JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2011
·Vol. 323
·期 23
·3087-3091
·
IF 1.69
L.D. Zhang,W.L. Liu,C.L. Xiao,J.S. Yao,Z.P. Fan,X.L. Sun,X. Zhang,L. Wang,X.Q. Wang
The use of a block copolymer , poly (styrene)-b-poly (acrylic acid) (PS-b-PAA) to prepare a magnetic nanocomposite was investigated. Poly (styrene)-poly ( t -butyl acrylate) block copolymer , being synthesized by atom transfer radical polymerization , was hydrolyzed with hydrochloric acid for obtaining PS-b-PAA. The obtained PS-b-PAA was then compounded with the modified γ-Fe 2 O 3 , and subsequently the magnetic nanocomposite was achieved. The products were characterized by 1 H NMR, FTIR , gel permeation chromatography , thermogravimetric analysis , transmission electron microscopy and vibrating sample magnetometer . The results showed that the nanocomposites exhibited soft magnetism , with the mean diameter of 100 nm approximately.
研究领域:
材料科学
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高分子化学
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纳米复合材料
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磁性材料
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2023
·
IF 8.4
Changcheng Wei,Jinzhe Li,Zhongmin Liu
The utilization of renewable biomass using γ-valerolactone (GVL) as a platform is a sustainable and important route for the production of valuable chemicals. Herein, the selective transformation of GVL to 1,3-butadiene over zeolite catalysts under ambient pressure and continuous flow conditions was reported. Effects of zeolite topologies, acid density, reaction temperature, and contact time on the GVL conversion were systematically investigated. A 1,3-butadiene selectivity of 71% and GVL conversion of 100% were achieved over the NaZSM-35 catalyst at 400 °C. Further investigations revealed that the GVL-to-butadiene reaction might proceed by the following reaction route: GVL was first converted to pentenoic acid (PEA) and then dehydrated into acylium ions, further converting to 1,3-butadiene by decarbonylation. This work provided a promising route for the sustainable and selective production of 1,3-butadiene from renewable materials.
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高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2023
·
IF 1.8
Kai Fei,Zhuo Yi Dong,Li Shi,Xuan Meng,Naiwang Liu
Transformer oil plays a critical role in ensuring the insulation and normal operation of power transformers. However, during operation, the transformer oil would undergo oxidation and degradation, leading to the formation of acids and polar compounds that increase its acidity and degrade its performance. Hence, the recycling and regeneration of aged transformer oil is an essential practice in transformer maintenance, contributing significantly to the extension of a transformer's operational lifespan and the reduction of potential risks. Adsorption separation is a preferred method for regeneration, offering simplicity and high efficiency. This study focuses on impregnated γ-Al 2 O 3 as an adsorbent for acidity removal in waste transformer oil. We conducted static adsorption experiments to investigate the optimal loading amount of the active component and the best calcination temperature for acid removal. XRD technique is employed to monitor the phase changes of the carrier during the calcination process. BET analysis is used to observe variations in the specific surface area and pore volume of the adsorbent during the modification process. DTG-TGA is utilized to assess the weight loss during the calcination process. FTIR is employed to observe changes in functional groups during modification and adsorption processes. Along with these investigations, a study is also carried out to assess the dynamic acid removal performance of the acid-removing adsorbent loaded into a fixed bed. The findings contribute to the development of sustainable methods for regenerating transformer oil, ensuring efficient and environmentally friendly operations.
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FUEL
·
2019
·
IF 5.128
Xue-Ke Li,Zhi-Min Zong,Yi-Feng Chen,Zheng Yang,Guang-Hui Liu,Fang-Jing Liu,Xian-Yong Wei,Bao-Jun Wang,Feng-Yun Ma,Jing-Mei Liu
A highly active difunctional Ni-Mg 2 Si/γ-Al 2 O 3 was prepared by thermally decomposing nickel tetracarbonyl onto γ-Al 2 O 3 impregnated with Mg 2 Si. The non-catalytic hydroconversion (NCHC) and catalytic hydroconversion (CHC) of the extract ( E ) and extraction residue (ER) from Yinggemajianfeng lignite were investigated over Ni-Mg 2 Si/γ-Al 2 O 3 at 240 °C in n -hexane. Benzyloxybenzene and oxybis(methylene)dibenzene were used as lignite-related model compounds to speculate the possible mechanisms for the catalytic hydrocracking and hydrogenation over Ni-Mg 2 Si/γ-Al 2 O 3 . As a result, more organic matter in ER was converted to soluble portion (SP) by the CHC than by the NCHC. The main SP from the CHC are chain alkanes and cyclanes, while that from the NCHC is rich in arenes and oxygen-containing organic compounds. The results indicate that Ni-Mg 2 Si/γ-Al 2 O 3 effectively catalyze the hydrocracking of >C alk –O– linkages and the hydrogenation of aromatic rings in E and ER.
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MOLECULES
·
2022
·Vol. 27
·期 7
·2119
·
IF 4.927
Xue-Li Liu,Yi-Fan Chen,Jing-Jing Yang,Si-Jin Li,Hua-Le Xie,Tian-Lin Ma
A new type of hydroxyalkyl starch, γ-hydroxypropyl starch (γ-HPS), was prepared by etherification of alkali-activated starch with 3-chloropropanol. The reaction efficiency, morphological change, thermodynamic and apparent viscosity properties, and other physicochemical characteristics were described. The molar substitution (MS) of modified whole starch was determined to be 0.008, 0.017, 0.053, 0.106, and 0.178, with a ratio of 5%, 15%, 25%, 35%, and 45% 3-chloropropanol to starch (v/w), respectively. Compared to native starch, the granular size and shape and the X-ray diffraction pattern of γ-HPS are not very different. For low-substituted γ-HPS, the implications may be less evident. Thermal stability measurements by means of thermogravimetric analyses and differential scanning calorimetry (TGA-DSC) proved that thermal stability was reduced and water retaining capacity was increased after hydroxypropylation. Furthermore, the findings also showed that the solubility, light transmittance, and retrogradation of γ-HPS pastes could be improved by etherification. The greater the MS of the γ-HPS, the more its freeze–thaw stability and acid resistivity increased. In this study, we provide relevant information for the application of γ-HPS in food and non-food industries.Keywords:γ-hydroxypropyl starch;molar substitution;physicochemical properties
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PubMed
高影响因子
Applied Materials Today
·
2021
·
IF 10.041
Jie Yang,Yong Liu,Jia Li,Min Zuo,Wenzheng Li,Ningning Xing,Chengyan Wang,Tingting Li
Micromotors have hold great promise for environmental remediation. Herein, we reported a novel γ-Fe 2 O 3 @Ag-mSiO 2 NH 2 magnetic Janus micromotor for dynamic removal of heavy metal ions and organic pollutants from water. The as-prepared Janus micromotors displayed unique core-shell structure composed of amino-functionalized meso‑SiO 2 shell and γ-Fe 2 O 3 magnetic core, and could be propelled by O 2 bubbles generated by Ag-catalyzed decomposition of H 2 O 2 . This Janus micromotor could move with a high velocity of 203.06 ± 10.6 μm s −1 (about 253.8 body lengths s –1 ) in 10 wt.% H 2 O 2 solution. γ-Fe 2 O 3 @Ag-mSiO 2 NH 2 magnetic Janus micromotor showed much higher removal capacities for Cu 2+ (15.59 mg g −1 ) and doxycycline (31.45 mg g −1 ) than its static control samples due to the synergy of self-propulsive movement and amino-functionalized porous core-shell structure. Furthermore, the magnetic γ-Fe 2 O 3 cores enabled the remote magnetic control on the movement direction and magnetic recycling. This work provides a new strategy for environmental pollutants treatment.
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高影响因子
Materials Today Chemistry
·
2021
·
IF 8.301
H. Zhang,J. Xu,S. Wang,Q. Liu,X. Kong
Iron-based nanostructured materials are desirable for various applications owing to their high magnetization. Herein, we presented a facile fabrication of free-standing γ-Fe 2 O 3 nanosheets by a molten salt method for microwave absorption. Furthermore, Al component was incorporated to serve as the template for hole production. The designed holey γ-Fe 2 O 3 nanosheets were effective to maximize the usage of nanomaterials, thereby providing larger surface area, richer defects, and more polarization centers. Both experimental measurements and electric field simulation showed an enhanced capability for microwave absorption using holey γ-Fe 2 O 3 when compared with its intact counterpart. Oxygen vacancy was generated during the hole evolution, which significantly improved the electrical conductivity and thus promoted the conductive loss mechanism. In addition, the holey configuration may extend the transmission path of microwave and confer it with multiple reflection and scattering within the absorbent matrix. Meantime, the polarization loss was strengthened owing to Al modulation associated with the induced defect sites. With the improvement in conductive loss, polarization, impedance matching, and attenuation constant, the as-synthesized holey γ-Fe 2 O 3 exhibited promising microwave absorbability, with a maximum reflection loss of 52.4 dB and an effective bandwidth of 5.12 GHz at a thickness of 2.2 mm, overperforming most pure Fe-based materials.
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Results in Physics
·
2021
·
IF 4.476
Shutong Hao,Xiaolin Liu,Mu Gu,Jiajie Zhu
γ-CuI is a promising scintillator owing to the ultrafast decay time of 130 ps contributed by the near-band-edge emission. The luminescence properties of the γ-CuI are directly related to its intrinsic defects, such as Cu and I vacancies. In this context, tuning the intrinsic defects by cation and anion doping was proposed to improve the scintillation performance of γ-CuI. The structural properties of the dopants, including Li, Na, Mg, F, Cl and Br, were investigated by first-principles calculations. The Li, Na and Mg atoms were calculated to occupy the Cu site. The Cl and Br atoms turned out to replace the I atoms. Importantly, the Cu vacancies were created by Cl and Br dopants, and the I vacancies were eliminated through Li, Na, Mg, Cl and Br doping. These theoretical results were demonstrated by photoluminescence and X-ray excited luminescence spectra.
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JOURNAL OF CATALYSIS
·
2016
·
IF 7.354
Xuelin Zou,Zebao Rui,Shiqi Song,Hongbing Ji
Poor durability and low Pd utilization efficiency are the main drawbacks of supported Pd catalysts for low-temperature methane combustion. Here, we present a facile way to stabilize the performance of Pd/Al 2 O 3 by introducing a spinel NiAl 2 O 4 interface as a promoter at no cost to the activity. The NiAl 2 O 4 interface is formed by impregnation of alumina supports in the nickel-containing solution, followed by high-temperature calcination. A series of 0.4 wt.% Pd/ x NiO/γ-Al 2 O 3 with NiO loading varying among 0.0, 0.5, 1.0, and 9.0 wt.% is investigated. The formation of a NiAl 2 O 4 interface promotes the distribution and crystallization of PdO, suppresses PdO particles aggregation and surface OH − species accumulation during the reaction, and finally leads to the excellent performance of Pd/0.5NiO/γ-Al 2 O 3 . Pd/0.5NiO/γ-Al 2 O 3 demonstrates higher Pd utilization efficiency than the state-of-the-art Pd-based catalysts and better stability than Pd/Al 2 O 3 . Such a spinel interface promotion strategy may bring new insight into the design of highly efficient Pd-based catalysts and their potential technological applications.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2017
·
IF 3.012
Aijuan Xie,Feng Tao,Chao Jiang,Wenliang Sun,Yanfang Li,Lina Hu,Xiang Du,Shiping Luo,Chao Yao
The different crystallographic structures of manganese dioxide (α-MnO 2 , β-MnO 2 , γ-MnO 2 and δ-MnO 2 ) were prepared via simple and feasible methods. Among four crystallographic structures, γ-MnO 2 exhibited the best electrochemical property and was chosen to compound γ-MnO 2 /polyaniline (PANI) composite electrode through in situ synthesis techniques. The as-prepared samples were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). The electrochemical properties of as-prepared samples influenced by the different mass ratios, scan rates, and current densities were mainly investigated by cyclic voltammetry (CV), galvanostatic charge-discharge, electrochemical impedance spectroscopy (EIS), and cycle life, respectively. The results showed that the specific capacitance can be up to 493 F g − 1 as mass ratio of γ-MnO 2 /PANI was 1:5 at current density of 0.5 A g − 1 , suggesting the γ-MnO 2 /PANI (1:5) composite as an electrode material for super capacitors has great development prospects.
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ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Wei Xiong,Lin Qi,Ning Jiang,Qi Zhao,Lingxiao Chen,Xin Jiang,Yuan Li,Zaigang Zhou,Jianliang Shen
Photodynamic therapy (PDT) is a promising strategy for cancer treatment. It can not only generate reactive oxygen species (ROS) to cause the chemical damage of tumor cells in the presence of enough oxygen but also promote the antitumor immunity of T cells through enhancing the production of interferon γ (IFN-γ). However, one phenomenon is ignored so far that the enhanced production of IFN-γ caused by PDT may significantly increase the expression of programmed death-ligand 1 (PD-L1) on the tumor cell membrane and thus could inhibit the immune killing effects of T cells. Herein, we report the construction of a composite by loading metformin (Met) and IR775 into a clinically usable liposome as a two-in-one nanoplatform (IR775@Met@Lip) to solve this problem. The IR775@Met@Lip could reverse tumor hypoxia to enhance ROS production to elicit more chemical damage. Besides, the overexpression of PD-L1 by PDT was also effectively down-regulated. These therapeutic benefits including decreased PD-L1 expression, alleviated T cell exhaustion, and reversed tumor hypoxia successfully suppressed both the primary and abscopal tumor growth in bladder and colon cancers, respectively. Combining with its excellent biocompatibility, our results indicate that this IR775@Met@Lip system has great potential to become a highly effective cancer therapy modality.
研究领域:
癌症研究
·
药学
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免疫治疗
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纳米技术
·
生物医学工程
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DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2021
·Vol. 23
·期 18
·7065-7073
·
IF 10.182
Liang Jiang,Guangyue Xu,Yao Fu
The conversion of levulinic acid (LA) to γ-valerolactone (GVL) is one of the most important reactions from biomass-derived platform chemicals to value-added chemicals. In this work, nitrogen-doped carbon was introduced into a Ni/Al2O3 catalyst and was employed for the hydrogenation of LA to GVL with a full conversion and equivalent yield under mild conditions, at as low as ambient hydrogen pressure and 130 °C for 6 h. The doping of nitrogen introduced NiNx species and the imperfection of modified nitrogen-doped carbon were beneficial for the selective hydrogenation of carbonyl groups. This catalyst showed excellent activity and selectivity in various solvents and could be recycled for at least 6 runs with little deactivation. In addition to LA, various substrates with both carbonyl and carboxyl groups could also be selectively hydrogenated to the corresponding lactones. This study offers both theoretical foundation and practical instructions for the high-efficiency conversion of LA to GVL over non-noble metal catalysts under mild conditions, especially ambient H2 pressure.
研究领域:
催化化学
·
生物质能转化
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高影响因子
危险品化学品经营许可证（带存储）