in different esterification of fatty acids and alcohols was also investigated. And the catalytic mechanism of esterification catalyzed by ACM was clarified. Based on the catalytic mechanism, the kinetic model was established to describe the esterification and obtain relevant kinetic parameters ( E a + , E a − , A + and A - ), meanwhile, the kinetic results were compared to the same reaction with different catalysts in detail. Besides, the reusability of the prepared ACM was studied.
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高影响因子
HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Huagao Wang,Hailong Tang,Junyi Yang,Youbing Li
Poly(arylene ether nitrile)s (PAENs) play an important role in special engineering materials owing to their excellent mechanical strength and superior thermal stability. In this study, PAEN and carboxyl-functionalized poly(arylene ether nitrile) (CPAEN) were successfully synthesized and their thermal parameters were determined through thermogravimetric analysis and differential scanning calorimetry to investigate the thermal decomposition kinetics and thermal stability. The results indicate that both PAEN and CPAEN exhibited high glass transition temperature and initial decomposition temperature. Meanwhile, the effects of the side groups on the thermal stability and the decomposition kinetic parameters of PAEN and CPAEN under nitrogen were discussed systematically. The kinetic parameters of PAEN and CPAEN were determined using the Kissinger and Ozawa methods, respectively. It reveals that the activation energy (E) values of PAEN obtained using the Kissinger and Ozawa methods were 192.45 and 206.63 kJ/mol, and the corresponding E values of CPAEN were 161.20 and 162.72 kJ/mol, respectively. The thermal decomposition mechanism of PAEN and CPAEN obtained from Coats–Redfern methods goes for F 3 and D 1 models, respectively.
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CHEMICAL ENGINEERING JOURNAL
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2018
·
IF 6.735
Zu-Sheng Huang,Yun-Yun Quan,Jia-Jun Mao,Yi-Li Wang,Yuekun Lai,Jing Zheng,Zhong Chen,Kun Wei,Huaqiong Li
Superhydrophobic materials have attracted immense commercial and academic interests in recent years. However, the poor mechanical durability has restricted their practical applications where high durability is required. Here, a facile one-pot synthesis method was reported to fabricate multifunctional superhydrophobic composite materials with remarkable mechanochemical robustness, stain repellency, oil-water separation and sound-absorption. Their mechanical and chemical durability could be greatly improved by chemically adhering epoxy resin microspheres (ERMs) on 3-D porous skeleton structures of latex sponge. The materials could retain superhydrophobicity after going through sandpaper abrasion, ultrasonication, multiple knife scratch, tape peeling and finger wiping, and exposure to UV irradiation and high temperature. The materials are able to maintain the repellency against strong acid and alkali droplets. The combined excellent mechanical properties, liquid repellency & selectivity , and other functional properties displayed by this type of material have made it a strong candidate for a range of industrial applications.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2018
·Vol. 135
·期 31
·46593
·
IF 1.901
Li Yang,Ting Wang
Cyclodextrin-grafted cellulosic hydrogel beads (CD + @HEC-CMC-gel) were prepared through electrostatic and host–guest interactions. β-Cyclodextrin (CD + ) modified with quaternary ammonium groups was used as the electropositive binding site, and carboxymethyl cellulose (CMC) in a double-network hydrogel structure was used as the electronegative binding site. The double-network structure was obtained by controlling the crosslinking of CMC and hydroxyethyl cellulose (HEC) in the presence of epichlorohydrin. The electrostatic interaction was used to graft CD + onto the electronegative double-network structure. Scanning electron microscopy indicated an obvious change in the cellulosic double network after grafting of CD + . The grafting content of CD + in CD@HEC-CMC-gel is determined as 93.10 ± 0.74% by the photometric titration method. In order to evaluate the assembling and releasing ability, ibuprofen (IBU) was selected to be encapsulated in CD + @HEC-CMC-gel by host–guest interaction. In addition, the release of IBU by the hydrogel beads was explained by several kinetic models. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46593.
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高影响因子
ANALYST
·
2018
·Vol. 143
·期 23
·5812-5821
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IF 3.864
Xiaohua Pan,Yan Zhang,Xiaobo Sun,Wei Pan,Jinping Wang
Since different quenching mechanisms can endow carbon dots (CDs) with diverse responsive manners, multi-mode sensing can in principle be achieved by a single carbon-dot-based sensor. In this work, green emissive CDs were prepared by simple hydrothermal pyrolysis of phenolphthalein and ethylenediamine at 180 °C for 5 h, with a quantum yield of 17%. The as-prepared CDs can be selectively quenched by Hg2+ due to their specific binding affinity causing photo-induced electron transfer (PET). Due to the inner filter effect (IFE), the CDs also showed intensive fluorescent response to lemon yellow dye. Moreover, the CDs responded to Fe2+ or H2O2 selectively in the presence of H2O2 or Fe2+ owing to oxidative quenching (OQ) by hydroxyl radicals resulting from the Fenton reaction. Via the diverse responsive manners of PET, IFE and OQ, multi-mode sensing for Hg2+, lemon yellow and Fe2+, H2O2 was thus achieved by a single green emissive carbon-dot-based sensor. Accordingly, the linear ranges for the selective detection of Hg2+, lemon yellow, Fe2+ and H2O2 were found to be 0.0–500.0, 0.0–20.0, 0.0–90.0 and 0.0–50.0 μM, with the limits of detection as low as 5.8, 0.5, 1.2 and 1.1 μM, respectively.
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PubMed
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
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2013
·Vol. 169
·期 6
·1811-1821
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IF 1.893
Wang Ting,Li Bin,Lin Li
A novel functional material of β -cyclodextrin ( β -CD) grafting cellulose beads containing immobilized silver nanoparticles (AgNPs) is presented in this paper. The morphology was characterized by scanning electron microscopy, energy-dispersive X-ray, and X-ray photoelectron spectroscopy. Phenolphthalein probe molecule technique was used to detect the activity of the grafting β -CD, and the results demonstrated that the deposition of AgNPs had no influence on its encapsulation ability. Acid resistance of the AgNPs on the bead material was studied by atomic absorption spectrometry. The stability of the AgNPs was enhanced due to the grafting of β -CD. Tube dilution method was applied to study the bacteriostatic effect, and the minimal inhibitory doses of the novel material against Escherichia coli and Staphylococcus aureus were 12.5 and 25 mg, respectively. The minimal bactericidal doses for the two bacteria were 25 and 25 mg, respectively.
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PubMed
高影响因子
WOOD SCIENCE AND TECHNOLOGY
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2012
·Vol. 47
·期 3
·601-613
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IF 1.727
Si Hongyan,Li Bin,Wang Ting,Lin Li,Xu Zuwei
Poplar wood flour, a low-cost and abundantly available material, was modified by grafting β -cyclodextrin ( β -CD) in the presence of citric acid or 1,2,3,4-Butanetetracarboxylic acid, aiming to expand the application of wood flour. The products were characterized by Fourier transform infrared spectroscopy and the technique of phenolphthalein probe. The grafting conditions of β -CD onto wood flour including curing temperature, β -CD concentration in impregnation solution and catalyst were also evaluated by the technique of phenolphthalein probe. Besides, eugenol (EG), an antibacterial fragrant guest molecule, was loaded on the modified wood flour by lyophilization, and its release characteristics were investigated by Thermo-gravimetric. The results revealed that the modified wood flour material had a thermo-protective effect on the volatilization of EG and the encapsulated EG content was reached to 1.31 %, which could demonstrate a potential application in the finishing and packing areas.
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CHEMICAL ENGINEERING SCIENCE
·
2014
·
IF 2.613
Zhichang Liu,Pengcheng Hu,Xianghai Meng,Rui Zhang,Huiqing Yue,Chunming Xu,Yufeng Hu
Switchable polarity ionic liquids (SWILs) with low moisture sensitivity were successfully synthesized from organic amidine/fluoroalcohol and guanidine/fluoroalcohol via proton transfer reaction. The ionic liquids showed low polarity and could be converted into high-polarity fluoroalkylcarbonate ILs upon the treatment with CO 2 under mild conditions. Their high polarity state could also readily be reverted to the low polarity state by the removal of CO 2 with heating. Changes in the structures and physical properties resulting from the change from low polarity to high polarity were confirmed by NMR spectroscopy, FTIR spectrophotometry , UV–vis spectroscopy, and conductivity and miscibility measurements. These SWILs have potential applications in solute separation and solvent recovery.
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高影响因子
FLUID PHASE EQUILIBRIA
·
2014
·
IF 2.241
Ye Yuan,Yixin Leng,Hui Shao,Chunxiang Huang,Kai Shan
The solubility of dl -malic acid in water, ethanol and ethanol + water mixtures was investigated by a static analytical technique using the acid–base titration method at temperatures ranging from 298.15 to 333.15 K. The experimental results indicated that the solubility of dl -malic acid in the binary solvent mixtures increases with increasing temperature and decreases with increasing mass fraction of ethanol. The measured solid–liquid equilibrium (SLE) data were correlated by the modified Apelblat, λh and van’t Hoff equations. The calculated solubility demonstrated good agreement with the experimental data. It was found that the modified Apelblat equation could give the best correlation results, and subsequently used to derive the standard enthalpy, entropy and Gibbs energy change of solution of dl -malic acid in ethanol + water binary mixtures.
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