APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Jiao Xie,Jia Hu,Xudong Lin,Liang Fang,Fang Wu,Xiaoling Liao,Haijun Luo,Liuting Shi
In this work, micro-nanostructure polydimethylsiloxane/silicon dioxide (PDMS/SiO 2 ) composite coatings were fabricated on the surface of magnesium alloys with two different sizes of SiO 2 nanoparticles by a simple painting method. The effects of the proportion of 40 nm and 50–250 nm SiO 2 on the wettability, wear and corrosion performance of the composite coatings were investigated. The morphology, composition, water contact angles (WCAs), wear and corrosion resistance of the composite coatings were measured by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), the contact angle meter, sandpaper-weight device and electrochemical workstation, respectively. And the mechanical and thermal stability were also respectively obtained by finger-wipe, knife-scratch tests and thermogravimetry. It is found that the PDMS/SiO 2 composite coatings fabricated under optimized parameters are stable and superhydrophobic (SH) ones and their WCAs can maintain at a high level (138°–150° and 133°–153°) under 50 abrasion cycles with sandpaper. The composite coatings exhibit good resistance to knife damaging and finger touching. The electrochemical experiments show that the robust coatings can significantly improve the corrosion resistance of magnesium alloys. It is rationally expected that the results can provide an informative reference to the fabrication of wear-resistant super-hydrophobic composites on magnesium alloys.
研究领域:
材料科学
·
表面工程
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DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2021
·
IF 8.528
Baojie Zhang,Zongwei Tong,Yifan Pang,Hui Xu,Xiaolei Li,Huiming Ji
Thermal insulation materials play an important role in energy conservation and the sustainable development of natural resources. Herein, novel silica composite nanofibers (SiO 2 NFs) with closed cell structure and excellent thermal insulation performance were designed and prepared via electrospinning technique using hollow SiO 2 /TiO 2 spheres (HSTSs) as pore-forming agent and infrared shielding agent. The addition of HSTSs broke the continuity of heat transfer pathways inside the NFs and enhanced the infrared thermal radiation shielding performance of SiO 2 NFs, endowed it with ultra-low thermal conductivity and low infrared transmittance. Meanwhile, the materials exhibited good flexibility, high tensile strength , low density and excellent thermal stability, indicating promising application as insulation materials. This research not only provides a novel strategy to prepare porous nanocomposite fibers for thermal insulation, but also offers a new insight for the development of porous materials with multiple functions.
研究领域:
材料科学
·
能源工程
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Yangxian Ou,Tao Zhang,Li Lv,Wenxiang Tang,Shengwei Tang
CO 2 hydrogenation is one of the reactions to realize effective utilization of CO 2 , while Cu-Zn based catalyst is widely adopted for CO 2 hydrogenation to value-added chemicals like methanol. However, this process is less efficient since the poor performance of catalyst due to its poor dispersion or sintering issue. In this study, three kinds of SiO 2 supports (SBA-15, MCM-41 and Nano-SiO 2 ) with different porous structure were conducted to load same amount of 5.0 wt% Cu-ZnO active component (the molar ratio of Cu/Zn is 2.0), which were further applied for CO 2 hydrogenation. All catalysts were characterized chemically, morphologically and structurally by different techniques such as XRD , BET, TEM , H 2 -TPR and CO 2 -TPD. The results showed that the structure of three catalysts was basically preserved and the surface aera kept stable after loading active component, while the active component had the best dispersion when SBA-15 was used as the support and space-time yield of methanol is about 705.6 g MeOH •kg Cu −1 •h −1 ,which is higher than that of Nano-SiO 2 -5% (532.9 g MeOH •kg Cu −1 •h −1 ) and MCM-41–5% (213.2 g MeOH •kg Cu −1 •h −1 ). Due to the confined effect of mesoporous channel structure provided by SBA-15 support, the Cu-Zn interaction could be significantly enhanced with increasement of medium and strong alkaline sites, further improving CO 2 activation ability. This work provides a useful strategy to improve the catalytic efficiency of classical Cu-Zn catalyst for the CO 2 hydrogenation process.
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高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Chaofeng Lv,Jincui Ren,Yuting Duan,Yisheng Wu,Xinyi Li
To improve the oxidation resistance of alumina–carbon refractories, SiO 2 –B 4 C-glass composite coating was prepared by slurry brushing method on the surface of refractories. Effect of SiO 2 content on the oxidation resistance of the coating was studied. Oxidation resistance mechanism and failure reason of the SiO 2 –B 4 C-glass coating were discussed. Results showed that introducing SiO 2 could increase viscosity activation energy and elevate the glass layer's viscosity at high temperature. With the increase of SiO 2 content, the glass viscosity at high temperature gradually increased. When SiO 2 content was too low, the glass exhibited smaller viscosity and larger fluidity, so the glass layer was easy to be washed away. When SiO 2 content was too high, the glass phase with high viscosity and low fluidity could not uniformly cover on the surface of alumina–carbon refractories. The composite coating with SiO 2 content of 55 wt% exhibited excellent oxidation resistance, which could effectively protect alumina–carbon refractories at 800 °C for 100 h with weight loss of only −1.721%. Excellent oxidation resistance of the coating mainly depended on the glass layer with good self-healing ability. With the extension of oxidation time, the coating thickness decreased, leading to the relatively poor self-healing ability and reduced weight gain rate of the coating.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2018
·
IF 3.306
Li-Zhi Zhang,Qian-Wen Su
Membranes of low thermal conductivity (thermal insulation) but high moisture permeability are highly desired in membrane-based humidification-dehumidification (MHDD) seawater desalination technology. The porous membranes with thermal insulation could decrease the heat losses in humidification, thus the system energy performance can be improved. To satisfy this purpose, in this study, a PVDF/SiO 2 (Si aerogel) composite bilayer membrane of low heat conductivity is prepared and analyzed. To solve the problem of cracking in forming SiO 2 layer, the casting solution (TEOS, H 2 O) is doped with a drying control chemical additive (DCCA) N, N -dimethylformamide (DMF) to decrease the surface tensions in the gel. Then performance analysis of the developed membranes are conducted and the membranes are characterized. The results found that the heat conductivity is decreased from 0.08199 W m −1 K −1 to 0.04487 W m −1 K −1 , with a penalty of effective moisture diffusivity sacrificed from 4.93 × 10 −6 m 2 /s to 2.42 × 10 −6 m 2 /s. They are superior to the available SiO 2 blend insulation membranes. Further, the membranes can be optimized by facile structural manipulations such as adjusting the SiO 2 layer thickness to realize the desired performance while balancing the paradox between the permeability and heat conductivity. This is the first time that heat conductivity of membranes can be manipulated for seawater desalination.
研究领域:
材料科学
·
环境工程
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DOI
高影响因子
POWDER TECHNOLOGY
·
2019
·
IF 3.413
Xuechen Tang,Wanli Kang,Bobo Zhou,Yongbo Gao,Changxiao Cao,Shujun Guo,Muhammad Wassem Iqbal,Hongbin Yang
Polymer/nano-SiO 2 composite microspheres (PNSCMs) were synthesized via inverse suspension polymerization with 3-methacryloxypropyltrimethoxysilane (MPS) modified SiO 2 as the reinforcing filler. The influences of these polymerizable nanoparticles on the swelling behavior, mechanical property, thermal stability, viscoelasticity and dispersion stability were examined in detail. Moreover, the plugging behaviors were investigated by sand pack tests. The results indicate that the introduction of these modified nanoparticles revealed a significant enhancement on the comprehensive properties of PNSCMs. By varying the content of MPS-modified SiO 2 , the environmental sensitivity of the microspheres’ swelling behavior was reduced. Besides, the mechanical property, thermal stability and viscoelasticity were greatly improved by increasing the SiO 2 loading. Compared with SiO 2 -free ones, PNSCMs exhibited better dispersion stability and plugging performance, and the maximum plugging rate reached 93.64%, which was increased by 14.69%. These PNSCMs studied can realize in-depth profile control in reservoirs and have great application prospects in the further enhanced oil recovery research.
研究领域:
石油工程
·
材料科学
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DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Lele Jin,Wenzhi Li,Qiying Liu,Longlong Ma,Song Li,Yang Liu,Baikai Zhang,Qi Zhang
The liquid fuel (made of C 5 /C 6 alkanes) was obtained directly from the hydrogenolysis of microcrystalline cellulose (MCC) with Ir-VO x /SiO 2 combined with HZSM-5 as the composite catalyst in a biphasic system (n-dodecane + H 2 O). The performance of the catalyst was investigated by carrying out a series of experiments using various V/Ir molar ratios , catalyst dosages, reaction temperatures, reaction time, hydrogen pressure and substrates. At the optimized conditions, the cellulose was almost completely converted, and at the same time, a high C 5 /C 6 yield of 85.1% was obtained at 210 °C for 24 h and 6 MPa with the V/Ir molar ratio being 0.13. These results not only proved that Ir-VO x /SiO 2 (V/Ir = 0.13) has excellent performance for the hydrogenolysis of MCC to liquid alkanes, but also indicated that vanadium is a good metal promoter for iridium . In addition, it was proven the C5/C6 alkanes were obtained via sorbitol through the combined effect of Ir-VO x /SiO 2 and HZSM-5.
研究领域:
催化化学
·
可再生资源转化
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DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Zhengxin Li,Meichuan Liu,Lifang Fan,Hongyang Ke,Caifang Luo,Guohua Zhao
In this work, bi-functional SiO 2 -Pt@meso-SiO 2 core–shell nanoparticles were designed to prepare a highly sensitive and selective electrochemical zinc(II) aptasesnor. This core–shell structure boasts its SiO 2 mesoporous shell and the inside Pt nanoparticles. SiO 2 mesoporous shell can fix aptamer without affecting its configuration and can admit electrolyte through the shell. SiO 2 core inside can be the substrate of larger amount of Pt nanoparticles that improve the conductivity of the modified electrode dramatically. Due to the application of such a special bi-functional structure and the aptamer's strong combination capacity with Zn 2+ , Zn 2+ is pre-enriched onto the electrode effectively and specifically, so that it can be determined sensitively and selectively. Results have shown that the zinc(II) aptasensor can be utilized at a wide linear working range from 100 pM to 50 μM and a low detection limit of 65 pM, which makes it practical in both biological samples and environment monitoring. This method has been successfully applied in Zn 2+ monitoring in human blood and disrupted human cells (MCF-7).
研究领域:
分析化学
·
生物传感
·
环境监测
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DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Sheng Li,Chaoqi Zhao,Rui Zhang,Junjie Shi,Yuyan Wu,Xiao Zhang,Chuan Wang,Shizhuo Yin,Yandong Li,Jianzhong Li
The Ho 2 O 3 -Al 2 O 3 -SiO 2 system exhibits great application potential for advanced environmental barrier coatings and multifunctional materials, whereas critical high-temperature phase equilibrium data remain scarce. In this work, the 1600 °C isothermal section of the ternary system was systematically constructed using equilibration and quenching experiments, combined with X-ray diffractometry (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and differential scanning calorimetry (DSC). Crucially, the thermodynamic stability of the Ho 2 Si 2 O 7 phase at 1600 °C and above is confirmed, refining the previously reported Ho 2 O 3 -SiO 2 binary phase diagram. At 1600 °C, the Ho 2 O 3 -Al 2 O 3 -SiO 2 system comprises one liquid-phase region, eleven two-phase regions, and nine three-phase regions. The eutectic temperature of the system was measured to be 1359 °C, corresponding to the reaction L ⇋ SiO 2 + Ho 2 Si 3 O 9 + mullite. The solid-solution mechanisms were determined for the two phases Ho 9.33+2 x (Si 1- x Al x O 4 ) 6 O 2 ( x = 0-0.09) and Ho 4 Al 2(1- x ) Si 2 x O 9+ x ( x = 0-0.33). Comparison with FactSage 8.3 calculations reveals that current commercial databases exhibit significant deficiencies for the Ho 2 O 3 -SiO 2 binary system. This study further improves the thermodynamic database of rare-earth oxides. The findings not only provide key data for optimizing CALPHAD thermodynamic models, but also offer an important basis for the composition design and phase regulation of environmental barrier coatings intended for extreme environments.
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高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2023
·Vol. 109
·期 2
·523-533
·
IF 2.5
Hao Mingyuan,Chen Huanle,Xia Chenkang,Su Teng,Ma Chao,Miao Yang
Aluminum silicate nanofibers (ASNFs) have attracted significant attention due to their excellent stability and high-temperature properties. Al 2 O 3 -SiO 2 aerogel (ASAs) has high porosity and low thermal conductivity, but its mechanical properties need to be improved. Reinforcing aerogels with fibers can lead to remarkable enhancements in their properties. Reducing the fiber diameter has proven to be an effective means of improving the structural integrity and mechanical stability of aerogel composites. In the context of this study, we prepared aluminum silicate nanofibers (ASNFs) with a diameter of 170 nm through the utilization of electrostatic spinning. These ASNFs were then successfully integrated with aluminum silicate aerogels (ASAs) to create a novel composite material known as aluminum silicate nanofiber-reinforced Al 2 O 3 -SiO 2 aerogel (AS/ASNFAs). Its microstructure, mechanical properties and heat insulation properties have been researched. The results show that the compressive strength of AS/ASNFAs (0.44 MPa) is significantly higher than that of Al 2 O 3 -SiO 2 aerogel (0.16 MPa). Meanwhile, the AS/ASNFAs has high specific surface area (600 m 2 /g), low density (0.15 g/cm 3 ), and low thermal conductivity (0.026 W/(m·K)). This work provides a useful solution to improve the comprehensive properties of Al 2 O 3 –SiO 2 aerogel composites. Graphical
研究领域:
材料科学
·
纳米技术
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DOI
高影响因子
Journal of Analysis and Testing
·
2021
·Vol. 5
·期 1
·40-50
·
IF 0
Tan Xiao-Hong,Huang Guo-Bin,Cai Zhi-Xiong,Li Fei-Ming,Zhou Yan-Mei,Zhang Mao-Sheng
The application of all-inorganic CsPbX 3 (X = Cl − , Br − and I − ) perovskite nanocrystals (PNCs) is hindered by their poor stability under different environments (moisture, UV light and high temperature). Herein, we demonstrate a novel in-situ growth and post-coating technique to prepare monodisperse spherical sandwiched structured SiO 2 @CsPbX 3 @SiO 2 perovskite composites. In this strategy, the environmental stability of CsPbX 3 PNCs is remarkably improved due to protecting evenly distribution in the surface of composites through the design of spherical sandwiched structure, and the negative effects of SiO 2 coating on photoluminescence property of CsPbX 3 PNCs could be reduced effectively. Furthermore, regular monodisperse spherical structure and uniform size of composites greatly benefit their application in relative fields. The experiment results indicate that the as-prepared product have outstanding abilities of water-, oxidation- and UV radiation resistance. Finally, the SiO 2 @CsPbBr 3 @SiO 2 perovskite composites are successfully used for highly sensitive detection of Fe 3+ in water sample. The results show limit of detection (LOD) is 3 µM and good linearity is between 10 and 70 µM ( R 2 = 0.9963). Furthermore, the proposed perovskite composites have been successfully applied for the analysis of Fe 3+ in real samples with satisfactory results.
研究领域:
材料科学
·
分析化学
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DOI
Materials
·
2023
·Vol. 16
·期 9
·3532
·
IF 3.4
Ruohan Xia,Bing Zhang,Kousuo Dong,Yao Yan,Zisheng Guan
Superhydrophobic coatings with excellent water-repellent properties imply a wide range of application areas. However, improvements are needed in terms of stability and complex processing procedures. In the present study, a superhydrophobic coating on Al sheets was prepared by mixing hexadecyltrimethoxysilane (HDTMS)-modified SiO2nanoparticles and acid-catalyzed silica sols (HD-SiO2/SiO2Sol) with polydimethylsiloxane (PDMS) binder. The HD-SiO2nanoparticles and acid-catalyzed silica sol (SiO2sol) form a binary graded micro-nanostructure, providing excellent superhydrophobicity (Water Contact Angle = 158.5°, Sliding angle = 0°). Superhydrophobic coatings with excellent water-repellent properties have potential for corrosion prevention. However the commonly used organic resins have poor chemical and mechanical properties. In the present study, the results of outdoor exposure for 30 days, immersion in acid and alkaline solutions for 24 h, grit abrasion, and water impact experiments, respectively, showed that the prepared superhydrophobic coating has good wear resistance. The integrated superhydrophobic coating on the Al sheets exhibited good corrosion inhibition with an efficiency (η) of 98.9%, which is much higher than that of the uncoated sheets. The present study provides a promising approach for producing stable superhydrophobic coatings at a low cost, with the potential to supplant conventional organic resin anti-corrosion coatings.Keywords:superhydrophobic;SiO2;surface modification;anti-corrosion
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PubMed
高影响因子
危险品化学品经营许可证（带存储）