MATERIALS SCIENCE FORUM
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2017
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IF 0
Zhao Bing Cai,Xue Jia Pang,Xiu Fang Cui,Xin Wen,Zhe Liu,Mei Ling Dong,Yang Li,Guo Jin
In order to improve the surface properties of Ti-6Al-4V, high-entropy alloy coatings were prepared by in-situ laser cladding on the surface of Ti-6Al-4V substrate. The microstructure, micro-hardness, corrosion resistance and wear resistance were investigated. The results showed that the high-entropy alloy coating was composed of BCC high-entropy alloy phase, α-Ti phase and (Ni, Co)Ti2 phase. The micro-hardness of the high-entropy alloy coatings is much higher than that of Ti-6Al-4V substrate. The coating also has a better corrosion resistance than Ti-6Al-4V substrate, even superior to 304SS in 3.5wt.% NaCl solution at room temperature. Compared with Ti-6Al-4V substrate, the high-entropy alloy coating has a greater wear resistance with the wear mass loss decreased 28.2% and 23.1%, respectively. Wear patterns of Ti-6Al-4V substrate and high-entropy alloy coatings are the coexistence of adhesive wear and abrasive wear, but the wear degree of high-entropy alloy coatings is lower.
研究领域:
材料科学
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表面工程
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产品关联
DOI
MATERIALS SCIENCE FORUM
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2017
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IF 0
Heng Xue Xiang,Zi Ye Chen,Wei Chen,Zhe Zhou,Bin Sun,Mei Fang Zhu
As a potential material for food packaging, fully biodegradable composite films based on novel functionalized natural polyphenol/Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were successfully fabricated by solution casting, and also the functionalized natural polyphenol (C18TAx) was synthesized by grafting fatty acid onto natural polyphenol Tannic Acid (TA). The resultant C18TAx with better hydrophobicity was uniformly dispersed into a PHBV matrix. The influence of C18TAx dosage on the mechanical behavior, crystallization behavior and thermal properties of the C18TAx/PHBV composite films was investigated by uniaxial tensile mechanical testing, Differential Scanning Calorimeter (DSC), Polarizing Optical Microscope (POM) and Wide Angle X-ray Diffractometry (WAXD). The results revealed that the x value was about 0.09, showing that about 11/20 phenol hydroxy groups in TA molecules were replaced with fatty acid chains. Compared with those of neat PHBV, the tensile strength and elongation at break of the C18TA0.09/PHBV composite films with 10 wt.% C18TA0.09 content were enhanced by 121%, and 458%, respectively. This improvement was primarily ascribed to intermolecular hydrogen bonding interactions in composite films. This new type of fully biodegradable bio-based composite films shows great potential for food packaging.
研究领域:
材料科学
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食品科学
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产品关联
DOI
MATERIALS SCIENCE FORUM
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2018
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IF 0
De Zhi Wang,Yu Qing Zhang,Bo Hua Duan
In this work, Molybdenum trioxide and conventional copper particles were used as precursors, reduced in hydrogen atmosphere. Then Cu@Mo Powders were successfully synthesized. Effects of reduction temperature on the microstructure of the composite powders and the performance of the intermediate product (molybdenum dioxide) were investigated. Results show that 700°C is the optimal reduction temperature, because Mo is reduced from its oxide and forms a coating layer on the surface of copper particles tightly without serious crack. Mo-20wt.% Cu composite powders where Cu is coated uniformly with continuous molybdenum layer are successfully obtained by co-reduction method.
研究领域:
材料科学
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化学工程
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产品关联
DOI
MATERIALS SCIENCE FORUM
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2018
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IF 0
Miao Ying Jin,Shi Yan Chen,Bao Xiu Wang,Hua Ping Wang
Wound healing is accompanied by keloids, it is important to develop a wound dressing which can inhibit keloid and relieve pain and pruritus in patients. In this paper, bacterial cellulose/triamcinolone acetonide (BC/TA) composites are prepared by easy solution impregnation method, which the structures of BC/TA composites were analyzed by fourier transform infrared spectroscopy (FTIR). The drug release and inhibition of L929 cells were also analyzed. It can be concluded that BC/TA composites have a sustained release effect on TA and can effectively inhibit proliferation of L929 in the range of 0.5-2.0 mg/cm2.
研究领域:
生物医学工程
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药理学
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产品关联
DOI
MATERIALS SCIENCE FORUM
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2018
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IF 0
Rui Min Zhao,Xian Ya Xue,You Fa Wang
Porous Hyaluronan/β-tricalcium phosphate composite scaffolds were synthesized through lyophilizing and subsequent heterogeneous crosslinking method. The morphology of the composite scaffolds were investigated by scanning electron microscopy (SEM). The swelling behavior, mechanical property, degradation behavior and cell adhesion ability of samples were also studied. The results revealed that hyaluronan mainly contributed to the polymer matrix and water adsorption, whereas β-TCP acted as a reinforcement to strengthen the porous structure, while too much β-TCP would make the structure collapse. The pose size of obtained scaffolds ranges from100μm to 200μm and the porosity decreased with the increase of β-TCP content. The degradation behavior and cell adhesion test indicated that increasing hyaluronan concentration can effectively improve the degradability of scaffolds and the incorporation of β-TCP improved the cell adhesion performance. Thus a simple way to prepare hyaluronan-based composite scaffolds was provided, which could be potentially used as an tissue engineering material.
研究领域:
生物材料
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组织工程
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生物医学工程
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产品关联
DOI
MATERIALS SCIENCE FORUM
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2018
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IF 0
Hui Meng Wang,Ming Zhou Su,Chang Chen
Steel foams have been receiving a growing interest due to the unique structural properties. The space holder technique provides a high degree of freedom and allows to produce this kind of materials varying in a wide range of porosity. However, the accurate prediction of final porosities has been a difficult problem in this technique. Therefore, a nonlinear equation between spacer content (φ1) and porosity (P) of the sintered steel foams was established in this study when macropores, micropores and their volumetric change were taken into account at the same time, that was P = (aφ1+b)/(cφ1+d). Then, validation of the theoretical relationship was carried out using the experimental data by authors and other researchers. The results showed that the porosity could be well predicted by the nonlinear relationship with varied preparing parameters. One set of coefficients in the model equation, i.e., a, b, c, d, corresponds to a certain preparing condition, while these values changed in different preparing conditions.
研究领域:
材料科学
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工程学
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DOI
MATERIALS SCIENCE FORUM
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2017
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IF 0
Ying Pan,Lei Song,Yuan Hu
Bio-based and phosphorus-free coating was fabricated by layer-by-layer assembly method to obtain the flame retardant polyester-cotton fabric. For the first time, the modified polyester-cotton fabrics were prepared by utilizing positively charged polyethylenimine and negatively charged alginate together with subsequent crosslinking of calcium ion. Scanning electron microscopy and energy-dispersive X-ray demonstrated that the calcium ion crosslinked coating was successfully constructed on the substrate. The flame retardancy was investigated by horizontal flame test. The fire resistance of SA/PEI-Ca sample was enhanced significantly compared with the pure sample, as evidenced by the obvious reduction (16%) of flame spread rate and complete char residue.
研究领域:
材料科学
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纺织工程
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产品关联
DOI
MATERIALS SCIENCE FORUM
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2014
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IF 0
Dan Zhao,Juan Chen,Qun Gao,He Yi Ge
Graphene oxide (GO) synthesized through a modified Hummers’ method was added into cement matrix to prepare GO/cement. The microstructure, mechanical properties, and the electromagnetic shielding effectiveness (SE) at 8.2–12.4 GHz of GO/cement composite were investigated. It has been observed that incorporation of GO in the cement matrix can regulate to form flower-like hydration crystals and distinctly enhance the flexural/compressive early stage strength of GO/cement composites. Furthermore, GO sheets played a vital role in effectively improve the shielding effectiveness with the dominant shielding mechanism of absorption of electromagnetic radiation.
研究领域:
材料科学
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电磁学
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DOI
MATERIALS SCIENCE FORUM
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2014
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IF 0
Zhi Jia Luo,Hong Zhang Geng,Song Ting Zhang,Bao Tan Du,Xing Zhang,Jing Wang,Zhan Guo Lu,Su Jun Ma,Jin Qiu Zhang,Hai Jie Yang,Jie Wang
Graphene oxide (GO) is typically synthesized by graphite powder under strong oxidizing reaction, possessing with the same set of functional groups: epoxy and hydroxyl in basal plane and carboxyl and hydroxyl groups existence on the flake edges which endow GO with amphipathy. GO and its functionalized derivatives have been successfully tested in many domains, such as polymer composites, biosensors, drug delivery systems, etc. In this paper, GO was prepared by a modified Hummers method employing improved process (preparation and separation), aiming at industrialization with the lowest cost. Moreover, some novel functional groups with different properties were controlled chemically grafted onto GO to modify the wettability and reaction activity with other materials. The hydrophobicity and the thermal property of graphene oxide were enhanced by chemical functionalization.
研究领域:
材料科学
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化学工程
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DOI
MATERIALS SCIENCE FORUM
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2014
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IF 0
Lu Liu,Hui Ren,Qing Jie Jiao
Due to high reaction activity and high combustion heat release, magnesium is widely used in the field of explosives. The research focus of this article is the effect of magnesium powder size and content on the thermal decomposition of PTFE. Two different particle sizes of magnesium powder are regarded as research objects. The thermal behavior of Mg/PTFE energetic system was investigated by TG-DSC analyzer. The experimental results show that magnesium has a catalytic effect on the thermal decomposition of PTFE. With the increase of magnesium content , the decomposition peak temperature of PTFE decreased firstly and when passed the ratio 50% increased, the best mixing ratio is Mg: PTFE =50:50. Within nanopowder, the activation energy of PTFE decreased by 150kJ∙mol-1 compared to 112 kJ∙mol-1 by mixing with micro powder. Obviously nanopowder has a better reactivity than micro powder, so has a more obvious catalytic effect.
研究领域:
材料科学
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热力学
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DOI
MATERIALS SCIENCE FORUM
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2014
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IF 0
Ye Chuan Chen,Guang Yang,Rui Zhao,Wei Dong Xue
Silicon nanoparticles have extraordinary electrochemical performance for lithium-ion batteries. This paper gives an improved low temperature solution synthesis route of Si NPs. Reduced by magnesium and then passivated by four kinds of amines/amides respectively, stable yellow Si NPs ranging from 5-50 nm were prepared. When passivated by N-methyl-2-pyrrolidone, grape-like aggregation of 5-20 nm particles were generated. FTIR, XRD, SEM and Electrochemical Characterization were performed to confirm the product. The Si NPs passivated by NMP achieve good electrochemical performance with a first discharge capacity of 1154 mAhg-1 at a current density of 200 mAg-1 and good capacity retention of 95.3% after 5 cycles.
研究领域:
材料科学
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能源存储
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DOI
MATERIALS SCIENCE FORUM
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2010
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IF 0
Xin Wang,Yuan Yuan Dou,Mei Shan Pei,Xin De Tang
Biocompatible and biodegradable synthetic materials have attracted considerable attention during the past two decades. In this work, a series of amphiphilic triblock copolymers containing D-galactopyranose were synthesized by atom transfer radical polymerization (ATRP). The macroinitiator was prepared by the esterification between poly(ethylene glycol) monomethyl ether with a number-average molecular weight of 1200 g/mol (MeOPEO-1200) and 2-bromoisobutyryl bromide. The sugar-bearing monomer, 6-O-methacryloyl-1,2;3,4-di-O-isopropylidene-D-galactopyranose (MAIPG) was polymerized using PMDETA/CuBr as catalytic system and anisol as solvent. The chemical structure and composition of the resultant polymer MeOPEO-b-PMAIPG were verified by 1H NMR. The molecular weights and their polydispersities were characterized by gel permeation chromatography (GPC). The results indicate that the polymerization follows the mechanism of ATRP. The amphiphilic copolymers can self-assembly to from micelles with PMAIPG as the core and PEO as the corona, which have potential applications as biomaterials or controlled release drug delivery systems.
研究领域:
高分子化学
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生物医学工程
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药物递送
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材料科学
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大分子化学
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DOI
危险品化学品经营许可证（带存储）