Analytical Methods
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2018
·Vol. 10
·期 35
·4251-4256
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IF 2.073
Wen Jie Zhang,Shi Gang Liu,Lei Han,Yu Ling,Liu Li Liao,Shi Mo,Hong Qun Luo,Nian Bing Li
A facile, low-cost, and effective sensing strategy for detection of picric acid (PA) was developed based on copper nanoclusters (CuNCs). In this strategy, highly fluorescent CuNCs were prepared by using copper nitrate and ascorbic acid through an environmentally friendly process. Also, the PA-induced fluorescence quenching mechanism was investigated through ultraviolet-visible absorption spectra, fluorescence spectra, and fluorescence lifetimes, and might be ascribed to the molecular interactions and the strong inner filter effect between the CuNCs and PA. Under the optimal conditions, the fluorescence quenching degree of as-synthesized CuNCs was linearly dependent on the concentration of PA within a wide linear range of 2–40 μM, and the limit of detection was 0.98 μM. Finally, the proposed method was successfully applied to detect the levels of PA in real water samples.
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Chemical Engineering and Processing-Process Intensification
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2018
·
IF 2.826
Congfei Yao,Yucui Hou,Shuhang Ren,Youan Ji,Weize Wu,Hui Liu
Four kinds of dual-functionalized ionic liquids (DFILs, [Et 2 NEmim][Cl] 2 , [Et 2 NEmmor][Cl] 2 , [Et 2 NEmpyr][Cl] 2 and [Et 2 NEmpic][Cl] 2 ) were synthesized and used to efficiently separate phenolic compounds from model oils. The effects of stirring time, temperature, mole ratio of DFIL to phenol and initial phenol content on the separation were investigated. The results indicate that at a DFIL:phenol mole ratio of 0.3, the content of phenol in the oil phase can reach the minimum value and the extraction efficiency of phenol is more than 96%. The minimum phenol content in the oil phase and the best phenol extraction efficiency were 5.9 g/m 3 and 98.5%, respectively, when [Et 2 NEmpyr][Cl] 2 was used. Compared with traditional ionic liquids, these DFILs not only reduce the dosage of extraction agents but also greatly decrease the content of Cl − in the oil phase due to the double anion in the DFILs. The DFILs can be reused for 4 cycles without losses in phenol extraction efficiency and masses of the DFILs. The separation mechanism of extraction was studied using FT-IR. The result indicates that the two anions Cl − on DFILs can form a hydrogen bond with phenol.
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JOURNAL OF CHROMATOGRAPHY A
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2018
·
IF 3.716
Yanlong Chen,Wenfen Zhang,Yanhao Zhang,Zhifen Deng,Wenjie Zhao,Huifang Du,Xue Ma,Dan Yin,Fuwei Xie,Yu Chen,Shusheng Zhang
This study reports a novel strategy for the preparation of porous aromatic framework (PAF-6) coated magnetic nanoparticles (PAF-6 MNPs) using cyanuric chloride as a planar trigonal basis upon which to build a linear piperazine linker unit. The PAF-6 MNPs were examined as an efficient solid-phase extraction (SPE) sorbent for enrichment of trace organic pollutants including phenol, 2,4,6-trinitrophenol, naphthalene, naphthol, bisphenol A, 2,4-dichlorophenol and 3-nitrochlorobenzene in water. The high-performance liquid chromatography detection limits of such analytes were in the range of 0.08–5.02 ng/mL and recoveries were found to be 84.0–94.0% in well water, tap water, river water and wastewater. The main toxic components of cigarette smoke, including phenolic compounds and benzo[a]pyrene, are efficiently adsorbed by PAF-6 MNPs, and over 50% of such toxins are removed. Theoretical computations were performed to understand the molecular interaction mechanism between PAF-6 and such analytes. The results demonstrate that the PAF-6 MNPs sorbents show excellent adsorption of phenols, polycyclic aromatic hydrocarbons and nitroaromatics based on multiple π-π stacking and hydrogen-bond interactions. These results suggest that the PAF-6 MNPs can be applied to extraction, removal and determination of diverse trace multi-target analytes from complex media.
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RSC Advances
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2018
·Vol. 8
·期 30
·16603-16610
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IF 2.936
Fangfang Li,Fengyi Wang,Xuan Hu,Baozhan Zheng,Juan Du,Dan Xiao
The detection of nitroaromatic explosives is important due to their strong explosive force and harmfulness in the environment, and for homeland security and public safety. Herein, a phosphorescence CaTiO3:Pr3+@SiO2 nanosensor was successfully developed for the sensitive and selective detection of 2,4,6-trinitrophenol (TNP). The red-emitting phosphorescent chemosensor CaTiO3:Pr3+@SiO2 possessed a long enough phosphorescence lifetime of 0.016 s. The TNP induced phosphorescence quenching process of CaTiO3:Pr3+@SiO2 presented a wide linearity with TNP concentrations ranging from 0.5 to 100 μM, and the detection limit was found to be 20.6 nM. Furthermore, this sensor displayed a high selectivity toward TNP over other structurally similar compounds like 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), 4-nitrotoluene (NT), 2,4-dinitrophenol (DNP), 4-nitrophenol (NP) and phenol. This sensing system was successfully used in the test of TNP concentrations in water samples, and showed great potential for practical application.
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POLYMER DEGRADATION AND STABILITY
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2018
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IF 3.193
Niya Ye,Yixin Xu,Dengji Zhang,Jingshuai Yang,Ronghuan He
We employed four radical inhibitors to investigate their influences on the degradation of poly (4-vinylbenzyl chloride-styrene) based anion exchange membranes (AEMs) in alkaline solutions. It is found that the presence of the radical inhibitors could effectively restrain the nucleophilic attack of hydroxide ions to the AEMs according to the conductivity measurements, especially the one p -ethyl phenol (PEP), which could significantly protect the AEMs against the attack. More evidences including water uptake, swelling ratio as well as FT-IR analysis further proved this phenomenon by comparison those properties of the membranes before and after the stability test in 8 M KOH at 80 °C for 24 h. According to the 1 H NMR spectra, the quaternary ammonium groups of the AEMs were mainly degraded into tertiary amines in the hot alkaline solutions; while in the presence of PEP, this degradation was restrained and the quaternary ammonium groups maintained by reaction with PEP. Fenton test results further indicated that high oxidative stability of the AEMs benefited from the presence of a small amount of PEP, which could reduce the generation of the oxidants. Thus an inhibition reaction mechanism of the radical inhibitors preventing the AEMs from alkaline degradation is proposed.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
·
IF 3.141
Weiping Kong,Yong Liu,Fujian Liu
Efficient micro-meso-macroporous solid acids spheres with controllable acid strength were successfully synthesized by simultaneous grafting of −SO3H and −SO2CF3 onto the network of commercial XAD-4 resin. The synthesized solid acids are designated as XAD-4-SO3H and XAD-4-SO3H-SO2CF3. Various characterizations show that XAD-4-SO3H and XAD-4-SO3H-SO2CF3 possess high BET surface areas, hierarchical porous structures with combined micro-meso-macropores, high concentrations of acid sites, and strong acid strength. Catalytic tests show that XAD-4-SO3H and XAD-4-SO3H-SO2CF3 exhibit superior activities and good reusability in various acid-catalyzed reactions including esterification of acetic acid with cyclohexanol, acylation of anisole with acetyl chloride, and catalytic synthesis of bisphenol A. Their activities were better than the solid acids of Amberlyst-15, SBA-15-SO3H-0.1, H3PW12O40, and acidic zeolites. This work develops a new method for scalable transformation of commercially macroporous resin into efficient porous solid acids, which promotes their wide use in industrial catalysis.
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ANALYTICAL SCIENCES
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2018
·Vol. 35
·期 2
·147-152
·
IF 1.355
Ju Yan Jun,Li Na,Liu Shi Gang,Fan Yu Zhu,Ling Yu,Xiao Na,Luo Hong Qun,Li Nian Bing
A fluorescence method for the determination of picric acid (PA) using phosphorus-doped carbon dots (P-CDs), synthesized from β-cyclodextrin and sodium pyrophosphate, is described. The P-CDs are very uniform and monodisperse with a diameter of about 2.8 nm. Under an excitation of 350 nm, the P-CDs emit bright blue fluorescence with an emission peak at 440 nm. The as-synthesized P-CDs serve as a sensitive, selective, and label-free fluorescent probe for the detection of PA. Based on an inner filter effect between PA and P-CDs, a linear response is obtained for PA from 0.1 to 10 μM with a detection limit of 82 nM. Finally, this sensing system has been demonstrated to have practicability for PA detection in the environmental water samples.
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PROCESS BIOCHEMISTRY
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2018
·
IF 2.616
Feng Xue,Xiangju Ya,Qi Tong,Yuansong Xiu,He Huang
A new halohydrin dehalogenase-like gene (HHDH) in the genome of Pseudomonas umsongensis YCIT1612 was identified, cloned and over-expressed in Escherichia coli . HHDH-Pu exhibited the highest sequence identity of 45% in comparison with the previously reported HHDHs. The recombinant HHDH-Pu was purified to homogeneity and its catalytic characteristics in epoxide ring opening was explored. Compared to other reported HHDHs, HHDH-Pu showed higher catalytic activity, exhibiting varied activities (2.4–50.4 U/mg) toward all the tested epoxides. It catalyzed the ring opening of epoxides with low to moderate enantioselectivity ( E =1.13-10.89). Rac- PGE was found to be the most selective among the tested epoxides. In the ring opening of rac -PGE, nucleophiles such as Cl − , N 3 − , NO 2 − , Br − or SCN − were accepted. N 3 − was selected as the optimal nucleophile. Some parameters that may alter this bio-resolution, such as the concentration of N 3 − , temperature and pH were evaluated. By optimizing the reaction conditions, the residual ( S )-PGE could be obtained in 23.5% yield and more than 99% ee from 40 mM rac -PGE.
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JOURNAL OF CEREAL SCIENCE
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2018
·
IF 2.302
Kuijie Gong,Lirong Chen,Xiaoyue Li,Linlin Sun,Kaichang Liu
A combination of germination and extrusion was applied to whole grain corn to increase its nutritional composition, functional properties and non-anthocyanin polyphenol profile, especially related to in vitro hypoglycemic effects. Individual germination and extrusion both led to an increase in soluble dietary fiber and lysine, methionine , tryptophan content, while insoluble dietary fiber content decreased. Extruded germinated whole corn flour (EGWCF) had a higher water absorption and solubility index, showing 103 and 575% increases over untreated ones, respectively. Germination increased free, bound phenolic acid and bound flavonoid content to 169, 230 and 311%, respectively. The total phenolic acid and flavonoid content of EGWCF was 260 and 249% of WCF, respectively. Germination increased the polyphenol composition from 12 to 15 species. Phenolic profiles of EGWCF exhibited collective effects, showing three new phenolic compounds . Polyphenol extracts showed more potent activity against α -glucosidase rather than α -amylase. Free form polyphenols had stronger inhibitory activity than the bound forms. Compared with WCF, free and bound polyphenol extracts from EGWCF increased the anti- α -glucosidase activity by 221 and 40%, and increased the anti- α -amylase activity by 105 and 108%.
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APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Yuxue Zhou,Pengfei Lv,Wei Zhang,Xiangdong Meng,Hui He,Xianghua Zeng,Xiaoshuang Shen
Pristine Bi 2 WO 6 hollow microspheres have been fabricated in ethylene glycol-water system with CTAB as crystal growth director for the first time, hybrid Au- Bi 2 WO 6 hollow microspheres was also obtained by in situ decoration of Au nanoparticles, the formation mechanisms were explored. Their photocatalytic activities on photo-reduction of Cr(VI) and photo-degradation of phenol in aqueous solution were investigated under visible light irradiation. Hybrid Au- Bi 2 WO 6 hollow microspheres displayed the highest photocatalytic activity, exhibiting a nearly complete reduction of Cr(VI) to Cr(III) within only 20 min. The excellent photocatalytic activities of heterogeneous Au-Bi 2 WO 6 hollow microspheres can be induced by the increased light harvesting efficiency (due to light multi-scattering effect of hollow architecture), high separation of photogenerated electron-hole pairs caused by electron trapping effect and surface plasmon resonance (SPR) effect of Au nanoparticles.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2018
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IF 2.88
Huanhuan Fan,Guo Qiang Xiang,Yule Wang,Heng Zhang,Keke Ning,Junyue Duan,Lijun He,Xiuming Jiang,Wenjie Zhao
In the present work, a selective and sensitive method for detecting TNP using manganese doped carbon quantum dots (Mn-CDs) was developed. The Mn-CDs were prepared via a simple hydrothermal method using 1-(2-pyridinylazo)-2-naohthalenol naohthalenol (PAN) and MnCl 2 as precursors. The as-prepared Mn-CDs have UV emission with high quantum yield (83.2%). Because of the strong characteristic absorption of TNP at 356 nm, which has good spectral overlap with the emission peak of Mn-CDs, the fluorescence intensity of Mn-CDs at 360 nm is linearly quenched in the presence of TNP in the concentration range of 0.1–200 μM. The developing assay based on an inner filter effect (IFE) mechanism for detecting TNP is selective, convenient, and shows that the as-prepared Mn-CDs have application prospects for simple and specific analytical chemistry .
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Energy Technology
·
2018
·Vol. 7
·期 3
·1800694
·
IF 3.175
Chen Zhu,Jing-Pei Cao,Tao Xie,Xiao-Yan Zhao,Xin Cui,Zhen-Xing Guo,Wen-Zhong Shen,Jin Bai,Xian-Yong Wei
The influence of the type of support [activated carbon (AC), HZSM-5, and γ-Al 2 O 3 ] on the performance of Ni-based catalysts for the catalytic hydrogenolysis (CH) of benzyl phenyl ether (BPE) is investigated. The properties of an Ni-based catalyst are investigated using diverse characterization techniques. An Ni/AC catalyst exhibits the highest dispersion of Ni atoms by CO pulse. The kinetic studies show that the apparent activation energies ( E a ) for CH of BPE increase in the order E a (Ni/AC) < E a (Ni/γ-Al 2 O 3 ) < E a (Ni/HZSM-5), and the initial turnover frequencies follow the order of Ni/AC (64 mol mol Nisurf −1 h −1 ) > Ni/γ-Al 2 O 3 (58 mol mol Nisurf −1 h −1 ) > Ni/HZSM-5 (45 mol mol Nisurf −1 h −1 ). All these results prove that the CH activity of BPE is significantly affected by the type of support, and Ni/AC is the highest activity catalyst in CH of the C—O bond of BPE. Toluene and phenol are major products in CH of BPE at a relatively low hydrogen pressure and high temperature. Based on catalytic experiments, a reaction mechanism is proposed, which provides the theoretical basis for converting lignite into high-value organic molecules.
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