KEY ENGINEERING MATERIALS
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2023
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IF 0
Xing Xing Wang,Guan Cheng Jiang,Guo Shuai Wang,Li Li Yang,Yin Bo He,Xiao Ya Wu
In South China Sea, the natural gas hydrates are usually reserved in argillaceous siltstones. These argillaceous siltstones are weakly cemented and incorporated with the solid hydrates. During the drilling process, the natural gas hydrates may decompose unexpectedly, resulting in the wellbore collapse. To improve the stability of the wellbore, this study develops a wellbore strengthener for water-based drilling fluids used in argillaceous siltstones. Tannic acid/polyvinyl (TA/PVA) alcohol has been adopted for preparing the wellbore stabilizer. A series of experiments have been conducted to investigate the effects of newly developed wellbore strengthener on the mechanical properties of the argillaceous siltstones as well as its mechanisms on the wellbore stability. The experimental results show that the wellbore strengthener developed in this study can significantly improve the compressive strengths of the argillaceous siltstone cores. The AFM characterizations indicate that the adhesion force between the silica (the major compound in argillaceous siltstones) microspheres and the wellbore strengthener can reach up to 2138 nN. Moreover, the SEM images visually show good cementation of the argillaceous siltstones after being treated by the wellbore strengthener. In addition, the wellbore strengthener can also assist in reducing the fluid losses of water-based drilling fluids. It is hopeful that the wellbore strengthener provided in this study help the development of underwater natural gas hydrates.
研究领域:
石油工程
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材料科学
✓ 已验证
DOI
SOLID STATE PHENOMENA
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2022
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IF 0
Xiao Ying Yan,Guo Bao Zhang,Rong Hui Yuan,Xiang Yu Ye,Xi Xi Chen,Hui Hui He
We reported a facile solvothermal approach to synthesize C/N-doped TiO2 (C/N-T) using a template-free method. The morphology and composition of the C/N-T were evaluated by transmission electron microscopy, X-ray diffraction, wavelength dispersive spectroscopy and X-ray photoelectron spectroscopy. The photodegradation of formaldehyde was studied in environmental chambers under specific conditions combined with UV-Vis determinations. The catalytic oxidations of C/N-T nanoparticles were characterized by degrading formaldehyde of plywood, which was induced via visible-light illumination. A maximum 95.7% of degradation efficiency within 55 min showed enhanced photocatalytic activity.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
KEY ENGINEERING MATERIALS
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2023
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IF 0
Yu Hong Ma
The employment of lithium (Li) metal is crucial to sustainable Li metal batteries (LMBs) with realistically high energy density. The management and usage of Li in reality, however, remain high challenge due to the desirable of obtaining an undamaged Li structure arising from the indispensable in extenuating strongly environmental dependence of Li during stored procedure and minimizing the Li depletion and pulverization on long-term cycles. Herein, we impair the molecular hydrogen bonding cooperation between lithium and water molecules on the surface of Li to demonstrate an achievement of environmental independent and durable Li via integrating a reinforced molecular hydrophobic interface on the surface of Li. As a result, the molecular hydrophobic interface modified Li metal can exhibit dendrite-free Li deposition and achieve stable operation for 200 cycles in Li-S full cell at a current of 1 C.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
DOI
KEY ENGINEERING MATERIALS
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2022
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IF 0
Shuai Ren,Xiao Hua Lv,Guo Feng Liu,Xiao Yuan Zhang
Insulators covered with superhydrophobic coatings have better anti-pollution flashover performance. In high-pollution areas, the superhydrophobic coating gets covered with a contamination layer. The droplets are in contact with the contamination layer instead of the superhydrophobic coating. However, there is still a lack of relevant research on the hydrophobicity of the contamination layer. It is not conducive to evaluating the functional performance of superhydrophobic insulators in high-pollution areas. Choose diatomite to simulate contamination. The effects of fouling time, environment temperature, diatomite density, and impurity (NaCl) on the hydrophobicity of the contamination layer are analyzed experimentally. The experiment results show that the diatomite layer becomes hydrophobic over time. The higher the temperature is, the faster the hydrophobicity of the contamination layer will increase, and the higher the peak value of the static contact angle will be. However, the diatomite density and the exitance of NaCl have little influence on the hydrophobicity of the diatomite layer. Furtherly, the composition of the superhydrophobic coating is found in the diatomite layer, which proves the existence of hydrophobicity transfer. According to theoretical analysis, the appearance of transfer will enhance the hydrophobicity of diatomite particles. When the angular coordinate of the liquid-protrusions-gas triple line is greater than 90°, the mechanical conditions for the diatomite particles carried away by the droplet can be satisfied. As a result, hydrophobic diatomite is attached to the droplets’ surface.
研究领域:
电气工程
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材料科学
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环境科学
✓ 已验证
DOI
Nano Hybrids and Composites
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2023
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IF 0.4
Yan Hua Lu,Min Min Xu,Chen Jie Zhang,Ya Xian Yuan,Jian Lin Yao
The rapid recombination of carriers on plasmon metal nanoparticles leads to relatively low efficiency of traditional photocatalysts. The combination of a metal and a semiconductor allows to the separation of hot electrons and holes to improve photocatalytic efficiency. In this study, Au nanoparticles were integrated with semiconductor TiO2 nanoparticles of different sizes to improve the photocatalytic activity. Various techniques have been developed to study the mechanism of catalytic activity, the significance of band bending in the space-charge region within metal–semiconductor nanocomposites, and the built-in electric field. The results provide theoretical and experimental evidence for the design of a high-performance surface plasmon resonance (SPR) photocatalyst. To reveal the interface band structure, surface-enhanced Raman spectroscopy (SERS) was employed to analyze the band structure of the TiO2–metal composites. This approach was based on the electrochemical Stark effect and a molecular probe strategy, combined with X-ray photoelectron spectroscopy (XPS), Electrochemical impedance spectroscopy (EIS), and other techniques at the molecular level. The results demonstrated that charge transfer occurred spontaneously between the Au nanoparticles and TiO2, and that the TiO2–metal interface constitutes a Schottky barrier. Moreover, the size of the TiO2 nanoparticles affects the degree of band bending. Optimal state matching was achieved with TiO2 (60 nm)–Au, improving the photocatalytic activity of the nanocomposite. The photocatalytic coupling reaction of p-aminothiophenol (PATP) acted as a probe to study the catalytic performance of TiO2–metal nanocomposites. The results revealed that the introduction of TiO2 improves the SPR catalytic activity of Au, mainly through the efficient separation of electrons and holes at the TiO2–metal interface.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Nano Research
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2022
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IF 1.78
Rusul Mohammed Abdallah,Raad M.S. Al-Haddad
There are many methods for synthesizing magnetite nanoparticles. Most methods take a long time, and the result is undesirable. In this paper a green method was used to synthesize nanoparticles because it takes a short time and is both straightforward and eco-friendly. It is done by adding : =1:2 molar ratio solution with different amounts of extract and different amounts of NaOH solution for 20 min at different temperatures, in hotplate stirrers, to control their relative size. UV-Vis spectroscopy, vibrating sample magnetometer technique (VSM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to characterize the magnetite nanoparticles. The result confirms that the changes in amounts of NaOH and extract led to a change in the pH of a solution and that the increase in amounts of the extract caused the low addition of NaOH. These changes influenced the process of synthesis and characterization. The Uv-vis analysis confirms that the surface plasmon resonance had a highly visible brad peak in the 290–460 nm range, as well as a peak shift to shorter wavelengths (blue shift) with a pH change and a peak shift to longer wavelengths (red shift) with a temperature change. TEM imaging confirms that all the synthesized had a spherical shape with size changed according to a parameter change of within 40–9 nm. Magnetic analysis showed the magnetite nanoparticles synthesized have smaller sizes and are superparamagnetic with the influence of particle size on the magnetic properties, including Hc, Ms, and Mr.
研究领域:
材料科学
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纳米技术
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化学
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物理学
✓ 已验证
DOI
高影响因子
Nano Hybrids and Composites
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2022
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IF 0
Yue Zhang,Tao Li,Shi Yu Tang,Xin Yue Xie,Ru Zeng Liang,Xiao Xiao Chu
Increasing demands of microwave absorbents require new approaches to enhance the absorbing performance. Metal−organic frameworks (MOFs) could be developed as effective absorbers owing to their outstanding features including intrinsic porosity and high specific area. Herein, novel nanostructured Co-MOF-74 composites have been successfully fabricated via a simple solvothermal method. Excellent absorption performance was achieved for the composite with a minimum reflection loss (RL) of −25.5 dB at 2.5 mm and a broad absorption bandwidth (RL < −10 dB) of 6.7 GHz. Such absorber could be developed as lightweight and high-efficiency absorbing materials, and this work provides inspiration for the design of advanced absorbers with strong dissipation capacity and broad effective bandwidth.
研究领域:
材料科学
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电磁工程
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纳米技术
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
·
2022
·
IF 0
Mohd Khairul Nizam,Mohamad Shafiq Mohd Razmi,Najmuddin Mohd Ramli,Mohd Najib Razali
Three formulations intended for NSF H1 food-grade grease were prepared in this study comprising paraffin oil as a base oil and fumed silica as a thickener. No additive was added in formulation 1 (F1) and formulation 2 (F2), whereas chitosan was added in formulation 3 (F3) as an additive. A commercial food-grade grease (FGG) was used for comparison purposes. The formulated greases and the commercial FGG were characterised for thermal stability via thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (DTG). Fourier-transform infrared (FTIR) spectroscopy, dropping point, oil separation, and consistency tests were also carried out to evaluate the properties of the greases. The FTIR spectra were obtained for the fresh and aged greases for grease characterisation. The results showed that the grease made with chitosan as an additive demonstrated higher oil separation, better consistency, and was less affected by ageing, as indicated by the change of grease colour after the oil separation test. F1, F2, F3, and the commercial FGG recorded dropping points higher than 350 °C, indicating no dropping point properties for the tested greases. The grease formulated with chitosan (F3) achieved the highest oil separation with 1.21%, while the commercial FGG recorded the lowest oil separation with 0.66%, followed by F1 and F3 with the oil separation of 0.99% and 0.98%, respectively. For the consistency test, the NLGI number for each formulation varied but the commercial FGG showed the lowest NLGI number of 2, whereas F3 showed the NLGI number in the range of 2–3, and F1 showed the NLGI number of 3. The aged grease of F3 had unchanged consistency after the oil separation test. Based on the results, the formulated greases have acceptable properties in comparison to the commercial FGG, and the addition of chitosan contributes positively to the grease characteristics.
研究领域:
材料科学
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食品技术
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润滑工程
✓ 已验证
DOI
Journal of Nano Research
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2023
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IF 1.7
Yong Qiang Dang,Xiang Yu Feng,Bo Ni Li,Rui Huang,Jia Jia,Jian Lan Zhang,Ya Ting Zhang
Photocatalytic CO2 reduction to solar fuel is a potential way to overcome the problem of high carbon dioxide concentrations; however, the process still faces enormous challenges, such as the low light absorption efficiency and high carrier recombination rates. This work synthesized tetraphenylporphyrin-based carbon dots (TPP-CDs) for the photocatalytic CO2 reduction to CH3OH under simulated sunlight to extend the absorption region of the CDs. The conduction band of the TPP-CDs has a sufficiently negative reduction potential to reduce CO2. TPP-CDs containing 1 wt.% TPP achieved an optimum CH3OH production rate of 173.35 μmol·gcat-1·h-1, with a remarkable 2.06-fold increase compared to pristine CDs without TPP. In this study, TPP-CDs were synthesized by changing the CD precursors to improve the utilization of visible light and apply them to the photocatalytic reduction of CO2.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE FORUM
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2022
·
IF 0
Yu Tong Han,Da Gang Li,Kang Jie Shi,Dan Ma,Yu Tang,Chao Qun Ma
In the context of carbon neutrality, it is of good economic and ecological value to replace synthetic fibres with natural fibres as reinforcing materials in the preparation of composites. The effect of the hot pressing process parameters on the physical and mechanical properties of the LBF/PP composites was further investigated. The distribution of LBF in the composites was observed by CT. The experimental results show that the hemicellulose content of the BF decreases and the lignin content decreases after the alkali treatment. The mechanical properties of the LBF/PP composites were better at a hot pressing temperature of 180°C, a hot pressing pressure of 8 MPa, a hot pressing time of 15 min and a mass fraction of 70% LBF, with bending strength and bending modulus reaching 226.1 MPa and 15.1 GPa respectively. CT results show that the fibres are evenly distributed in the composites and that the hot pressing process allows the molten PP to penetrate the pores of the LBF surface, forming a good physical and mechanical bond. These composites can be used in various applications such as construction, automotive, consumer goods etc. They are considered to be a suitable alternative to solid plastic products and materials.
研究领域:
材料科学
·
生态学
✓ 已验证
DOI
Journal of Nano Research
·
2024
·
IF 0.8
Hong Wu Zhu,Yu Song Pan,Yuan Qing Wang,Yan Lei Xiang,Rong Han,Run Huang
Photocatalytic technology is one of the promising technologies for wastewater treatment. Herein, zinc oxide/multi-walled carbon nanotubes (ZnO/CNTs) photocatalyst was successfully prepared by hydrothermal method with combining in-situ synthesis technology. The micro-morphology, crystalline structure, surface chemical elements, and optical properties were characterized by SEM, TEM, XRD, FTIR, UV-Vis, and DRS technologies. The ZnO/CNTs photo-catalyst exhibited enhancement photo activity for degradation of organic pollutants under simulated light irradiation. Specifically, the photo-catalytic activity of the ZnO/CNTs catalysts improved with the rise of CNTs content in the composites. Investigation on the photo-degradation mechanism verified that the presence of CNTs in the catalyst not only optimized the band structure of ZnO semiconductor but also contributed to the transfer of photo-generated electrons and reducing the recombination of electron-hole pairs due to its excellent conductivity. Moreover, the active radical groups such as superoxide radical (O-2), hole (h+), and hydroxyl radical (·OH) played the dominated role for the pollutants degradation under the simulated sunlight irradiation. In addition, ZCT20 catalysts and light irradiation had synergistic effects on antibacterial activity, whose antibacterial rates against E. coli and S. aureus were up to 99.96% and 99.94%, respectively. Investigation on antibacterial mechanisms revealed that the existence of ROS and the continuous release of Zn2+ played an important role for improving the antibacterial activity of the ZCT20 catalyst under the simulated sunlight irradiation.
研究领域:
环境科学
·
材料科学
·
微生物学
✓ 已验证
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2022
·
IF 0
Shariena Shamsul Bahari,Yuen Mei Lian,Ros Azlinawati Ramli,Lee Siew Ling
Textile dyeing often employs reactive dyes. The dye wastewater contains hazardous materials and is toxic to humans and the environment. Photodegradation using a semiconductor photocatalyst is a promising alternative approach for water purification and wastewater treatment. However, the photocatalyst’s low adsorption ability is a problem in the photocatalysis process. To compensate for this shortcoming, photocatalyst content must be combined with an adsorbent. Raw corn cob and titanium dioxide (TiO2) were used in this photocatalysis. Due to a synergistic impact, raw corn cob’s ability to adsorb and titanium dioxide’s ability to photodegrade organic pollutants from water bodies is expected to boost the removal performance. The degradation of Reactive Blue 4 (RB4) as a targeted dye was carried out in this research using a suspended mixture of commercial anatase TiO2 and raw corn cob under UV light. The effect of initial pH solution, initial dye concentration and contact time, TiO2-corn cob dosages, and the influence of other pollutants were investigated as factors influencing photodegradation-adsorption of RB4. The high removal rate of RB4 was obtained at a low pH of 2 and RB4 concentration of 40 ppm. The increased dose of TiO2-corn cob improved the RB4 dye removal performance. In conclusion, combining photodegradation and adsorption systems as a hybrid treatment method resulted in a synergistic increase in the efficiency of RB4 removal.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
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