ENERGY & FUELS
·
2020
·
IF 3.421
Suya Yin,Taishun Yang,Yuan Xue,Maiying Xie,Fengfei Chen,Hualin Lin,Bin Dai,Feng Gao,Sheng Han
High-efficiency pour point depressants (PPDs) for diesel fuel were obtained using a series of tetradecyl methacrylate-N-α-methacrylamide copolymers (C14MC-NMLR) with different molar ratios synthesized through radical polymerization of tetradecyl methacrylate (C14MC) and various forms of N-α-methacrylamide (NMLR, R = -phenyl, -naphthyl, -cyclohexyl, -14a, -16a, -18a). The copolymers were characterized by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, and thermogravimetric analysis. Results showed that diesel treated with C14MC-NML-phenyl (9:1) and C14MC-NML-14a (6:1) presented better cold flow properties at 2000 ppm, and the reductions in cold filter-plug point (ΔCFPP) and solid point (ΔSP) were (23 and 10 °C) and (22 and 11 °C) at 2000 ppm, respectively. The depressive effects further improved after compounding. When they were combined at a 1:4 mass ratio, PPDC-6 presented the best depressive effects, and the ΔCFPP and ΔSP reached 25 and 11 °C at 1000 ppm dosage and 28 and 15 °C at 2000 ppm dosage, respectively. Additionally, the crystallization behavior and crystal morphology of each treated diesel were explored.
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NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 7
·2890-2896
·
IF 3.288
Yinhui Yang,Meiling Qi,Jinliang Wang
Here we report a novel hexaphenylbenzene (HPB)-based material functionalized with six tetraphenylethylene units (BPT) with unique conformation-driven selectivity for gas chromatographic (GC) separations. It is composed of a neat aromatic hydrocarbon with a rigid propeller-like conformation. As a result, the BPT capillary column exhibited high column efficiency of 5340 plates per m and high-resolution capability for aromatic to aliphatic isomers with excellent intra-day and inter-day repeatability and between-column reproducibility. The results demonstrate the unique conformation-driven selectivity of the HPB-based stationary phase, which is rarely reported for chromatography. Moreover, its application in the determination of isomer impurities in commercial products proved its good potential for practical GC analysis. This work presents a new perspective for developing selective stationary phases by engineering their structures.
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BMC Chemistry
·
2020
·Vol. 14
·期 1
·1-7
·
IF 0
Ye Changwen,He Chen,Zhang Bowen,Wang Lixuan,Wang Lufeng
Zizania latifolia is easily lignified after harvesting, leading to the degradation of food quality and commercial value. Thus, this study evaluated the effect of radio frequency (RF) treatments on lignification inhibition of Zizania latifolia . The results showed that the lignin content of Zizania latifolia treated with RF decreased significantly compared with the control group. At the 7th day of storage, the phenylalanine ammonia lyase activity of the 90 W RF treatment group decreased by 52.9% compared with the initial value. The activities of peroxidase and polyphenol oxidase in the stems of Zizania latifolia were significantly ( p < 0.05) decreased after RF treatments. Besides, a decrease in conversion rate of O 2 − and H 2 O 2 to downstream products was observed, indicating that the related invertases were inhibited by RF treatment. All of these showed that RF treatments contribute to inhibit or delay the lignification of Zizania latifolia , providing a better taste and quality for products.
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JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jiaping Xu,Kai Zhang,Lei Wang,Yiming Yao,Hongwen Sun
Sorption/desorption of two organic compounds (OCs), phenanthrene (PHE), and 1-nitronaphthalene (1-Nnap) on three polar and one nonpolar polypropylene (PP) microplastics (MPs) and earthworm bioaccumulation of MP associated PHE were systematically studied. Poly-butylene succinate (PBS) with the lowest glass transition temperature ( T g ) showed the highest sorption toward PHE and 1-Nnap ( K d : 25,639 ± 276 and 1673 ± 28.8 L kg −1 , respectively), while polylactic acid (PLA) with the highest T g showed the least sorption (182 ± 5 and near 0), confirming that hydrophobic partition was the main driving force of sorption. However, polar interactions also contributed to the preferential sorption of 1-Nnap on polar poly-hydroxyalkanoates (PHA). Moreover, small particle size favored the sorption of MPs and simulated weathering enhanced sorption on MPs with medium/high T g. As for desorption, slight hysteresis was observed in most cases with near-zero hysteresis index (HI), and PHE generally had higher HI than 1-Nnap. The simulated digestive solution could further promote the desorption of PHE. The PHE concentrations in earthworms with the presence of 5% PBS or PP MPs in soil were 1.50–2.35 or 1.59–1.75 times that of the control without MPs; and PBS MPs with the smallest particle size showed the greatest enhancement. The results of this study confirmed that polar MPs could strongly but reversibly sorb both polar and nonpolar OCs and hence promote the bioaccumulation of OCs to soil organisms.
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CRYSTAL GROWTH & DESIGN
·
2019
·
IF 4.153
Yuting Liu,Mingtao Zhang,Danrui Xu,Sean Parkin,Tonglei Li,Conggang Li,Zhaoyong Yang,Faquan Yu,Sihui Long
To probe the effect of substituent size and isomerization on the polymorphism of fenamic acid (FA) derivatives, we synthesized two FA analogues, namely, 2-(naphthalen-1-ylamino)-benzoic acid and 2-(naphthalen-2-ylamino)-benzoic acid (NBAs), and investigated their polymorphism. Contrary to the lack of polymorphism in FA, we discovered two crystal forms (1-I, 1-II, 2-I, and 2-II) for each of the two compounds. We characterized the two polymorphic systems with single-crystal X-ray diffraction, powder X-ray diffraction, and infrared and Raman spectroscopy, and observed certain structural similarities between 1-I and 2-I. The phase behavior of these two systems were studied with differential scanning calorimetry. Computational studies such as the search for stable conformers, lattice-energy calculations, and Hirshfeld surface analysis were performed to shed light on the polymorphism, relative stability of the forms in each system, and contribution of intermolecular interactions to the overall stability of the systems. The study confirmed the effect of substituent size on the polymorphism of the compounds.
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Jie-Ping Fan,Jun-Jing Luo,Xue-Hong Zhang,Bing Zhen,Chun-Yi Dong,Yan-Chen Li,Jian Shen,Yu-Tong Cheng,Hui-Ping Chen
In this work, a novel electrospun β-cyclodextrin (β-CD)/chitosan (CS)/polyvinyl alcohol (PVA) nanofiber membrane was prepared to simultaneously and rapidly remove organic and heavy metal micropollutants. The preparation conditions were optimized by multi-objective response surface methodology, and obtained as follows: 100% of the amount of β-CD (relative to PVA), 49.49% of the amount of CS (relative to PVA), 20 cm of the distance between the needle tip and the collector drum, 0.23 mL h −1 of the flow rate of the spinning solution, and 8.72% of the amount of PVA (relative to water). The characterization by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) showed a well cross-linked β-CD/CS/PVA nanofiber membrane was formed. In the static and dynamic adsorption experiments, the results demonstrated that the β-CD/CS/PVA nanofiber membrane was highly efficient in simultaneous and rapid removal of organic and heavy metal micropollutants in water treatment process.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Zhen Li,Mei Li,Cong Wang,Xinhui Zhou,Jianfeng Li,Daoliang Li
Based on modified diazo reaction, a novel surface-enhanced resonance Raman scattering (SERRS) method employed for ultrasensitive, highly selective, and ultra-trace determination of nitrite in aquaculture water was demonstrated. The azo dyes, which are formed by 4-aminothiophenol, nitrite, and N-(1-naphthyl) ethylenediamine dihydrochloride in acid conditions, can exhibit high SERS signal on Ag nanoparticles. Subsequently, the concentration of nitrite can be determined from the intensity of SERRS of derivative. Under optimal conditions, a linear relationship between Raman intensity and the nitrite concentration was found in the range of 0.1–15.0 μmol L −1 with a good correlation coefficient (R 2 = 0.9921) at 1380 cm −1 , and the limit of detection can reach as low as 16.4, 24.0, 9.0, and 24.6 nmol L −1 at 1138, 1332, 1380 and 1418 cm −1 , respectively. Additionally, the results indicate that the present method can be applied to detect nitrite in real aquaculture water samples without influence of interfering ions. This study provides a feasible method for accurate, trace, and fast field detection of nitrite in aquaculture water with strong potential to be used for on-line and on-site optical sensors of nitrites.
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ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Chenyue Zhan,Jiatian Cheng,Bowen Li,Shuailing Huang,Fang Zeng,Shuizhu Wu
Melanoma is a type of highly malignant and metastatic skin cancer, and early detection of melanoma by analyzing the level of its biomarker may decrease the likelihood of mortality. In this study, a fluorescent probe called NBR-AP for detecting tyrosinase (a biomarker of melanoma) has been created by incorporating a hydroxyphenylurea group (as a substrate for the enzyme) onto a fluorescent dye phenoxazine derivative (as an activatable signal reporter). This probe can be activated to generate fluorescence through a tyrosinase-mediated oxidation followed by hydrolysis of the urea linkage. The probe is able to detect the endogenous tyrosinase level in live cells and in zebrafish sensitively and selectively. Moreover, by imaging the tyrosinase activity, NBR-AP has been successfully applied to diagnose the melanoma and its metastasis in xenogeneic mouse models established via subcutaneous injection of B16F10 cells.
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Materials Research Express
·
2018
·Vol. 6
·期 1
·015053
·
IF 1.151
L Z Pei,Y Ma,F L Qiu,F F Lin,C G Fan,X Z Ling
Polynaphthylamine/graphene composites have been synthesized by an in situ polymerization of the naphthylamine monomers and graphene. The polynaphthylamine/graphene composites were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Raman spectrum and Fourier transform infrared spectrum (FTIR). The analytical results show that the polynaphthylamine/graphene composites possess hexagonal graphite-2H phase and are composed of irregular polynaphthylamine particles and graphene nanosheets with the wrinkles and folds. The bare glassy carbon electrode was modified with the polynaphthylamine/graphene composites for the detection of benzoic acid. The polynaphthylamine/graphene composites modified glassy carbon electrode exhibits an irreversible oxidation cyclic voltammogram (CV) peak located at +0.29 V. The significant enhancement in the current response is observed as the increase of the scan rate, benzoic acid concentration and decrease of the pH value of the electrolyte. The current response of the CV peak of the benzoic acid exhibits a linear relationship with the benzoic acid concentration ranging from 0.001–2 mM. The detection limit is 0.34 μM. The polynaphthylamine/graphene composites modified glassy carbon electrode reveals great promising for the determination of benzoic acid.
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JOURNAL OF HAZARDOUS MATERIALS
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2018
·
IF 6.434
Lingshuai Kong,Guodong Fang,Ya Kong,Meng Xie,Vinothkumar Natarajan,Dongmei Zhou,Jinhua Zhan
Wastewater systems contain a large number of compounds, such as anthropogenic aromatic pollutants and natural organic matter (NOM), and usually have pH higher than 4. Fenton-like reaction is the most widespread method for removal of organic pollutants, but their reactivity with H 2 O 2 may be inhibited by NOM due to the competition of hydroxyl radicals and chelating agents. In this work, Cu 2 O@β-cyclodextrin was developed to achieve the collaboration between molecular recognition and Fenton-like catalysis to destruct aromatic pollutants at neutral pH. In Cu 2 O@β-CD, covalent Cu O C bond was topotaxially converted from CuCl assisted by β-CD at room temperature. Covalently linked β-CD could keep humic acid from interfering catalytic performance of Cu 2 O surfaces and inhibit the leaching of copper. A higher catalytic ability was observed for Cu 2 O@β-CD with rate constant 0.0331 min −1 than Cu 2 O (0.0064 min −1 ) at neutral pH. A mechanism of synergistic catalysis was proposed on the basis of Cu + , β-CD and phenoxo-Cu 2+ complexes in the Cu 2 O@β-CD/BPA/H 2 O 2 system. The strategy of coupling molecular recognition into Fenton-like reaction provides an efficient and promising approach to the destruction of aromatic pollutants at neutral pH.
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Analytical Methods
·
2018
·Vol. 10
·期 29
·3637-3644
·
IF 2.073
Juanjuan Xie,Bo Zhou,Tiandong Zhang,Xiaoying Zeng,Mochou Yang,Wanwan Wang,Jun Yang
A new method of molecularly imprinted polymer solid-phase extraction (MISPE) coupled with gas chromatography-mass spectrometry was developed for the determination of nicotine in the zero-level refill liquids of electronic cigarettes. The surface molecularly imprinted polymers (SMIP) were synthesized on the surface of vinyl-SiO2 nanospheres using nicotine as a template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker in toluene solution. The prepared SMIPs showed high adsorption capacity (247.0 μmol g−1), excellent imprinting factor (4.40), and high selectivity toward nicotine with selectivity coefficients higher than 2.9. Finally, the SMIPs were successfully utilized as solid-phase extraction (SPE) sorbents for the extraction of nicotine in the zero-level refill liquids of electronic cigarettes (ECs). The newly established method showed good linearity in the range of 2.00–40.00 μg mL−1. The limit of detection (LOD, S/N = 3) was 0.50 μg mL−1, the limit of quantification (LOQ, S/N = 10) was 1.66 μg mL−1, and the average recoveries range from 76.2% to 83.9% with relative standard deviations lower than 6.4% (n = 6). These results indicated that a feasible and reliable method was developed for the determination of nicotine in zero-level refill liquids of electronic cigarettes, which could provide an alternative solution for the quality control of electronic cigarette products.
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Polymers
·
2018
·Vol. 10
·期 12
·1329
·
IF 2.935
Lingyu Liu,Xudong Zhu,Yanbo Zeng,Hailong Wang,Yixia Lu,Jian Zhang,Zhengzhi Yin,Zhidong Chen,Yiwen Yang,Lei Li
In this paper, we report a new composite of reduced graphene oxide/Fe3O4-ionic liquid based molecularly imprinted polymer (RGO/Fe3O4-IL-MIP) fabricated for diphenylamine (DPA) detection. RGO/Fe3O4-IL-MIP was prepared with RGO/Fe3O4as supporter, ionic liquid 1-vinyl-3-butylimidazolium hexafluorophosphate ([VC4mim][PF6]) as functional monomer, ionic liquid 1,4-butanediyl-3,3’-bis-l-vinylimidazolium dihexafluorophosphate ([V2C4(mim)2][(PF6)2]) as cross-linker, and diphenylamine (DPA) as template molecule. Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy, and vibrating sample magnetometer were employed to characterize the RGO/Fe3O4-IL-MIP composite. RGO/Fe3O4-IL-MIP was then drop-cast onto a glassy carbon electrode to construct an electrochemical sensor for DPA. The differential pulse voltammetry (DPV) peak current response for 20 μM DPA of RGO/Fe3O4-IL-MIP modified glassy carbon electrode (GCE) was 3.24 and 1.68 times that of RGO/Fe3O4-IL-NIP and RGO/Fe3O4-EGDMA-MIP modified GCEs, respectively, indicating the advantage of RGO/Fe3O4-IL-MIP based on ionic liquid (IL) as a cross-linker. The RGO/Fe3O4-IL-MIP sensor demonstrated good recognition for DPA. Under the optimized conditions, the RGO/Fe3O4-IL-MIP sensor exhibited a DPA detection limit of 0.05 μM (S/N = 3) with a linear range of 0.1–30 μM. Moreover, the new RGO/Fe3O4-IL-MIP based sensor detected DPA in real samples with satisfactory results.Keywords:reduced graphene oxide;Fe3O4;molecularly imprinted polymer;ionic liquid cross-linker;electrochemical sensor;diphenylamine
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