JOURNAL OF ALLOYS AND COMPOUNDS
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2019
·
IF 4.175
Faqing Shi,Limeng Liu,Yujin Wang,Guihong Geng
TaC 0.6 -Cu composites were fabricated by hot pressing of TaC, Ta and Cu powder mixtures. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, scanning-transmission microscopy, X-ray energy-dispersive spectroscopy, and selected area electron diffraction were used to investigate formation process and growth behavior of the ζ-Ta 4 C 3-x lamellae. Cu addition did not change the reaction sequence of TaC + Ta → Ta 2 C + TaC y → ζ-Ta 4 C 3-x to form the targeted ζ-Ta 4 C 3-x phase, but enhanced growth of ζ-Ta 4 C 3-x lamellae by introducing a dissolution-reprecipitation mechanism due to presence of Cu liquid at high temperatures. ζ-Ta 4 C 3-x could directly nucleate and grow on h-Ta 2 C grain surface, meanwhile C immediately reacted with Ta solutes in Cu liquid after the C atoms diffusing along the {111} TaCy stacking faults out of parental γ-TaC y grains to initiate extension of ζ-Ta 4 C 3-x lamella outside the γ-TaC y grains, thus grew large ζ-Ta 4 C 3-x lamellae with a uniform thickness in the microstructure of the TaC 0.6 -Cu composites. The TaC 0.6 -Cu composites with large ζ-Ta 4 C 3-x lamellae in the microstructures showed increase in fracture toughness.
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ChemistryOpen
·
2019
·Vol. 8
·期 1
·58-63
·
IF 2.205
Shujing Chen,Abdelhafid Zehri,Qianlong Wang,Guangjie Yuan,Xiaohua Liu,Nan Wang,Johan Liu
Graphical Steady as she goes : Graphene-encapsulated Cu nanoparticles (GCPs) fabricated by chemical vapor deposition in a cold wall reactor not only exhibited an outstanding thermal stability up to 179 °C, but also display an excellent thermal conductive performance in a thermally conductive adhesive (TCA). Functional fillers, such as Ag, are commonly employed for effectively improving the thermal or electrical conductivity in polymer composites. However, a disadvantage of such a strategy is that the cost and performance cannot be balanced simultaneously. Therefore, the drive to find a material with both a cost efficient fabrication process and excellent performance attracts intense research interest. In this work, inspired by the core–shell structure, we developed a facile manufacturing method to prepare graphene-encapsulated Cu nanoparticles (GCPs) through utilizing an improved chemical vapor deposition (CVD) system with a cold wall reactor. The obtained GCPs could retain their spherical shape and exhibited an outstanding thermal stability up to 179 °C. Owing to the superior thermal conductivity of graphene and excellent oxidation resistance of GCPs, the produced GCPs are practically used in a thermally conductive adhesive (TCA), which commonly consists of Ag as the functional filler. Measurement shows a substantial 74.6 % improvement by partial replacement of Ag with GCPs.
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高影响因子
POLYMER
·
2019
·
IF 3.771
Xiaolin Wang,Rui Yang,Liyan Huang,Jun Li,Zhengping Liu
A series of starch-graft-poly (methyl methacrylate) (S- g -PMMA) copolymers were prepared by single electron transfer living radical polymerization (SET-LRP) at molecular level under mild conditions. The successful grafting polymerization was confirmed by FT-IR and 1 H NMR spectroscopies. The hydrolysate of S-g-PMMA via acid-catalyzed hydrolysis proved to be a mixture of 1-arm, 2-arm and 3-arm polymers by MALDI-TOF measurements. Furthermore, the micelles formed by S-g-PMMA copolymers in water were studied at various conditions by SEM, TEM and DLS measurements. The results indicate that the sizes of micelles decreased following the order of the common solvents of 1,4-dioxane, tetrahydrofuran , acetone and acetonitrile , and also increased with the increase of initial copolymer concentrations, addition rate of water and length of grafted chains.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 10
·9480-9489
·
IF 2.914
Dai Shijin,Zheng Yilin,Zhao Youcai,Li Qiang,Niu Dongjie
Chlorine-containing organic waste (COWs) is a big threat for the waste incineration because of the dioxin generation and equipment corrosion. Recently, dechlorination and detoxification of COWs is emergent in order to lower the environmental risk and treatment costs. In this study, base-catalyzed decomposition processes with different hydroxides, hydrogen donors, and catalysts were conducted for pre-treatment of COWs to reduce organic chlorine content, with the TCB as a model compound and industrial rectification residues for verification. Results showed that maximum chlorine retention efficiency (CRE) of four alkalis followed the order of KOH > NaOH–KOH > NaOH > Mg(OH) 2 , which were 98.3%, 93.4%, 97.2%, and 1.5%, respectively, and could be expressed as an apparent first-order reaction. The differences were resulted from the varying ionic potentials of the metal cations. Hydrogen donors (glycol, glycerol, paraffin oil, and PEG 200) acted as effective dechlorination regents follow the order of PEG > glycol > paraffin oil > glycerol. In addition, Fe, Ni, Cu, and activated carbon catalysts increased the CRE by 68.9% to 92.4%, 91.9%, 89.2%, and 73.3%, respectively. Residue analysis through X-ray diffraction and Fourier transform infrared spectroscopy revealed that KCl, sodium oxalate, and phenol were the main products and a plausible stepwise dechlorination pathway was proposed. The effectiveness of three optimized combinations including NaOH/PEG, KOH/PEG, and NaOH–KOH/PEG (with the Fe catalyst) was confirmed by using them for dechlorinating rectification residues, and they restrained 98.2%, 91.2%, and 94.6% of the chlorine, respectively. The organochlorine content decreased from 19.2 to 1.8% within 180 min, while inorganic chorine content increased from 1.5 to 18.9%, indicating the potential for COWs dechlorination.
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高影响因子
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
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2019
·
IF 2.606
Xia Yan,Shuqing Cao,Ying Li,Pei Xiao,Zipeng Huang,Haiyan Li,Yan Ma
Curcumin (Cur) and its nanomedicine were researched in Caco-2 cells to investigate the internalization and subcellular transport across Caco-2 cell monolayer membrane. Cur loaded polymer micelle (PM), nanoemulsion (NE) and liposome (Lipo) were prepared to explore the transport process incorporating endocytosis, intracellular trafficking and transcytosis in Caco-2 cells. Firstly, nanocarriers could contribute to the cellular uptake and improve the stability of Cur within the Caco-2 cells. The co-mediation of clathrin , lipid raft/caveolae and/or macropinocytosis were involved in the internalization of Cur nanopreparations, indicating the diversity and partial energy-dependency of the endocytosis. Secondly, the endocytosed nanocarriers with Cur successively transported from apical early endosome to late endosome with the extension of incubation time . Furthermore, the intracellular location of Cur nanomedicines in lysosome and endoplasmic reticulum (ER) were detected and illustrated the actual transport of Cur nanomedicine to lysosome and ER. Finally, nanocarriers could enhance the transcytosis of Cur, involving the energy-dependent patterns. Especially, Cur-PM exhibited more advantages in regulating and coordinating the entry and the exit of Cur. The study indicated that the coexistence of multiple transport pathways had the potency to promote nanocarriers transcytosis and provided a rational dosage design for oral Cur.
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WATER ENVIRONMENT RESEARCH
·
2019
·Vol. 91
·期 8
·770-779
·
IF 1.24
Jinhong Fan,Hehe Qin,Yunfei Zhang,Simin Jiang
In this study, Fe/Cu bimetal composite was prepared by high-energy ball milling (BM) method for the removal of refractory organics. The BM Fe/Cu bimetal was characterized by SEM-EDS, XRD, and XPS. Evenly distributed Fe and Cu was observed in the EDS mapping. In contrasting experiments, the removal rate of 4-chlorophenol (4-CP) by BM Fe/Cu materials was about 10-fold faster than that by chemical substitution deposition (CSD) of Fe/Cu material. Complete 4-CP removal and 66.7% of total organic carbon (TOC) mineralization in the BM Fe/Cu–O 2 system were achieved. Dissolved oxygen plays a crucial role for 4-CP degradation through the in situ generation of reactive oxygen species (ROS) such as H 2 O 2 , ·OH, and via oxygen activation reactions. The predominant reactive radicals were identified to be and ·OH through ESR technique and inhibition experiments. The coexistence of oxidation and reduction of 4-CP in the BM Fe/Cu-O 2 system was proposed. Practitioner points 4-CP removal rate by BM Fe/Cu is 10-fold faster than that by CSD Fe/Cu at the same conditions. Complete 4-CP removal and 66.7% of TOC reduction were achieved. All three ROS including ·OH, , and H 2 O 2 coexisted in the BM Fe/Cu-O 2 system. A harmonious coexistence of oxidation and reduction mechanism was proposed.
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高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2019
·Vol. 20
·期 6
·1469
·
IF 4.183
Xuerong Zhou,Ling Zhao,Jie Luo,Huaqiao Tang,Min Xu,Yanyan Wang,Xiaoyu Yang,Helin Chen,Yinglun Li,Gang Ye,Fei Shi,Cheng Lv,Bo Jing
Research has shown that nano-copper (nano-Cu) can cause damage to the spleen and immune system yet their mechanisms of cytotoxicity are poorly understood. Our aim is to explore the potential immunotoxicity in the spleen of rats after nano-Cu exposure. The results of hematologic parameters, lymphocyte subsets, immunoglobulins, and histopathology indicated that copper obviously changed the immune function of the spleen. The levels of antioxidants (SOD, CAT, GSH-Px), oxidants (iNOS, NO, MDA), and anti-oxidative signalling pathway of Nrf2 (Nrf2 and HO-1) were strongly induced by nano-Cu. The expression of mRNA and protein of pro-/anti-inflammatory (IFN-γ, TNF-α, MIP-1α, MCP-1, MIF, IL-1/-2/-4/-6) cytokines were increased by nano-Cu. The expression of regulatory signal pathways, MAPKs and PI3-K/Akt were activated, which might be involved in the inflammatory responses and immunomodulatory processes of sub-acute nano-Cu exposure. The immune function of the spleen was repressed by nano-Cu induced oxidative stress and inflammation.Keywords:nano-Cu;rats;spleen injury;immune system;oxidative stress
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Chunyan Ma,De-Kun Ma,Wenyuan Yu,Wei Chen,Shaoming Huang
Photoelectrochemical (PEC) water splitting that can mimic natural photosynthesis to directly harvest and convert solar energy into clean and sustainable hydrogen energy, has been known as a promising avenue for addressing environmental pollution and energy crisis. Spinel-type CuBi 2 O 4 semiconductor as a promising photocathode material for solar water reduction has attracted much attention because of its many unique advantages. However, PEC activity of pristine CuBi 2 O 4 is far from satisfying because of its poor charge carrier transport and transfer efficiency. Herein we report that Ag + ions and N-doped graphene quantum dots (NGQDs) co-modified CuBi 2 O 4 submicron rods (NGQDs/Ag-CBO SMRs) photocathode can show enhanced PEC activity. Our work demonstrated that one-dimensional structure, Ag + ions doping, and NGQDs loading benefited the separation and transfer of photogenerated carriers and improved light harvesting ability, which were collectively contributed to enhanced PEC activity of NGQDs/Ag-CBO SMRs photocathode. As a result, the photocurrent density achieved on NGQDs/Ag-CBO SMRs photocathode under AM1.5G simulated sunlight at 0.3 V vs. RHE was 8.8, 2.3, 1.8, and 5.9-times larger than those obtained on CBO SMRs, Ag-CBO SMRs, NGQDs/CBO SMRs, and NGQDs/Ag-CBO microspheres (MSs) ones, respectively. The present study provides a new strategy for designing low-cost and highly efficient photocathodes.
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高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Huizhong Chi,Xu He,Jianqiao Zhang,Jun Ma
Degradation of naproxen, bisphenol S and ibuprofen in a hydroxylamine enhanced zero-valent copper (Cu 0 ) catalyzed peroxymonosulfate system was investigated for the first time. We found that hydroxylamine addition accelerated the reduction of Cu 2+ to Cu + as well as the corrosion of Cu 0 , and environmental friendly gas nitrogen was the main product of hydroxylamine. Additionally, hydroxyl radical and sulfate radical were identified to be the dominant reaction species by competitive experiments. The degradation of naproxen, bisphenol S and ibuprofen kept highly efficient in the pH range of 3.0–7.0 in Cu 0 /hydroxylamine/peroxymonosulfate process, with their degradation products identified by HPLC-MS, which showed that Cu 0 /hydroxylamine/peroxymonosulfate system could be an alternative to remove non-steroidal antiinflammatory drugs or plasticizers in wastewater. Furthermore, the effects of Cu 0 , hydroxylamine and peroxymonosulfate dosage were studied and optimized by a BBD based response surface model. This study provided a method to solve the disadvantages of Cu 0 /peroxymonosulfate systems, and gave a promising method to enhance the efficiencies of ZVMs activated system such as iron, cobalt and copper.
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高影响因子
SOLID STATE SCIENCES
·
2019
·
IF 2.155
Jianxun Zhao,Xiangjun Zhou,Yalan Guo,Zhongmin Su,Heng Liu,Wanqiang Liu,Shang Gao
Co 0.9 Cu 0.1 Si alloy was fabricated via mechanical alloying technique. Different amount of palladium was doped into the Co 0.9 Cu 0.1 Si alloy by ball milling. The composite alloy combined the excellent electrocatalysis activity of Pd, exhibiting preferable electrochemical performance than the original alloy. The Co 0.9 Cu 0.1 Si + 5 wt% Pd composite showed a C max of 559.2 mAh/g, significantly higher than that for Co 0.9 Cu 0.1 Si (502.1 mAh/g). The cycle stability was also enhanced after Pd loading. Moreover, the effect of ball milling time on electrochemical performance for the composite alloy was also investigated. 5 wt% Pd was mixed with the Co 0.9 Cu 0.1 Si alloy at different ball milling time (0.5 h, 1 h, 2 h, 3 h and 5 h). The optimal discharge capacity, capacity retention and high-rate dischargeability were obtained under the ball milling time of 2 h. The studies on electrochemical reaction kinetics demonstrated that the addition of Pd could accelerate the charge-transfer, thus enhancing the electrochemical activity and reaction kinetics of the alloy. The results indicated that Pd loading was an effective way in enhancing the electrochemical performance of Co 0.9 Cu 0.1 Si alloy.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Cihui Tian,Sajid Asghar,Ziyi Hu,Yue Qiu,Jingwei Zhang,Feng Shao,Yanyu Xiao
The gliomas treatment is challenging due to the limits imposed by blood-brain barrier to the distribution of the drugs in the brain. Therefore, we designed a brain glioma targeting redox-sensitive hyaluronic acid (HA)-ss-curcumin (CUR) micelles . HA was conjugated to CUR through a disulfide bond , which could form micelles independently in aqueous solution. And we further increased the drug loading by loading free CUR. Brain penetration was achieved with Tween 80, whereas glioma-targeting was inclined by CD44-mediated endocytosis . Compared to the disulfide-free group, the redox-sensitive micelles exhibited rapid in vitro drug release under high glutathione conditions, significantly enhanced cell apoptosis and cellular uptake in G422 glioma cells. Redox-sensitive micelles displayed about 4.70-fold higher area under the curve in rats after intravenous injection in comparison to the free CUR and effectively accumulated in the brain. These findings suggest that redox-sensitive micelles could be a promising candidate to achieve brain targeted CUR delivery.
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高影响因子
CHEMICAL PAPERS
·
2019
·Vol. 74
·期 2
·485-497
·
IF 1.246
Quan Cong,Liu Jiayu,Sun Wei,Cheng Xinjian
It is extremely necessary to detect heavy metals sensitively and selectively, especially the ions that will cause great harm to humans and the environment. This work deals with two fluorescent chemosensors and their outstanding role when detecting Zn 2+ and Cd 2+ ions. First, a small molecular chemosensor (TPB) has been designed and synthesized via Suzuki reaction using one part of benzene-1,3,5-triyltriboronic acid and three parts of 2-bromo-1, 10-phenanthroline as starting materials. And then, its corresponding macromolecular fluorescent chemosensor (PTPB) was synthesized. The infrared spectra, mass spectrometry (MS), and 1 H-NMR were used to study the structures of TPB and PTPB. From what has been studied, the TPB and PTPB were stable in a relative wide pH range. As soon as the Cd 2+ and Zn 2+ ions added, fluorescence of the two sensors TPB and PTPB was changed obviously. In addition, PTPB was found have better performance to both Cd 2+ and Zn 2+ than TPB through the ‘‘molecular wire’’ mechanism. Job’s plots were also be tested, showing that the combination ratio of TPB and PTPB to Cd 2+ and Zn 2+ were both 3:1 (ion/sensor). In addition, the minimum detection limits of the macromolecular chemosensor PTPB for Cd 2+ and Zn 2+ reached 0.424 μM and 1.27 μM, respectively.
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