FUEL
·
2021
·
IF 6.609
Chengming Huang,Dingmei Han,Linjie Guan,Linhua Zhu,Yi Mei,Dedong He,Yun Zu
Propane dehydrogenation (PDH) is a prospective benign process for the production of propylene, but generally depends on high-price Pt and toxic Cr(VI) catalysts that often suffer from the rapid deactivation derived from metal sintering and severe coke deposition. To overcome these problems, the breakthroughs in an alternative catalyst design with efficient, low-cost and eco-friendly play a crucial role in successfully developing this process. Here, we facilely fabricate the bimetallic-site catalyst of Ni-Zn anchored in the zeolitic framework of silicalite-1 (depicted as NiZn-S-1) by employing ligand-protected strategy, which performs high temperature stability. Under comparable conditions, the NiZn-S-1 catalyst with high Ni/Zn molar ratio of 3:1 (named 0.2Ni0.06Zn-S-1) exhibits superior catalytic activity (initial propane conversion of 32.5 % and actual TOF propane of 28.5 min −1 ) with low deactivation rate (0.0778 h −1 ) and great propylene selectivity (>90%) after 30 h on stream. In particular, the catalytic performance on this catalyst almost keeps same as that of fresh catalyst after 4 successive oxidation–reduction cycles. Multiple characterizations further demonstrate that the enhancement of PDH performance ought to be attributed to the synergistic effect between bimetallic Ni-Zn sites, which favors the selective activation of C–H bond and propylene desorption to reduce the formation of coke species with high graphitization degree, boosting the improvement of catalyst stability. The design of novel bimetallic-sites catalyst can give a new idea on the development of alternative PDH catalysts with economical- and environment-friendly in the future.
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JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Jiacheng Xu,Bo Zhang,Yongkang Lu,Leigang Wang,Wanyi Tao,Xiao Teng,Wensheng Ning,Zekai Zhang
Preparation of PdO/SiO 2 @graphene oxide (GO) hybrid aerogels were carried out sol-gel method combined with atmospheric drying technology to study their adsorption performance for thiophenics and compared with PdO/SiO 2 . Scanning electron microscope (SEM), N 2 adsorption-desorption isotherms, X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and fourier transformation infrared spectroscopy (FT-IR) for samples were performed. The adsorption performance of PdO/SiO 2 @GO for thiophene were better than that of PdO/SiO 2 , attributed to that incorporation of GO increased the specific surface area and the Pd incorporation rate, where Pd 2+ ions acted as the π-complexation and sulfur-metal (S M) bond adsorption active centers, as well as GO adsorbed thiophene by the π-π stacking effect. The adsorption capacities of PdO/SiO 2 @GO-1.0 for thiophene (TH), benzothiophene (BT) and dibenzothiophene (DBT) were 8.89, 9.3 and 12.6 mg-S/g ads , respectively. The addition of GO in aerogels could improve the inhibition effect of toluene, cyclohexene and pyridine while decreased the inhibition effect of MTBE and H 2 O for the adsorption of thiophene, due to the π-π stacking effect and the hydrophobicity of GO, respectively. The adsorption process was spontaneous and exothermic, be well fitted by the apparent second-order kinetic model and dominated by chemical interaction. Pd/SiO 2 @GO-1.0 had a good solvent elution regeneration performance.
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Advanced Healthcare Materials
·
2021
·Vol. 10
·期 20
·2100938
·
IF 9.933
Gaizhen Kuang,Hongtong Lu,Shasha He,Hejian Xiong,Jie Yu,Qingfei Zhang,Yubin Huang
Stimuli-responsive nanosystems have been widely applied as effective modalities for drug/gene co-delivery in cancer treatment. However, precise spatiotemporal manipulations of drug/gene co-delivery, as well as multi-modality imaging-guided cancer therapy, still remain a daunting challenge. Here, multifunctional polyprodrug/siRNA loaded upconversion nanoparticles (UCNPs) are reported that combine computed tomography (CT), magnetic resonance (MR), and upconversion luminescence (UCL) tri-modality imaging and near-infrared (NIR) light-activated drug/gene on-demand delivery. The photoactivatable platinum(IV) (Pt(IV))-backbone polymers (PPt) and the siRNA targeting polo-like kinase 1 (Plk1) are loaded on the surface of polyethyleneimine (PEI)-coated UCNPs (PUCNP) to obtain the multifunctional polyprodrug/siRNA loaded UCNPs (PUCNP@Pt@siPlk1). The PUCNP@Pt@siPlk1 can be served as a “nanotransducer” to convert NIR light (980 nm) into local ultraviolet (UV) to visible light for the cleavage of photosensitive PPt, resulting in the simultaneous on-demand release of high toxic platinum(II) (Pt(II)) and siPlk1. Meanwhile, the PUCNP@Pt@siPlk1 has CT, T 1 -weighted MR, and UCL tri-modality imaging abilities. Based on these merits, PUCNP@Pt@siPlk1 displayed excellent synergistic therapeutic efficacy via image-guided and NIR light-activated platinum-based chemotherapy and RNA interfering in vitro and in vivo. Thus, this developed nanosystem with NIR light-controlled drug/gene delivery and multi-modality imaging abilities, will display great potential in combining chemotherapy and gene therapy.
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Polymer Chemistry
·
2021
·Vol. 12
·期 37
·5364-5376
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IF 5.582
Zhenghui Yang,Haiquan Guo,Chuanqing Kang,Lianxun Gao
Three novel dianhydride monomers involving amide groups were synthesized and further polymerized with various diamines to afford a series of colorless polyimides (cPI). The resultant cPI films present outstanding optical performance, exceedingly good dimensional stability at high temperature, great film ductility and solution-processability. In particular, chemically imidized AMDA/TFDB has an ultra-low coefficient of thermal expansion value of 5.2 ppm K−A, a relatively high Tg value of 333 °C and large elongation at break of 29%, resulting from its rigid-rod backbone and the formation of hydrogen bonding (–CO⋯NH–) between adjacent molecular chains. Concurrently, it exhibits a high optical transmittance of 87% at a wavelength of 550 nm, a small haze value of 0.71 and low yellow index of 4.29 by reason that the incorporation of bulky trifluoromethyl and cyclohexyl preclude the formation of a charge transfer complex effectively. The high overall performance of the amide-containing cPI films suggests its potential application in the field of flexible OLED displays.
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Foods
·
2021
·Vol. 10
·期 8
·1755
·
IF 4.35
Zhili Sheng,Junmei Liu,Bao Yang
Astragalus membranaceusis a functional food with multiple bioactivities. It presents differentiated health benefits due to origins. Polysaccharides (APS) are the leading bioactive macromolecules ofA. membranaceus, which are highly related to its health benefits. However, the effect of origin on the structural characteristics of APSs remains unclear. In this work, polysaccharides from four origins were isolated and identified by NMR. The results showed APSs of four origins had identical monosaccharide composition and glycosidic linkage. Rhamnogalacturonan II pectins and α-(1→4)-glucan were the dominant polysaccharides. However, the level of methyl ester in pectins varied to a large extent. The molecular weight profiles of APSs were also different. Inner Mongolia APS had the largest percentage of 20–40 kDa polysaccharides. Molecular weight and methyl ester level were two important parameters determining the difference of APSs from four origins. These results were helpful to recognize the origin-related quality ofA. membranaceus.Keywords:glycosidic linkage;monosaccharide composition;NMR;pectin
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ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Xiangyu Tang,Wei Huang,Yanjun Xie,Zefang Xiao,Haigang Wang,Daxin Liang,Jian Li,Yonggui Wang
The research of using bio-based nanocellulose to construct novel structures with tailored functions has attracted wide attention over the past few years. Unlike most of the studies starting with hydrophilic nanoscaled cellulose, undecenoate cellulose esters (UCEs) with different degrees of substitution (DSs) are used in this report to construct (super)hydrophobic coatings. UCE1.9 with a DS of 1.9 is composed of spherical nanoparticles (NPs), which have an average size of 112.8 nm. A crystalline cellulose core is present within UCE1.9 according to solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Self-assembly turned UCE1.9 NPs into microparticles (MPs) via a solvent-exchange process. The self-assembled UCE1.9 MPs dispersed in ethanol are well distributed on diverse substrates by spray coating to form superhydrophobic surfaces with micro/nanoscale hierarchical structures, which showed static water contact angles larger than 150° and sliding angles less than 10°. The prepared superhydrophobic surface holds its original superhydrophobicity when exposed to acidic or alkaline conditions and high temperatures. Moreover, UCE3 NPs constructed by UCE3 molecule chains with a DS of 3 tremendously enhanced the mechanical stability after addition into UCE1.9 MPs coatings, which was evaluated through sandpaper rubbing and tape peeling tests. Thus, these novel (super)hydrophobic coatings derived from sustainable cellulose are promising candidates for constructing biodegradable superhydrophobic materials.
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JOURNAL OF AOAC INTERNATIONAL
·
2021
·Vol. 105
·期 2
·576-586
·
IF 1.913
Guo Mei,Wu Zhicong,An Qi,Li Hengyang,Wang Lei,Zheng Yuguang,Guo Long,Zhang Dan
BackgroundEphedrae Herba (EH) is the terrestrial stem of Ephedra sinica Stapf, E. intermedia Schrenk et C. A. Mey., or E. equisetina Bge, which has been used as a diaphoretic, antiasthmatic, and diuretic. Honey-processed EH (HEH) is a widely used traditional Chinese medicine, and has a better effect of dispersing lung qi and relieving asthma and a lower effect of dispelling cold than raw EH (REH).ObjectiveTo understand the differences in volatile oils and primary metabolites between REH and honey-processed HEH, and to provide a reference for elucidating the mechanism behind the effect of this processing.MethodsA system data acquisition and mining strategy was designed to investigate the differences in volatiles and primary metabolites between the REH and HEH, based on GC–MS coupled with multivariate statistical analysis, including principal component analysis and orthogonal partial least squares discriminant analysis.ResultsOverall, 15 volatile oils and 14 primary metabolites were shown to be potential characteristic markers differentiating REH and HEH.ConclusionThe results may provide a scientific foundation for comprehensively revealing the honey-processing mechanism of EH.HighlightVolatile oils and primary metabolites were used to distinguish REH and HEH and elucidate the processing mechanism of EH for the first time.
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HIGH PERFORMANCE POLYMERS
·
2021
·
IF 2.161
Kai Ma,Hanzhou Jiang,Guofei Chen,Wei Wang,Yonggang Zhang
Several polyimides were prepared via two-step polycondensation from novel 2,5-furandicarboxylic acid–based diamine, 2,5-bis[4-(4-aminophenoxy)benzoyl]furan, with commercial dianhydrides. The chemical structures of the monomers and polymers were characterized by FT-IR and NMR in detail, respectively. The polyimides exhibited high performances with 5 wt% weight loss temperatures of over 410 oC, glass transition temperatures of over 214 oC, and tensile strengths and Young’s moduli of up to 130 MPa and 3.2 GPa, respectively. The thermal crosslinking mechanism was studied by FT-IR, Raman spectroscopy, and model reaction analysis, which showed the Diels–Alder reaction between the furan group and diphenylethylene group was the main reaction. The crosslinked polyimide films showed improved solvent resistance, and thermal and mechanical properties.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Yipeng Zheng,Zhennan Cao,Zheng Zhou,Gaodong Yang,Zhibing Zhang
A series of SO 3 -functional Brønsted acidic ionic liquids (SBAILs) were prepared to catalyze the N -formylation of aniline with DMF . The reaction conditions such as ionic liquid type, reaction temperature, catalyst loading and molar ratio of reactants were investigated. To the best of our knowledge, kinetic model for the N -formylation of aniline with DMF using SBAIL was firstly built and simulated. The studies on the reaction order of the reaction were evaluated by initial concentration method, and the kinetic parameters such as reaction rate constant and activation energy were proposed and used to explain the catalytic activities of the SBAILs catalysts. Accordingly, the recycling experiments showed that the SBAIL [Bsmim][HSO 4 ] can be easily recovered and reused with stable activity. Further, the temperature-controlled study emphasized that the ionic liquid was easy to be separated and environmentally friendly.
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CHEMOSPHERE
·
2021
·
IF 7.086
Shuhao Liu,Jinglong Han,Yangcheng Ding,Xiaoxu Gao,Haoyi Cheng,Hongcheng Wang,Chunshuang Liu,Aijie Wang
Pyridine and its derivatives are widely consumed and detected in the environment persistently, which can cause potential adverse impacts on environment and human health. Considering the fact that pyridine could absorb UV light at 254 nm to generate excited one, which could react with reductive radicals, promoting its structural changes, we proposed that one typical efficient advanced reduction process (ARP) which combines UV irradiation with sulfite could be used to eliminate pyridine quickly. Sulfite/UV process showed a higher pyridine removal rate with a pseudo-first-order reaction rate constant of 0.1439 min −1 , which was 3 times of that in UV irradiation and 1.3 times in UV/H 2 O 2 process. This was primarily due to reductive radicals (e aq – , H • and SO 3 •– ) produced by UV irradiation. The removal rate of pyridine was highest in slightly alkaline environment . And the presence of oxygen, as well as certain concentration of humid acid just showed slight inhibition, indicating the possibility of application in practical environment. A positive impact was observed with increasing sulfite dosage, but it was gradually inhabited when the dosage was over 5 mM. The present study may provide an alternative efficient technology for the degradation of pyridine ring-containing substances.
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NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 39
·15700-15705
·
IF 3.069
Yan Lei,Limei Yu,Maochang Shen,Shikang Luo,Zhanxian Gao
A series of ionic liquids (ILs) were synthesized and their Hammett acidities (H0) were determined using 4-nitroaniline as the indicator. The relationship among IL's structure, the acid strength, and the catalytic performance in the condensation reaction of 9-fluorenone with phenol was discussed. The effective H0 range of ionic liquids that can catalyse the condensation reaction was obtained. Moreover, the catalysis of the mercapto compound co-catalyst was also systematically studied. According to the analysis of how the structure of the sulfydryl co-catalyst affects the percent conversion of 9-fluorenone and the selectivity of BHPF, a mechanism for the reaction in the IL–thiol cooperative catalytic system was proposed. The present work gave a clear clue to design novel IL catalysts for the synthesis of BHPF.
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BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
·
2019
·Vol. 103
·期 5
·683-688
·
IF 1.65
Lu Tao,Zhou Zhigao,Zhang Qi,Zhang Zhenyan,Qian Haifeng
Extensive use of the fungicides azoxystrobin (AZ) and pyraclostrobin (PYR) can have negative effects on aquatic environments, but comprehensive studies on their effect on aquatic microbial communities are still lacking. We found that AZ and PYR could both inhibit the growth of Chlorella vulgaris , but PYR also inhibited Microcystis aeruginosa more strongly than did AZ. High-throughput sequencing analysis showed that AZ promoted the growth of Cyanobacteria in microcosms, and both PYR and AZ disturbed the ecological balance in the aquatic bacterial community and created distinct ecological risks. Our study suggests that the ecological risk of fungicides is complex, and fungicide use should be better managed to reduce potential risks to the environment.
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危险品化学品经营许可证（带存储）