JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Wei Le,Wanjun Zhao,Yanli Zhu,Xin Zeng,Dazhi Liu,Qingjie Jiao
Aluminum (Al)-lithium (Li) alloys are ambitious candidates for application in energetic materials, however, the high reactivity of Al-Li compound and Li in alloys affects their thermal stability, which results in gradually lower active content and diminished performance, impeding their further application in energetics. In this study, the specific content of silicon (Si) was introduced into Al-Li alloy via the centrifugal atomization that allows in-situ assembly of Al , Li, and Si at the single particle level, thus resulting in more stable Al-Li-Si compounds instead of active Al-Li compounds and Li and enhancing their thermal stability. The results show that Al-Li-Si alloy powders are in a high degree of sphericity, which are composed of αAl and AlLiSi. Compared to Al-Li alloys, Al-Li-Si alloys initiate the oxidization at a higher temperature (∼600 ℃) since the existence of more stable Al-Li-Si compounds than Li in Al-Li alloys, which indicates a higher thermal stability. Al-Li-Si alloys also show high heat release and combustion efficiency similar to Al-Li alloys. In the meanwhile, Al-Li-Si alloy-based composites maintain almost the same combustion properties compared to Al-Li/PTFE energetics, along with prolonged combustion duration. Therefore, Al-Li-Si alloy powders are promising candidates for application in energetic materials considering their higher thermal stability and tunable combustion properties.
研究领域:
材料科学
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能量材料
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Qiang Zhang,Yuxiu Yu,Haojie Li,Fengying Zhang,Yaodong Liu
Binders are expected to play important role in silicon-based anode materials, but have not been well explored. In this work, a serial of silicon containing polyimides and polyamides have been synthesized and used as the binder of high content (80wt%) silicon anode. Systematic characterizations have been done on the chemical structures, physical properties of the binders, and the electrochemical performances of silicon-based anode. It was found that the swelling ratio, adhesion strength, and hardness plays important roles on the initial Coulombic efficiency (ICE) and capacity retention of silicon-based anode, and these parameters highly depend on the types and properties of binders. After optimizing the chemical structures and physical properties of the binders, a high specific capacity of 2941 mAh g −1 , relatively high initial Coulombic efficiency (ICE) of 83%, and good capacity retention of 85% (after 200 cycles) have been obtained. These results would help researchers to design new types of binders for silicon-based anode to improve its ICE and capacity stability.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
Applied Sciences-Basel
·
2023
·Vol. 13
·期 9
·5726
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IF 2.7
Yujia Chen,Wei Tan,Li Li,Hongbing Ji
It is a challenge to research and develop silicon surfactants with good acid and alkali stability. In the present paper, methylpropenyl polyether modified nonionic silicone surfactant (MPNTS), an alkali-resistant and hydrolysis-resistant silicone surfactant, was synthesized by hydrosilylation of 1,1,1,3,5,5,5-heptamethyl trisiloxane (MDHM) and methylpropenyl polyether (EO(7)). The polyether segments are grafted onto the main chain of organosilicon heptamethyl trisiloxane at a molar ratio of 1:1.05 (n(Si-H):n(C=C)). To evidence product formation, the MPNTS were analyzed by FT-IR and1H NMR spectroscopy. The surface tension of NPNTS is 18.68 mN/m, and the CMC value is 78 mg/L by a contact angle tester. MPTNS shows hydrolytic stability and maintains that it could keep surface activity after standing for 60 days at pH = 7–10. The compatibility performance analysis shows that MPNTS has good compatibility and synergy with cationic, anionic, and nonionic surfactants, and it reveals the application prospects in daily chemicals, agricultural adjuvants, and other products.Keywords:silicone surfactant;trisiloxane;stability;synergy
研究领域:
化学
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材料科学
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表面活性剂技术
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产品关联
DOI
高影响因子
Journal of Macromolecular Science Part B-Physics
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2024
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IF 1.2
Jingwen Ren,Jipeng Dou,Long Zhang,Shan He,Yan Qin,Huadong Fu
This work mainly studied the influence of SiC and Si3N4 composite fillers on the ablation performance of silica/phenolic composites. The effect of Si3N4 content on the mechanical and ablative properties of the composites was investigated, and the bridging effect between the two different ceramic fillers was analyzed. The results indicated that the mechanical properties and ablation properties of the composite were improved due to the combined effect of the SiC and Si3N4. When the content of Si3N4 was 36phr, the flexural strength at room temperature was 114.6 MPa, the flexural strength after 1200 °C treatment was 18.38 MPa, and the linear ablation rate was 0.011 mm/s in the 1600 °C oxyacetylene ablation test for 30s, while the flexural strength without Si3N4 at room temperature was 105.4 MPa, the flexural strength after 1200 °C treatment was 10.35 MPa, and linear ablation rate was 0.061 mm/s in the 1600 °C oxyacetylene ablation test for 30s. The bridges between the Si3N4 and SiC ceramic fillers can form SiO2, SiCN and Si2N2O in the high temperature environment, which helps fill the pores on the surface of the composite, forming an effective protective layer structure and improving the high temperature and erosion resistance of the composites.
研究领域:
材料科学
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复合材料
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高温材料
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陶瓷填料
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DOI
高影响因子
LANGMUIR
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2019
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IF 3.683
Quanyi Yin,Shuhua Tu,Min Chen,Limin Wu
The fabrication of hollow organosilica nanoparticles with high elasticity is greatly desirable but still challenging. Herein, we present a new and simple strategy to prepare such nanoparticles by using hyperbranched polyvinylpolytrimethoxysilane (PVPMS) via a soap-free oil in water (O/W) emulsion system. PVPMS was synthesized through the radical polymerization of vinyltrimethoxysilane (VMS) followed by the acid-catalyzed hydrolytic polycondensation of trimethoxysilyl groups, which works not only as an organosilica precursor but also as a sole emulsion stabilizer due to its hydrolysis-induced amphiphilicity at the oil/water interface. When styrene was used as the oil phase and initiated to polymerize, hybrid polystyrene (PS) core–organosilica shell (PS@organosilica) nanoparticles were obtained by controlling the reaction conditions. Furthermore, highly elastic hollow organosilica nanospheres with low Young’s modulus (∼220 MPa) were yielded through solvent etching of the core. This study expands the scope of organosilica precursor from small molecule organosilane to polymeric macromolecule and provides useful guidance for application in other polyorganosilsesquioxane related hybrid organosilica particles and functional hollow nanoparticles.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
Journal of the American Chemical Society
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2024
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IF 14.4
Xuannuo Yi,Shasha Liu,Taotao Zhao,Xiangke Guo,Kai Zhou,Weiping Ding,Wei Wang
Zeolites are essential solid acid catalysts in various chemical processes. Temperature-programmed desorption (TPD) is one of the most established techniques used to characterize the acidity of zeolites by measuring the desorption kinetics of probes from bulk samples. However, conventional TPD can hardly deliver the intrinsic acid properties of zeolites because the apparent desorption kinetics are inevitably mixed with mass transfer and thermal conduction due to the large sample amount (∼0.1 g). Herein, we developed an optical microscopy approach to measure the TPD spectra of single zeolite nanoparticles, termed oTPD, by in situ monitoring of the reduced scattering intensity of individuals as a result of the desorption of probe molecules during heating. A significantly reduced sample amount contributed to the oTPD spectrum, revealing an intrinsic desorption temperature of ∼300 °C lower than the apparent value and also a greatly narrowed peak width from ∼150 to ∼15 °C. Correlating oTPD and micro-Raman spectra of the very same individuals further uncovered a linear dependence between the acidity and the content of silicon islands. This study provided unprecedented capabilities for measuring the intrinsic acid properties and the desorption kinetics of single zeolite nanoparticles, with implications for better understanding the structure–acidity relationship and for designing better zeolite catalysts.
研究领域:
化学工程
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催化科学
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产品关联
DOI
PubMed
高影响因子
MATERIALS CHARACTERIZATION
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2021
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IF 4.342
Wennan Su,Xiufang Cui,Guo Jin,Yajie Guan,Yao Zhao,Simin Wan,Changhao Liu,Yuyun Yang,Haoliang Tian
NiTi, NiTi-4Si, and NiTi-4Si-2YF 3 coatings were prepared on Ti-6Al-4V substrate by laser cladding to obtain composite multilayer protective coating for composite structure. The effects of Si and YF 3 addition on the microstructure, phase composition, microhardness , and phase transformation of the coatings were systematically analyzed. The coatings are mainly composed of NiTi, NiTi 2, and TiN phases. The addition of YF 3 results in the decrease of the dendrite TiN phase in the coating. TEM results show that the core-shell structure is observed in NiTi-4Si coating. The β -Ti phase was surrounded by the shell NiTi 2 phase. After the addition of YF 3 , the core-shell structure was found to disappear. With the addition of the Si element, the eutectic structure was found in the coatings. The eutectic structure is mainly composed of NiTi (B2) and Ti 2 Si phases. According to the SEAD result, there are crystallographic orientation relationships (ORs) between NiTi (B2) phase and Ti 2 Si phase as follows: 1 ¯ 11 B 2 / / 1 ¯ 23 Ti 2 Si . The average microhardness of the NiTi, NiTi-4Si and NiTi-4Si-2YF 3 coatings were at 468.33 HV 0.5 , 499.86 HV 0.5 , and 433.65 HV 0.5 , respectively. At the same time, the uniformity of the NiTi phase in NiTi-4Si-2YF 3 coatings is improved, which is conducive to a more complete phase transition.
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
高影响因子
TRIBOLOGY INTERNATIONAL
·
2024
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IF 6.1
Mohan Li,Shupei Liu,Mingmei Cao,Zheng Zhou,Jinsong Rao,Yuxin Zhang
In this study, fluorosilane-modified hollow mesoporous Diatom biosilica oil-carrying microcapsules (Oil@HMSNs/DE-F) were successfully synthesized using diatomite as hard-template, and dimethylsiloxane oil and hollow mesoporous silica as the core materials. Such microcapsules exhibited high oil-carrying capacity (41 %) and oil-carrying stability, which significantly higher than the Oil@DE-F microcapsules (33 %) (Comparison). Tribological tests showed that the Oil@HMSNs/DE-F composite coatings have excellent tribological properties and mechanical properties. Amazingly, 6 wt% Oil@HMSNs/DE-F epoxy composites coatings reduced the coefficient of friction by 79.9 % and the wear rate by 98.1 % compared to pure epoxy.
研究领域:
材料科学
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生物学
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 17
·2126-2133
·
IF 4.76
Jinfeng Shi,Na Zhao,Shuang Xia,Shaofeng Liu,Zhibo Li
Polysiloxanes containing phenyl functional groups are a class of promising polymer materials with enhanced low-temperature flexibility, high-temperature stability and great damping properties. In this context, organic cyclic trimeric phosphazene bases (CTPBs) have been proved to be highly efficient for the ring-opening polymerization (ROP) of octamethylcyclotetrasiloxane (D4) and the copolymerization of D4 with octaphenylcyclotetrasiloxane (P4) under mild conditions. The polymerizations are fast and the resulting polymers have high molecular weights (Mn up to 1353 kg mol−1). The molecular structures of the obtained copolysiloxanes were characterized by 1H NMR and 29Si NMR, which demonstrate that as high as 64 mol% diphenyl siloxane units can be incorporated within the copolysiloxane chain. Remarkably, copolysiloxanes with different contents of the diphenyl siloxane group are found free of T-branches and Q-branches based on the 29Si NMR analysis, indicating a good controlled ROP by the current organocatalytic system. DSC analysis shows no crystallization exotherm or melting endotherm in the range of −70 °C to 50 °C for all the copolysiloxanes, confirming that incorporation of diphenyl groups successfully suppresses the undesirable crystallization of polydimethylsiloxane. Moreover, the thermal stability of copolysiloxanes was evaluated by TGA, showing dramatically enhanced thermal stability with the increment of the diphenyl siloxane content.
研究领域:
材料科学
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有机化学
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产品关联
DOI
高影响因子
Materials Today Communications
·
2024
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IF 3.7
Yuqi Zhang,Zimu Zhang,Weixuan Chen,Xiang Zhang,Zisheng Guan
To enhance the performance of lithium-ion battery anodes, this study leverages recycled diamond wire-cut silicon particles, a byproduct of the photovoltaic sector. These particles undergo purification through acid wash and pyrolysis to eliminate contaminants, thereby serving as potential anode materials . The inherent challenge with silicon involves its significant volumetric expansion during lithiation and delithiation , which hampers its viability for commercial applications. Addressing this, the research introduces a facile approach by synthesizing porous silicon (pSi) via the Ag-assisted chemical etching method. Subsequently, a distinctive yolk-shell porous silicon@void@carbon (pSi@V@C) structure is created using a sacrificial template approach, ensuring the formation of voids between the porous silicon core and the carbon shell. This configuration mitigates the detrimental effects of silicon's volume expansion while enhancing electrical conductivity through the carbon shell. The pSi@V@C composite exhibits promising electrochemical performance, demonstrated by an initial discharge capacity of 1826 mAh g -1 and a Coulombic efficiency of 68.6% at 0.1 A g -1 . Remarkably, it maintains a capacity of 821.8 mAh g -1 after 550 cycles at 1 A g -1 , with a retention rate of 90.4%.
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Yan Liu,Qian Jiang,Ke Zhou,Qilin Gu,Zhaoxiang Zhong,Wenheng Jing,Yiqun Fan,Weihong Xing
The combustion efficiency of diesel can be significantly improved in the form of emulsion, contributing to the reduced emission of nitrogen oxides. It is thus worthwhile to develop an energy-efficient way to prepare stable diesel emulsions with uniform droplet size. Ceramic membranes with hydrophobic surface are highly desirable for high-efficient membrane emulsification process. We proposed a novel and straightforward approach of immersing silicon carbide (SiC) membrane into hydrophobic silica solutions obtained by co-hydrolysis to tailoring hydrophobic SiO 2 /SiC membranes. The effects of methyltriethoxysilane addition and aging days on the hydrophobicity of these silica particles were systematically investigated. Then, the deposition of silica particles on the SiC substrates was further controlled by regulating the dipping duration and dipping times. The membranes (M2-SiO 2 /SiC) prepared with 240 s and dipping 4 times showed an increased contact angle (136°), mean pore size of 0.4 μm, open porosity of 30 %, and pure water permeance of ∼ 1500 L·m −2 ·h −1 ·bar −1 . Moreover, the modified membranes were demonstrated to be mechanically stable. Furthermore, monodisperse diesel emulsions with an average droplet size of 2.1 μm and droplet size distribution of 0.61 can be generated by using the optimized M2-SiO 2 /SiC membranes at high emulsifying flux (1910 L·m −2 ·h −1 ). This work proposed an efficient strategy to simultaneously optimize the surface wettability and pore structure of ceramic membranes, satisfactorily for membrane emulsification applications with high efficiency.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Longpeng Zhou,Hongtao Liu,Aowei Liu,Lizao Zhou,Chunchun Du,Yaru Li
Ice accretion has adverse effects on outdoor equipment, and slippery liquid-infused surface has attracted increasing attention due to its low ice adhesion strength ( τ ice ) and great potential in practical application. However, the surface lubricant loss leads to the failure of icephobicity in this system. In this paper, the icephobic surface with external and self-replenishing properties (RDLS) is prepared to enhance anti-icing and deicing properties by the facile method with infusing the silicone oil and fumed silica into the epoxy resin adhesive. As an outcome, the prepared RDLS exhibit anti-icing and deicing properties, and it also shows mechanical durability. Meanwhile, the use of fumed silica is proposed to act as a reservoir for silicone oil to extend the lifetime of oil-releasing properties. The icephobicity of the coating can also be improved by the proper amount of fumed silica. Furthermore, obtained RDLS showed superior sustainability, and the silicone oil in the coating can be replenished easily. The problem of icephobic failure caused by lubricant loss is solved effectively. This work provides a new and facile way to fabricate an icephobic coating with external and self-replenishing properties.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）