COMPOSITES SCIENCE AND TECHNOLOGY
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2020
·
IF 7.094
Yunpeng Liu,Le Li,Hechen Liu,Mingjia Zhang,Aijing Liu,Lei Liu,Li Tang,Guoli Wang,Songsong Zhou
Composite cross-arms have been developed to take place of the steel cross-arm in the power system . In order to suit the environmental impact factors in the long-term operation, superior comprehensive properties of the internally insulated materials for composite cross-arm are required. In the present study, a syntactic foam based on hollow polymer microsphere (HPM)-filled siliconized epoxy resin (SER) was prepared for satisfying these requirements. First, the SER was synthesized using poly (methylphenylsiloxane) and an epoxy resin via a graft reaction. The as-synthesized SER was characterized via Fourier transform infrared, 1 H nuclear magnetic resonance (NMR), and 13 C NMR spectroscopies . Subsequently, a series of SER-based syntactic foams were fabricated using HPM with five different mass fractions. According to the thermogravimetric analysis results, the thermal stability of the composites considerably improved because of the introduction of the siloxane bond. The dielectric constant and dielectric loss of the composites simultaneously decreased with increasing HPM content. The dielectric strength of the composites remained 10.08–21.31 kV/mm after hydrothermal treatment , indicating excellent electrical insulation reliability. Notably, after water diffusion pre-stressing, the leakage current properties of the composites only slightly differed as the HPM content increased. These results further support their application as an internally insulated material for a composite cross-arm.
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高影响因子
OPTIK
·
2020
·
IF 2.187
Mingjing Bian,Hongyan Zhang,Jun Zhang,Zhijun Li
The influence of post-annealing on optical properties of Eu-doped ZnO (ZnO:Eu 3+ ) microsphere synthesized by hydrothermal method has been studied. The intrinsic deep defect emission of ZnO and the transition emission of both 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 related to Eu 3+ have been observed under excitation at 325 nm. The photoluminescence (PL) spectra reveal that ZnO annealed in N 2 is more favorable for Eu 3+ being doped into ZnO, which is helpful to greatly enhance the red light emission of ZnO:Eu 3+ . Alkaline conditions are more conducive to the formation of intrinsic deep defects in ZnO lattice, but they are not so conducive to the doping of Eu 3+ ions into ZnO lattice. From Gaussian deconvolution analysis of PL spectrum for ZnO:Eu 3+ , it can be seen that intrinsic defects of ZnO in N 2 atmosphere may efficiently assist energy transfer from ZnO host to Eu 3+ ions to enhance Eu 3+ intrinsic red light emission. There are blue light (446 nm), green light (525 nm) and stronger red light (618 nm) which are simultaneously obtained. This work could pave a way for high performance of white light emission application.
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高影响因子
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
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2021
·
IF 3.9
Yiheng Sun,Guangjian Peng,Yahao Hu,Guijing Dou,Peijian Chen,Taihua Zhang
The indentation of a microcapsule with a spherical indenter is an effective technique to evaluate the elastic properties of microcapsule shells. The spherical indentation of a microcapsule could be modelled as a microsphere with core–shell structure indented by a rigid sphere. Based on the assumption that the deformed pattern of microcapsule is axisymmetric at small indentation displacement, the deformed profile of shell was divided into five regions according to curvature change. The strain energy of shell was then obtained by adding the bending and membrane strain energy of each region together. The strain energy of core is mainly caused by the volume change of core. The microcapsule was treated as a system and its total potential energy is the sum of the strain energy of shell and core minus the work done by external load. Applying the minimum total potential principle, a spherical indentation model that establishes the relationship among the indentation load, the indentation displacement, and the elastic properties and geometric parameters of microcapsules was proposed. Experiments were carried out on PMMA microcapsules with different dimensions to validate the newly proposed spherical indentation model. The average value of elastic moduli obtained by conventional nanoindentation tests on bulk PMMA and the cross-section of PMMA shell was regarded as the nominal value. The average elastic modulus of PMMA shells determined by the proposed model shows a good agreement with the nominal value. Finally, finite element simulations combined with the proposed model were used to predict the indentation behaviors of microcapsules with different dimensions.
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高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2019
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IF 3.218
Sai Zhang,Yuping Tang,Yanyan Chen,Jianbin Zheng
In this work, 3D flower-like MoS 2 microspheres with nanosheets were synthesized by a simple thiourea-assisted hydrothermal route and employed to support gold nanoparticles in order to fabricate a novel nitrite sensor. By this method, stable and well-distributed gold nanoparticles were formed due to the electrostatic attraction between APTES-functionalized MoS 2 and citric-stabilized gold nanoparticles. Electrochemical investigations indicated that Au NPs/MoS 2 nanocomposites exhibited an excellent performance towards nitrite oxidation . Under the optimal experimental condition (pH 6.0), the sensor displayed a wide linear range from 5.0 μM to 27.8 mM with a high sensitivity of 117.0 μAmM −1 cm −2 and a low detection limit of 1.67 μM. In a word, the present study demonstrates that the Au NPs/MoS 2 composites are promising electroactive materials for developing nitrite sensors with great potential.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2019
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IF 7.65
Yanyan An,Huaili Zheng,Zhishuang Yu,Yongjun Sun,Yili Wang,Chun Zhao,Wei Ding
Rapid, high-efficient adsorbents with efficient solid-liquid separation ability has broad application prospects in the treatment of dye wastewater. In this study, polydopamine and methacryloyloxyethyltrimethyl ammonium chloride were grafted onto hollow glass microspheres to prepare the enhanced polydopamine shell structure adsorbent with self-floating ability. Furthermore, the adsorbent achieves high-efficiency surface solid-liquid separation, which overcomes the disadvantages of the traditional separation methods. Characterizations of the as-synthesized microspheres were performed using various techniques such as SEM, EDS, BET, XPS, FT-IR, TGA and XRD. The adsorbent achieved rapid and high-efficient adsorption of alizarin cyanine green F via the interactions of electrostatic attracting and π-π stacking, and under the optimal experimental conditions, the removal efficiency of 0.10 m mol L −1 dye solution reaches 94.51%, and the adsorption process reaches equilibrium within 60 min. Adsorption isotherms and kinetics data of the adsorbent were well fitted by Langmuir isotherm and pseudo-second-order kinetic models, respectively. The as-synthesized adsorbent has excellent recyclability, and its adsorption performance can be maintained after 5 cycles of reuse. The self-floating adsorbent has great potential for the removal of dissolved contaminants and cost-effective separation.
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2018
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IF 3.779
Junwei Yin,Zipeng Xing,Junyan Kuang,Zhenzi Li,Meng Li,Jiaojiao Jiang,Siyu Tan,Qi Zhu,Wei Zhou
Bi plasmon-enhanced mesoporous Bi 2 MoO 6 /Ti 3+ self-doped TiO 2 microsphere heterojunctions (Bi-BMO/TiO 2-x ) have been synthesized by a mild hydrothermal method combined with an in situ solid-state chemical reduction process, and subsequently annealed at 400 °C in N 2 atmosphere. The prepared Bi-BMO/TiO 2-x photocatalysts are characterized by X-ray diffraction, N 2 adsorption, scanning electron microscopy, transmission electron microscopy , and X-ray photoelectron spectroscopy. The results reveal that Ti 3+ self-doped TiO 2 is loaded on surface of mesoporous Bi 2 MoO 6 microsphere efficiently and metallic Bi is produced for surface plasmon resonance (SPR). Under visible-light irradiation, the heterojunctions photocatalyst shows excellent photodegradation and photoelectrochemical properties of ∼95% for phenol removal rate and 20 μA/cm 2 for photocurrent density, respectively, which is several times higher than that of single component. Moreover, it also has high photocatalytic oxygen production with a rate of 134 μmol h -1 g -1 . The enhanced photocatalytic activities are mainly attributed to the existence of Ti 3+ self-doping and heterojunction structure, which narrow the band gap to extend photoresponse to visible light region. Another reason is the influence of SPR of metallic Bi. They all promote the spatial separation and transfer of photogenerated charge carriers.
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高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
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2019
·Vol. 36
·期 5
·729-739
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IF 2.476
Pan Jiaying,Ou Zhimin,Tang Lan,Shi Hanbing
Racemic 1-phenylethylamine was resolved by enantiomer selective acetylation using Fe 3 O 4 -chitosan microsphere (CTS)-glutaraldehyde-lipase in a solvent-free system under an alternating magnetic field. Magnetic chitosan microspheres (Fe 3 O 4 -CTS) were prepared via chemical co-precipitation and cross-linked with lipase using glutaraldehyde to form Fe 3 O 4 -CTS-glutaraldehyde-lipase particles. The magnetic, physicochemical, and textural characteristics of Fe 3 O 4 -CTS-glutaraldehyde-lipase particles were assessed by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The optimal immobilization conditions were 2.4 mg/mL lipase, 10 mg/mL Fe 3 O 4 -CTS-glutaraldehyde, pH 8.5, 35 °C, 3 h. The loading amount of lipase and the specific activity got to 132 mg/g carrier and 48 U/g. The optimal reaction conditions of the acylation reaction using Fe 3 O 4 -CTS-glutaraldehyde-lipase were 300 mmol/L 1-phenylethylamine, 150 mg immobilized lipase, 2 mL vinyl acetate, 12.6 ×g rotating speed, 40 °C, 8 h. The activity of the Fe 3 O 4 -CTS-glutaraldehyde-lipase particles and conversion were improved when they were exposed to an external alternating magnetic field. The optimum magnetic field was 12 Gs (500 Hz). The conversion, enantiomeric excess of ( R )- N -(1-phenylethyl)acetamide, and E value reached 41.8%, 98.4%, and 264, respectively. Fe 3 O 4 -CTS-glutaraldehyde-lipase could be reused seven times. A kinetic model of the immobilized lipase-catalyzed resolution of 1-phenylethylamine was set up based on the ping-pong bi-bi mechanism. The kinetic constants were V max =1.62×10 −2 mM/min, K A =2.84×10 −4 mM, and K B =5.8×10 −1 mM. The model data fit well with the experimental data.
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高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
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2016
·Vol. 310
·期 2
·611-622
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IF 0.983
Wu Liping,Lin Xiaoyan,Du Xinchen,Luo Xuegang
The carboxymethyl cellulose microsphere loaded with Al(III) (CMC-Al) has been explored for removal of uranium(VI) from U-containing water. Various factors, including pH, adsorbent dosage and uranium(VI) concentration, were tested. Langmuir and Freundlich isotherms were applied to the adsorption data. The thermodynamic parameters such as Δ H °, Δ S ° and Δ G ° were also evaluated. The mechanism of modification and adsorption on CMC-Al were analyzed by SEM, EDX and XPS. Results show Al (III) was loaded on CMC through ion exchange of sodium ion of CMC. The coordination reaction happened during the adsorption process between CMC-Al and uranium(VI).
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高影响因子
Journal of CO2 Utilization
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2017
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IF 4.292
Chen Zhang,Haiyan Yang,Peng Gao,He Zhu,Liangshu Zhong,Hui Wang,Wei Wei,Yuhan Sun
A series of Cu/ZnO/Al 2 O 3 catalysts with the total weight percentage of Cu and ZnO from 9.94 wt.% to 44.5 wt.% have been prepared by ammonia deposition −precipitation method and tested for methanol synthesis from CO 2 hydrogenation. A Cu/Zn/Al layered double hydroxides (LDHs) precursor can be formed in situ on the surface of microspherical Al 2 O 3 which acts as both support and sole source of Al 3+ cations. With increase of total Cu and ZnO loading, the dispersion of copper and reducibility of CuO decline continuously, while the exposed copper surface area increases gradually. In addition, the formation of LDHs results in a stronger both basicity and acid strength on the catalyst surface. It is found that the CO 2 conversion increases linearly with increase of the Cu and ZnO loading. The methanol selectivity for the catalyst with low total metal loading (9.94 wt.%) is much lower than those for other catalysts, though it increases with increasing loading, which can be mainly assigned to the much smaller Cu particle size (<5 nm) and the higher ratio of isolated CuO phase. Moreover, the Cu/ZnO/Al 2 O 3 catalyst with relatively high total metal loading (44.50 wt.%) still exhibits a considerable stable catalytic performance due to the formation of LDH structure.
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高影响因子
RSC Advances
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2016
·Vol. 6
·期 24
·19878-19886
·
IF 3.289
Guoling Wu,Lisong Xiao,Wei Gu,Weidong Shi,Dayu Jiang,Chunbo Liu
Extending the light absorption range and facilitating the separation of photoinduced carriers are effective strategies in the process of improving photocatalysis. An effective method is to construct a heterostructure. In this work, a new heterojunction, CdS/SrTiO3, was synthesized via a two step hydrothermal route and designed to decontaminate hazardous wastewater containing antibiotics under visible light irradiation. Specially, the efficient photocatalytic performance of the composites could be ascribed to the enhancement of visible light absorption efficiency and the efficient separation of the photoexcited carriers originating from the heterointerface. Furthermore, a plausible photocatalytic mechanism has been discussed in detail based on trap experiments and ESR analysis results. The CdS/SrTiO3 heterojunction has potential to be applied for purifying antibiotic pollutants in environmental wastewater because of its high efficiency and stability.
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高影响因子
Arabian Journal of Chemistry
·
2024
·
IF 5.3
Lu-Shuang Li,Su Li,Zong-Mei Huang,Yan-Ting Song,Wei Gong,Jing Li
The abuse of oxytetracycline (OTC) leaves serious environmental residues and triggers accumulation in organisms, constituting a threat to human health. Constructing an effective platform based on dual-functional materials for monitoring and removing OTC residues is a preferable solution. Herein, we proposed a novel composite material by doping carbon dots (CDs) into melamine–formaldehyde microsphere (MFM) through a one-pot method and named CDs@MFM, which inherited the fluorescence property of CDs and porous structure of MFM simultaneously. CDs@MFM demonstrated dual functions for the detection and removal of OTC concurrently within a few minutes, with its performance compared in detail with bare CDs and MFM as controls. By virtue of the pre-enrichment effect attributed to its porous structure, CDs@MFM exhibited a lower detection limit for OTC than bare CDs (0.027 mg/L vs 0.067 mg/L) and a higher adsorption capacity than MFM (73.01 mg/g vs 68.76 mg/g) resulting from more affiliated functional groups available for OTC provided by the CDs. Overall, CDs@MFM has proven to be an efficient and convenient candidate capable of monitoring and removing OTC synchronously, and this work offers an avenue for the design of dual-functional materials in the field of environmental science.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Wan Zhou,Minjun Zhang,Xinjie Liu,Wajid Hussain,Baoan Zhu,Huibin Yu,Shenqi Wang,Lei Zhou
Hemoperfusion is one of the most effective treatments for the removal of bilirubin from the blood. Chitosan (CS) has been widely investigated as a hemoperfusion adsorbent to remove bilirubin due to its biocompatibility and biodegradability. However, the limited adsorption capacity of CS for free bilirubin or albumin-rich bilirubin solution, and the strong adsorption for albumin, limit its extensive use. The goal of this work is to improve specific bilirubin adsorption of CS while reducing its adsorption for albumin. In this study, collagen (Col) was chosen as a ligand and grafted onto the surface of CS microspheres to form CS-Col microspheres and therefore to improve their adsorption performance for bilirubin. The maximum adsorption capacity of the CS-Col microspheres for bilirubin increases from 24.2 to 76.9 mg/g. The enhancement factor is higher than that of other CS-based adsorbents. Moreover, the adsorption of CS-Col microspheres for albumin is effectively reduced to 2.6 %, while maintaining good blood compatibility. Compared to other CS-based bilirubin adsorbents, our CS-Col microspheres have the advantage of specific adsorbing bilirubin against albumin due to introducing collagen. This work provides new directions for designing high-performance bilirubin adsorbents. Our CS-Col microspheres show great promise for the treatment of hyperbilirubinemia.
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高影响因子
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