RSC Advances
·
2019
·Vol. 9
·期 19
·10569-10577
·
IF 3.049
Jianru Ma,Wenzhi Li,Shengnan Guan,Qiying Liu,Qingqing Li,Chaofeng Zhu,Tao Yang,Ajibola Temitope Ogunbiyi,Longlong Ma
Sulfonated graphene (SG) was prepared and employed to convert corn stalk and xylose into furfural. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize SG. The effects of reaction time, temperature, substrate loading, catalyst dosage and solvents on the reaction were researched and optimized. SG exhibited high catalytic activity in the conversion of xylose and corn stalk to furfural. A fairly high furfural yield of 96% was achieved at 150 °C from xylose and a 71.9% furfural yield was obtained when using a 10.7 ratio (mass ratio: xylose to SG) at 140 °C. While a 48% furfural yield was obtained from corn stalk (based on the starting combined moles of xylan and glucan in corn stalk; yield was >100%, if based on only xylan) using a substrate loading (corn stalk to catalyst mass ratio) of 2.14 and a 19% 5-hydroxymethylfurfural (5-HMF) yield was obtained. What's more, a 43.9% yield of furfural was obtained in only 20 min. In addition, the reusability of SG was also investigated and shown to have good stability for xylose dehydration.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2019
·Vol. 166
·期 8
·D276
·
IF 3.12
Yu-Ke Zhong,Kui Liu,Ya-Lan Liu,Yue-Xiang Lu,Tai-Qi Yin,Lin Wang,Zhi-fang Chai,Wei-Qun Shi
Uranium-molybdenum (U-Mo) alloys especially the γ-U-Mo phase, with excellent irradiation performance at high temperatures, have been extensively studied as low-enriched-uranium candidate fuels for strengthening nuclear security and nonproliferation worldwide. Herein, we provide a facile method to successfully prepare the γ-U-Mo alloys (U-10Mo and U-8Mo) directly from oxide precursors via electro-reduction by constant cell voltage electrolysis in LiCl molten salt at 986 K. The reduction mechanism was elucidated through cyclic voltammetry using the metallic cavity electrode (MCE) combined with XRD, SEM and EDS characterizations toward the electrolysis products under different conditions. It was found that the reduction of mixed MoO3-UO2 oxides may take place in three steps. Firstly, MoO3 was reduced to Li4Mo5O12, and then Li4Mo5O12 was converted into Mo. Finally, the U-Mo alloys were formed due to the underpotential deposition of U on the pre-formed Mo. In addition, the effects of cell voltage, sintering temperature and mixture composition on the electrochemical reduction were investigated. The results found that the reduction rate increased with the augmentation of applied potential and the decrease of sintering temperature. Moreover, the favorable composition of the mixed precursor varied from 24 at% to 21at%. The reduction conversion rate was determined to be 93.7% by ICP and TGA.
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Molecular Medicine Reports
·
2019
·Vol. 19
·期 6
·5417-5423
·
IF 1.851
Zhimin Wang,Fang Li,Yuan Quan,Junye Shen
Hepatocellular carcinoma (HCC) has become a global public health problem. Therefore, the development of novel and effective therapeutic agents for the treatment of HCC is considered an emergency. Avicularin, a bio‑active flavonoid from plants, has been reported to exhibit diverse pharmacological properties. The aim of the present study was to investigate the role of avicularin in HCC and the underlying mechanism of action. Huh7 cells were treated with avicularin in a concentration‑dependent manner, and the cell proliferation was examined using a 3‑(4, 5‑dimethylthiazol‑2‑yl)‑2, 5‑diphenyltetrazolium bromide assay kit. The cell migration and invasion abilities were detected using wounding‑healing assays and Transwell assays. Flow cytometric analysis was performed to investigate the cell cycle distribution and cell apoptosis. The activity of nuclear factor (NF)‑κB (p65), cyclooxygenase‑2 (COX‑2) and peroxisome proliferator‑activated receptor γ (PPAR‑γ) were measured by reverse transcription‑quantitative polymerase chain reaction and western blot analyses, respectively. The results indicated that avicularin treatment markedly decreased cell proliferation concentration‑dependently in HCC, and inhibited cell migration and invasion in Huh7 cells. It was also found that the treatment of avicularin markedly inhibited the G0/G1‑phase cells and decreased the accumulation of S‑phase cells in the cell cycle and induced cell apoptosis. In addition, it was confirmed that the anticancer efficacy of avicularin in HCC was dependent on the regulation of NF‑κB (p65), COX‑2 and PPAR‑γ activities. In conclusion, the findings suggested that avicularin serves an antineoplastic role in HCC and may provide a potential therapeutic strategy for the treatment of HCC.
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高影响因子
E-POLYMERS
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2019
·Vol. 19
·期 1
·323-329
·
IF 1.491
XianRong Shen,DengZhou Xia,YiXin Xiang,JianGang Gao
In this paper, γ-valerolactone (GVL), a bio-based polar solvent, was applied as green solvent for iron(III)-catalyzed AGET ATRP without any external ligand. GVL is a fully degradable, non-toxic green solvent and has complex ability to iron halide complexes through –OCO- group. GVL as the solvent and the ligand for AGET ATRP of MMA in a controlled manner, as proved by kinetic study, the low PDI values and the increase in polymer molecular weight versus monomer conversion. Chain re-initiation experiments and 1 HNMR characterization were conducted to further confirm the living feature. Graphical
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Li You,Jianxin Cao,Fei Liu
A novel microchannel synthesis route for continuous synthesis of nanosized copper iodide (γ-CuI) using hydrated hydrazine as reducing agent was proposed. We continuously produced γ-CuI spherical nanoparticles in 99% yield and grain size of ca. 44–100 nm. Furthermore, the utilization of hydrated hydrazine was essential in precluding powder plugging the microchannel by self-generated N2. The microreaction process conditions, such as residence time, pH value, temperature, and reactant concentration, had great impact on the crystal phase and grain size. The optical properties analysis showed that red-shift in band age and emission intensity of photoluminescence spectra at 428 nm decreased with decreasing grain size. Moreover, the nanosized spherical γ-CuI exhibits enhanced photocatalytic performance in the photodegradation of methylene blue and methyl orange.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
·
IF 8.355
Feifei Wang,Xiaolin Yu,Maofa Ge,Sujun Wu
A series of TiO 2 and γ-Fe 2 O 3 co-doped graphene oxide (GO) nanosheets ( x TiO 2 /γ-Fe 2 O 3 /GO) were prepared by a facile self-assembly method. The characterization results show that the x TiO 2 /γ-Fe 2 O 3 /GO have the advantages of narrow band gap energies (<2.47 eV), and high structure stability. The incorporation of TiO 2 into γ-Fe 2 O 3 /GO composite dramatically enhances the catalytic activity, and the 0.03TiO 2 /γ-Fe 2 O 3 /GO composite exhibits the highest catalytic efficiency (99%) for ciprofloxacin (CIP) degradation (10 mg/L, 50 ml) within 140 min under visible light, which is ~1.5 times higher than that of γ-Fe 2 O 3 /GO composite without TiO 2 . Furthermore, the photo-Fenton like mechanism was proposed by quenching experiment and electrochemistry method. The intermediates of the CIP degradation were analyzed by the assistance of LC-MS technology, which provides insight into the pathway of CIP degradation.
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POLYMER
·
2018
·
IF 3.483
Xi-Chuan Li,Chuan-Shan Hu,Hui-Juan Li,Peng-Yun Li,Abdul Haleem,Wei-Dong He
Ring-opening polymerization (ROP) of N-carboxy-α-amino acid anhydride (NCA) of γ-benzyl l -glutamate (BLG) was investigated under frozen condition for the first time. This cryo-ROP was performed in DMSO or 1,4-dioxane below the freezing point of polymerization mixture. The kinetics was monitored with proton nuclear magnetic resonance spectroscopy and gel permeation chromatography , disclosing the well control over molecular weight , living polymerization features and considerable polymerization rate. Compared with the polymerization proceeded at 30 °C, which showed weak linearity regarding the reaction kinetics and relatively broad distribution of molecular weight, the cryo-ROP exhibited excellent first-order kinetics as well as narrow molecular distribution.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Tingwei Zhang,Yijuan Lu,Wenzhi Li,Mingxue Su,Tao Yang,Ajibola Ogunbiyi,Yongcan Jin
In order to efficiently produce γ-valerolactone (GVL) from furfural , a Zr-graphitic carbon nitride/H-β composite (Zr CN/H-β) had been simply prepared via an impregnation-calcination protocol. The morphology and structure, elemental information, and total acid and base properties of the Zr CN/H-β and related catalysts (H-β, CN/H-β, and Zr/H-β) were determined by SEM, TEM , X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption (TPD-NH 3 , CO 2 ) characterizations. The effects of reaction temperature and time, and the furfural dosage on GVL production as well as the recyclability of Zr CN/H-β were investigated. With a catalyst/furfural dosage of 0.1/0.22 g, the Zr CN/H-β produced a remarkable 76.5% of GVL yield at 160 °C in 18 h using isopropanol as the solvent. The results of NH 3 , CO 2 -TPD experiments indicated that the simultaneous introduction of Zr species and carbon nitride onto H-β formed new types of acid and base, which should be responsible for the high efficient conversion of furfural to GVL. Additionally, the recyclability of Zr CN/H-β was reasonable.
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RSC Advances
·
2018
·Vol. 8
·期 61
·35014-35022
·
IF 2.936
Menglu Song,Xiangui Yang,Gongying Wang
γ-Al2O3 loaded with potassium nitrate (KNO3/Al2O3) catalysts were prepared, characterized and employed as a type of heterogenous solid base catalyst in the synthesis of polycarbonate (1,4-butane carbonate)-diol (PBC–OH) via the transesterification of dimethyl carbonate (DMC) and 1,4-butanediol (BD). The relationship between physicochemical properties and catalytic performance for KNO3/Al2O3 in this transesterification reaction was investigated using various techniques. The results demonstrated that the performance of KNO3/Al2O3 catalysts was highly influenced by basic site amount and strength. The medium and strong basic sites were beneficial for this reaction. The catalyst with a KNO3 loading of 35% and a calcination temperature of 700 °C exhibited the best catalytic activity due to its highest basic site amount and appropriate base strength. The highest BD conversion and PBC–OH yield of 80.2% and 68.4% were obtained under optimal reaction conditions. Also, this solid base catalyst was successfully employed in the synthesis of copolycarbonate diols from DMC and two different diols. Different scanning calorimetry results indicated that the thermal properties of the copolycarbonate diols can be adjusted by regulating the average segment lengths, Mn and copolymer composition structure.
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高影响因子
JOURNAL OF POLYMER ENGINEERING
·
2018
·Vol. 39
·期 1
·16-24
·
IF 0.778
Xiaochao Liu,Dengwang Lai,Yuejun Liu,Pu Shi,Wenzhi Wang,Jinghua Tan,Long Mao,Jun Yang
In this study, PA6-66/γ-aminopropyltriethoxysilane-modified clay nanocomposites were prepared by in situ polymerization. It was found that the γ-aminopropyltriethoxysilane was chemically grafted onto clay successfully, and the covalent bond was formed between the clay and polymer chains. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) results indicated that intercalated and exfoliated nanocomposites were obtained. The PA6-66 nanocomposites exhibited improved mechanical performance compared to that of neat PA6-66. Most importantly, the PA6-66 nanocomposites showed significantly improved toughness. In comparison with neat PA6-66, the rupture stress and elongation at the break of the nanocomposite with only 0.5 wt% clay increased 91.9% and 91.8%, respectively. The excellent toughness of PA6-66 nanocomposites should be mainly ascribed to the combined effects of strong polymer-clay interaction, the intercalated-exfoliated structures of clay, refined crystalline, formation of γ-form crystals, and decreased crystallinity of PA6-66.
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Catalysis Science & Technology
·
2015
·Vol. 5
·期 6
·3333-3339
·
IF 5.426
Dong-Mei Lv,Zhong-Ning Xu,Si-Yan Peng,Zhi-Qiao Wang,Qing-Song Chen,Yumin Chen,Guo-Cong Guo
(Pd–CuCl2)/γ-Al2O3 catalyst with excellent activity and selectivity has been successfully developed for vapor-phase carbonylation of methyl nitrite to dimethyl carbonate (DMC). It has been demonstrated that Cl− is necessary for the superior selectivity (99.8%) to DMC, and that Cl− and Cu2+ have a synergetic effect. The Lewis acid sites of the γ-Al2O3 support may be suitable for vapor-phase carbonylation of methyl nitrite to DMC. Moreover, the catalytic mechanism of DMC formation on the (Pd–CuCl2)/γ-Al2O3 catalyst has been reasonably proposed based on the results of XPS and in situ diffuse reflectance infrared spectroscopy. The intermediate Cl–Pd(II)–COOCH3 is the key factor for the synthesis of DMC.
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高影响因子
Journal of Materials Chemistry B
·
2014
·Vol. 3
·期 6
·1020-1031
·
IF 0
Jianjun Fang,Qi Yong,Kunxi Zhang,Wentao Sun,Shifeng Yan,Lei Cui,Jingbo Yin
In search of an injectable cellular delivery vehicle for tissue regeneration, porous microspheres fabricated from the synthetic polypeptide of poly(γ-benzyl-L-glutamate) (PBLG) were developed. The structural and morphological characteristics of the microspheres could be adjusted by changing the amounts of the gelatin porogen. PBLG microspheres fabricated from 6.5% gelatin content exhibited an average pore diameter of 50.9 ± 10.3 μm and a porosity of 86.58 ± 2.37%. Degradation in vitro of the microspheres could be well controlled by adjusting the molecular weight of PBLG, and the degradability in vivo showed a satisfactory degradation time range from 8 to 12 weeks. Articular chondrocytes, which were seeded within the PBLG porous microspheres, exhibited progressive proliferation and deposition of the cartilaginous extracellular matrix. After cultivation for 2 days in vitro, the PBLG porous microspheres loaded with chondrocytes were injected subcutaneously into nude mice. At 4, 8 and 12 weeks post-injection, neo-generated tissue was harvested for histological observations, which showed a typical cartilage structure and cartilaginous matrix accumulation. A gradual increase of GAG and COL II content in neo-generated tissue was detected by biochemical analysis. These results indicate that the fabricated porous microspheres showing controllable degradation properties, good biocompatibility and cytocompatibility are potentially useful as an injectable vehicle for cartilage tissue engineering.
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