APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 11
·e5932
·
IF 3.14
Yanming Jia,Junwen Wang,Kan Zhang,Chuanmin Ding
A highly shape-selective and relatively long-lifetime HZSM-5-based catalyst (Zn-2P/HZSM-5) was prepared by chemical modification with both ZnSiF 6 ·6H 2 O and H 3 PO 4 solution. The phosphoric acid modification could effectively modulate the Brønsted acid strength of the HZSM-5 catalyst, which promotes the oligomerization, alkylation, cyclization, and hydrogen transfer reactions. The introduction of Zn-Lewis acid sites significantly improved the dehydroaromatization of higher olefins. All of these were very beneficial for the generation of BTX (i.e. b enzene, t oluene, and x ylene) hydrocarbons in aromatization of methanol. The coke amount and the average rate of coke formation decreased over the Zn-2P/HZSM-5 catalysts, which may largely be ascribed to its lower strong acid sites and lower outer surface acidity. The catalytic performance of methanol aromatization showed that the Zn-2P/HZSM-5 catalyst exhibited the highest BTX selectivity of about 46.76% and the longest catalytic lifetime of about 498 h at T = 400 °C, P = 0.1 MPa, and weight hourly space velocity = 0.7 h −1 .
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TALANTA
·
2020
·
IF 5.339
Na An,Quan-Fei Zhu,Lei Yu,Yong-Ting Chen,Sheng-Li Chen,Yu-Qi Feng
In this study, a derivatization-assisted pseudo -multiple reaction monitoring with high CID voltage (HV- p -MRM) strategy was proposed for the analysis of brassinosteroids (BRs) by liquid chromatography-triple quadrupole mass spectrometry (LC-QqQ MS). The concept of the HV- p -MRM strategy was proposed on the basis of an assumption that the precursor ion of analyte is stable in collision cell and less prone to fragmentation at high CID voltage, while co-existing ions (impurity) of easy fragmentation can break down into smaller fragment ions. In such case, by increasing the CID voltage, the co-existing ions that are introduced due to the low resolution of the quadrupole 1 (Q1) can be filtered out by quadrupole 3 (Q3), while the stable precursor ion of analyte will pass through Q3, thereby that the signal-to-noise ratio (S/N) of the analysis can be improved. As a proof-of-concept study, BRs were derivatized with rhodamine B-boronic acid (RhB-BA) and then the derivatives were used to investigate their variations in MS signal, background noise, and S/N upon the CID voltage and MS scanning resolution. The results showed that S/N of these derivatives can be improved in HV- p -MRM mode. To further demonstrate the feasibility of HV- p -MRM strategy, a RhB-BA derivatization assisted LC-HV- p -MRM-MS method was developed for the analysis of BRs. Using this method, rapid and sensitive determination of BRs in different organs of rape flower was achieved. It can be expected that HV- p -MRM may be suitable for the analytes that are stable or can be converted into compounds of high stability in collision cell at high CID voltage.
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2020
·Vol. 298
·期 6
·629-636
·
IF 1.536
Yang Xu,Li Wenbo,Sun Zhaojie,Yang Chunhui,Tang Dongyan
In this work, pH/temperature dual-sensitive polymers of P(NVCL-co-MAA) with the increased low critical solution temperature (LCST) values of about 37 °C that differed from that of ~ 32 °C of pure poly(N-vinyl caprolactam) (PNVCL) were synthesized via radical polymerization. Then the nanofibers of P(NVCL-co-MAA) and its cospinned nanofibers with nifedipine (NIF) as drug model were fabricated by electrospinning method. Structures and the interactions within the components were detected by FT-IR, NMR, and XPS methods. The dual-responsive properties and the controlling release of the drug were investigated by water contact angle tests and in vitro drug release tested by UV-vis spectrophotometer. SEM was conducted to demonstrate the morphology of the nanofibers and the obvious improved stabilized morphology of the modified system within the aqueous media. The maintained morphology within the media and the obvious elongated releasing period of over 150 min at 37 °C and with pH of 1.99 both proved the promising prospects of the fabricated nanofibers as excellent carrier in drug delivery system.
Graphical abstract
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INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Haonan Liu,Hongping Wu,Hongwei Yu,Zhanggui Hu,Jiyang Wang,Yicheng Wu
Mo(VI)-containing phosphates are widely used in catalyses, ion batteries, and nonlinear optical (NLO) crystals. However, few strategies can effectively guide the syntheses of the Mo(VI)-containing phosphates. In this paper, three new Mo(VI)-containing phosphates, Cs3Mo12PO40, LiK(MoPO6)2, and Sr(MoPO6)2, with different dimensions have been successfully synthesized by adjusting the Mo/P ratios. Interestingly, Cs3Mo12PO40 is a classic Keggin-type polyoxometalate composed of zero-dimensional (0D) [Mo12PO40]3– clusters, whereas LiK(MoPO6)2 and Sr(MoPO6)2 have three-dimensional (3D) [MoO2O4P]∞ frameworks consisting of MoO6 octahedra and PO4 tetrahedra in a 1/1 ratio. Detailed structural comparisons of Mo(VI)-containig phosphates indicate that the Mo/P ratios have a significant effect on the structural dimensions. Further, the optical properties and thermal stabilities of Cs3Mo12PO40, LiK(MoPO6)2, and Sr(MoPO6)2 are also determined.
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2020
·
IF 3.333
Xin Hu,Ning Li,Tingting Heng,Liang Fang,Chunhua Lu
An efficient graft modification strategy was developed based on photo-induced organocatalyzed atom transfer radical polymerization (O-ATRP) for the functionalization of poly(vinylidene fluoride) (PVDF) based copolymer . P -anisaldehyde was served as an organic photoredox catalyst to mediated O-ATRP of methyl methacrylate (MMA) and glycidyl methacrylate (GMA) in the presence of poly(vinylidene fluoride- co -chlorotrifluoroethylene) (P(VDF- co -CTFE)) as the macroinitiator under UV irradiation . Excellent temporal control and low catalyst concentration was achieved. Chain extension confirmed the chlorine atom attached to the graft polymer chain end. Metal-free P(VDF- co -CTFE)- g -PMMA and P(VDF- co -CTFE)- g -PGMA with varied graft contents were obtained, which would find potential applications in dielectric materials .
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Nanoscale
·
2020
·Vol. 12
·期 27
·14863-14869
·
IF 6.895
Shuli Yin,You Xu,Songliang Liu,Hongjie Yu,Ziqiang Wang,Xiaonian Li,Liang Wang,Hongjing Wang
The development of doped noble metal catalysts with nonmetal elements to improve the catalytic performance toward the oxygen reduction reaction (ORR) is significant for proton exchange membrane fuel cell technology. Here, we report a one-pot for dual-nonmetal-doping strategy for the synthesis of S and P-co-doped mesoporous PtPd nanocages (PtPdSP mNCs) by using pre-synthesized mesoporous PtPd nanocages (PtPd mNCs) as the precursor and triphenylphosphine sulphide as both S and P sources. Benefitting from the combined advantages of metal–nonmetal incorporation, hollow cavity and surface porosity, the resultant quaternary PtPdSP mNCs exhibit outstanding ORR activity and long-term stability. This research work provides a good strategy for the doping of two or more selected nonmetallic elements into metallic nanocrystals with a controllable structure and composition.
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JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
·
2020
·Vol. 97
·期 3
·289-300
·
IF 1.659
Hardy Z. Castada,Zhaoyu Sun,Sheryl A. Barringer,Xuesong Huang
p -Hydroxybenzoic acid (PHBA) plays a significant role in sustaining the oxidative stability of macadamia nut oil (MNO). However, PHBA undergoes thermal decarboxylation and loses its bioactive antioxidant properties. In this study, we determine PHBA degradation kinetics in oils at various heating temperatures, which provides fundamental understanding of PHBA thermal degradation in oils and oil quality changes during high-temperature processing. PHBA degradation kinetics in MNO, olive oil, and corn oil were evaluated at temperatures typical for cooking and frying. PBHA headspace concentration was measured using selected ion flow tube mass spectrometry. PHBA decarboxylation followed a zero-order reaction, where degradation could be affected by factors such as the type of oil matrix having different FA compositions, antioxidants, and component interactions. PHBA degradation activation energies ( E a ) showed that PHBA was more stable against thermal decarboxylation in MNO (85 kJ mol –1 ) than in olive oil (40 kJ mol −1 ) or corn oil (22 kJ mol −1 ). The higher enthalpy ( ) of decarboxylation in MNO (82 kJ mol −1 ) indicates that PHBA is more inhibited from decomposition than olive oil (37 kJ mol −1 ) or corn oil (19 kJ mol −1 ). Moreover, the negative entropy values ( ) of PHBA degradation from MNO (−192 J mol −1 K −1 ), olive oil (−277 J mol −1 K −1 ), and corn oil (−325 J mol −1 K −1 ) indicates that these oils impart some inhibitory properties against PHBA thermal decarboxylation.
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Small
·
2021
·Vol. 17
·期 37
·2102272
·
IF 13.281
Xi Guo,Biao Zhao,Kunxiang Xu,Shaomin Yang,Zhike Liu,Yu Han,Jie Xu,Dongfang Xu,Zhanao Tan,Shengzhong (Frank) Liu
Interface modification to minimize charge recombination and trapping for efficient charge transport is crucial for the performance of perovskite solar cells (PSCs). Herein, functionalized p-type blue carbon dots (B-CDs) are ventured as an interface passivation layer to enhance the efficiency and long-term stability of all-inorganic CsPbI 2 Br PSCs. It is found that first the blue carbon dots with abundant N H, C N, C O, and CO functional groups effectively passivate defects by reacting with I − and Pb 2+ ions in the perovskite through hydrogen and coordinative bonds. Second, the p-type B-CDs modifiers form a P–N junction with the n-type perovskite to provide efficient pathways for hole transfer and electron blocking. Third, the B-CDs increase the hydrophobicity of the perovskite film to improve the stability of CsPbI 2 Br PSCs. With the above advantages, the CsPbI 2 Br PSC with B-CDs modification shows an efficiency as high as 16.76%, one of the highest for its type. In addition, the modification renders significant improvement of air and light stability, with 95.33% of the initial PCE retained after storage in the ambient environment for 1000 h. This work demonstrates the great potential of B-CDs application in perovskite-based optoelectronic devices.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Hongxia Liu,Hui Mei,Shiping Li,Longkai Pan,Zhipeng Jin,Gangqiang Zhu,Laifei Cheng,Litong Zhang
Bismuth titanate (Bi 12 TiO 20 ) with unique sillenite structure has been shown to be an excellent photocatalyst for environmental remediation. However, the narrow light-responsive range and rapid recombination of photoinduced electrons-holes limit the photocatalytic performance of Bi 12 TiO 20 . To overcome the limitations, a practical and feasible way is to fabricate heterojunctions by combining Bi 12 TiO 20 with suitable photocatalysts. Here, using a facile chemical precipitation method, a novel and hierarchical core–shell structure of n-Bi 12 TiO 20 @p-BiOI (BTO@BiOI) heterojunction was rationally designed and synthesized by loading BiOI nanosheets on BTO nanofibers. The constructed BTO@BiOI composites exhibited significant charge transfer ability due to the synergistic effects of the built-in electric field between BTO and BiOI as well as close interfacial contacts. In addition, the narrow bandgap characteristics of the BiOI led to wide light absorption ranges. Therefore, the BTO@BiOI heterojunction exhibited an improved photocatalytic performance under visible light irradiation. The NO removal efficiency of optimal BTO@BiOI was 45.7%, which was significantly higher compared to that of pure BTO (3.6%) or BiOI (23.1%). Moreover, the cycling experiment revealed that BTO@BiOI composite has a good stability and reusability. The possible mechanism of photocatalytic NO oxidation over BTO@BiOI was investigated in detail.
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ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Zhenwei Miao,Dongpeng Yan,Teng Zhang,Fan Yang,Shuangkun Zhang,Wei Liu,Zhanpeng Wu
Modification by intumescent flame retardants is an effective way to impart antiflame properties to fabric materials. Polyphosphazene elastomers contain all three elements required by intumescent flame retardants: an acid source, a gas source, and a carbon source, making them all-in-one integrated intumescent flame retardants. In this work, halogen-free poly(dimethoxy)phosphazene (PDMP) loaded with 29.0 wt % phosphorus and 13.1 wt % nitrogen is shown to be an ideal flame retardant for fabric materials. For the first time, transparent and elastic PDMP was applied as an intumescent flame retardant for cotton fabric. The PDMP-coated cotton shows remarkable high-efficiency flame-retardant properties: (1) a self-extinguishing property during the vertical flame test is obtained when the add-on level reaches 5.3 wt %, with a lower smoke release character; (2) the limiting oxygen index (LOI) values of coated cotton are improved with increasing add-on level, and the thickness of the coating is measured to be at the nanolevel, 2540 nm when 10.9 wt % PDMP is coated. The coated cotton shows enhanced carbonization ability at lower temperatures, which is the key to imparting flame-retardant properties to cotton, and the PDMP-coated cotton shows remarkably lower peak heat release rate and total heat release compared to the control cotton during combustion. The durability of modified cotton was tested after 50 laundering cycles, which showed that the coating maintains 80% of its initial mass, and the after-laundering sample preserves the characteristics of self-extinguishing and a high LOI. Thus, the PDMP nanocoating-modified flame-retardant cotton fabric is sufficiently durable for practical application.
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ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Xiangyu Ma,Kun Qian,Onome Ejeromedoghene,Martha Kandawa-Schulz,Wei Song,Yihong Wang
In this work, we report AuNPs-decorated pyrolyzed Co-BDC nanosheets (p-Co-BDC/AuNPs) as high-performance electrocatalyst for developing an electrochemical platform. p-Co-BDC/AuNPs as a new electrocatalyst showed superior electrocatalytic activity towards the electrochemical oxidation of methylene blue (MB). Besides, magnetic p-Co-BDC/AuNPs can be well immobilized on the magnetic glassy carbon electrode without further assistance. The oxidation of MB can be reduced by ascorbic acid . Inspired by this phenomenon, an electrochemical biosensor was constructed based on multiple signal amplification for the diagnosis of miRNAs . Firstly, p-Co-BDC/AuNPs enhanced the electrochemical oxidation of MB. Then, strand displacement amplification reaction can form lots of double helix structure DNA to embed more MB molecules. Finally, ascorbic acid in the electrolyte was utilized to reduce the oxidation of MB and improve the electrochemical signal of MB electro-oxidation. The linear detection range for the detection of miRNAs is 100 aM to 10 nM, and the limit of detection is 86 aM. Furthermore, the constructed biosensor also displayed satisfactory selectivity , good reproducibility, and excellent recovery in the detection of real samples. We are convinced that our proposed multiple signal amplification strategy will provide more promising methods for the diagnosis of cancer.
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MATERIALS LETTERS
·
2021
·
IF 3.423
Zhiyuan Zhou,Jiamin Zhang,Xiyue Duan,Weiming Lin,Yang Yi,Wenjian Weng,Kui Cheng,Zuobing Chen
Graphene (Gr)/poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) composite films were annealed by the photothermal effect that produced between near-infrared laser and graphene. Raman spectra, X-ray Diffraction (XRD), Fourier-Transformed Infrared Spectroscopy (FTIR), Differential scanning calorimetry (DSC) are used to characterize the crystalline state of Gr/P(VDF-TrFE) films. Further, piezoelectric coefficient d 33 were to test polarization performance. Finally, the Bovine serum albumin (BSA) adsorption shows that annealing and polarization of Gr/P(VDF-TrFE) films are important for protein adsorption.
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危险品化学品经营许可证（带存储）