SOLID STATE PHENOMENA
·
2018
·
IF 0
Min Wang,Zi Yuan Wang,Ya Jie Yuan,Wei Pan
The 8 wt.% yttria-stabilized zirconia (8YSZ) thermal barrier coatings (TBCs) are widely used to protect hot superalloy components of gas turbine and jet engine. However, Cracks and pores in the 8YSZ coating would accelerate the oxidation of the bondcoat alloy and the corrosion of 8YSZ topcoat by molten salts and finally result in permanent failure of the TBCs. Hence, in this work, a sol-gel spin-coating method was employed to prepare a dense α-Al2O3 film on the surface of air-plasma-sprayed 8YSZ coatings, in order to block the paths of cracks and pores while keeping the stress tolerance of 8YSZ coatings. The influences of the polyvinylpyrrolidone (PVP) and alumina content of the sol on the microstructure of the α-Al2O3 film were investigated. It is found that a sol with PVP addition amount of 50 mg/mL and alumina solid content of 10% let to the achievement of a compact α-Al2O3 film. The positive results in this work would inspire more efforts to prepare dense films on TBCs and therefore improve their performance under service conditions.
研究领域:
材料科学
·
表面工程
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产品关联
DOI
JOURNAL OF MATERIALS SCIENCE
·
2025
·
IF 3.9
Zhao Hengyu,Wang Baoyu,Yang Shiqing,Zhu Huamiao,Zhang Zihao,Li Wenyao,Yang Xiangmin,Fang Bin,Liang Ying,Zhang Zhen
As conductive fillers, the uniformity and compactness of composite metal powders are crucial for preparing high-performance conductive pastes. In this study, a self-circulating electroplating method was proposed, which could efficiently deposit Sn plating on the seed of Cu micro-flakes to prepare composite metal powders. The effects of total electroplating time, single electroplating time, loading mass of Cu seeds on the cathode support, and the bath temperature on Sn plating layer have been systematically investigated and optimized. And the influence mechanisms of electroplating parameters on coating coverage, compactness, and uniformity of Sn plating layer were proposed. The Sn-coated Cu micro-flakes with compact plating layer of 142.9 nm thickness were obtained with the total electroplating time of 60 min, the single electroplating time of 3 min, and the loading mass of Cu seeds of 18 mg/cm 2 at the bath temperature of 15 °C. Finally, the as-prepared Sn-coated Cu micro-flakes were used as fillers to prepare conductive pastes, which exhibited good antioxidation performance at 85℃ and 85%R.H. Graphical abstract
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DOI
高影响因子
Corrosion Communications
·
2024
·
IF 0
Zhiyuan Feng,Jiao Li,Keqi Huang,Guoqiang Liu,Huanhuan Bai,Xin Huang,Jun Qi,Zhengwei Tang,Penghai Xu,Xiaofei Yang,Zheng Qu,Guozhe Meng
Within the realm of corrosion protection methods for Al alloys, sol-gel technique has garnered increasing attention. However, conventional sol-gel methodologies cannot provide adequate long-lasting corrosion protection to Al alloys when exposed to chloride-rich solutions. This paper introduces an innovative approach to substantially augment the corrosion resistance of aluminum alloys through utilization of polydopamine (PDA)-modified sol-gel films. Effort was made to fabricate a PDA-modified sol-gel coating and a systematic investigation was conducted thereof. Long-term corrosion performance of this coating in 3.5 wt.% NaCl solution was evaluated through electrochemical impedance spectroscopy (EIS). Results show that the low-frequency impedance of the PDA-modified sol-gel coating remains significantly high at 7.9 × 10 5 Ω·cm 2 , even after 36 d of immersion in 3.5 wt.% NaCl medium, indicative of excellent protective properties. It notably surpasses low-frequency impedance of the unmodified coating, which registers at 2.5 × 10 4 Ω·cm 2 . The incorporation of PDA into the sol-gel coating, facilitated by adsorption and diffusion mechanisms, serves to fill micrometer- and nanometer-scale defects of the coating, thereby markedly enhancing their compactness. Furthermore, despite its modest thickness of 9 μm, the PDA-modified coating exhibits enduring corrosion protection capabilities.
研究领域:
材料科学
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表面工程
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腐蚀与防护
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纳米材料
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电化学
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DOI
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yangmin Wu,Wenjie Zhao,Sheng Liu,Liping Wang
Cellulose nanofiber was grafted on Ti 3 C 2 T x (Ti 3 C 2 T x @CNF) and then Ti 3 C 2 Tx@CNF nanohybrid acted as nanofiller to endow epoxy coating superior barrier property. Electrochemical tests and corrosion products revealed that incorporation of Ti 3 C 2 T x @CNF into epoxy could significantly improve its anti-corrosion performance. Even immersion in marine alternating hydrostatic pressure (AHP) environment for 240 h, the impedance modulus of composite coating was one order of magnitude higher as compared with controlled samples. Besides, cross-sectional structure confirmed that Ti 3 C 2 T x @CNF remarkable improve the compactness of coating and thus conferring active adhesion strength with twice higher than that of pure epoxy after 240 h immersion in AHP.
研究领域:
材料科学
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腐蚀工程
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纳米技术
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涂料与薄膜
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产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
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2025
·
IF 6.6
Bingqin Wang,Yadi Zhao,Ruichao Yan,Liangan Liu,Xuequn Cheng,Luntao Wang,Zhong Li,Chao Liu,Dawei Zhang,Xiaogang Li
In this study, 45 steel was taken as the research object, and a tin-iron alloy layer was prepared on its surface via a thermal diffusion tinning process. Combined with a series of characterization methods, the microstructure and element distribution of the thermal diffusion layer were systematically analyzed. Additionally, through cyclic immersion tests, electrochemical measurements, and outdoor exposure tests in marine atmosphere, the effects of thermal diffusion temperature and tin content in the diffusion agent on the structure and corrosion resistance of the thermal diffusion layer were systematically investigated. The results show that thermal diffusion tinning can form an alloy layer dominated by FeSn2 on the surface of 45 steel. Moreover, the higher the thermal diffusion temperature and the greater the tin content in the diffusion agent, the larger the thickness (up to 15 μm) and the better the compactness of the alloy layer. The corrosion resistance of the tinned steel is significantly better than that of 45 steel, and it is further improved with the increase of thermal diffusion temperature, tin content, and extension of thermal diffusion time. Among them, the tinned steel prepared under the thermal diffusion process of 80%-280°C-4h exhibits a corrosion current density of 4.027 μA · cm -2 , which is only 1/400 of that of 45 steel (12.095 μA · cm -2 ), and demonstrates the latest corrosion initiation and slowest development rate in marine atmospheric exposure. The key factors contributing to the improved corrosion resistance are the stable structure of FeSn 2 intermetallic compounds in the thermal diffusion layer, the physical barrier effect of the dense alloy layer, and the protective rust layer formed during the corrosion process.
研究领域:
材料科学
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腐蚀工程
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表面工程
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冶金学
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产品关联
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 42
·20030-20044
·
IF 6.97
Lin Hou,Dandan Chen,Lisha Hao,Chunyu Tian,Yingshan Yan,Ling Zhu,Huijuan Zhang,Yi Zhang,Zhenzhong Zhang
Cancer-associated fibroblasts (CAFs) are important barriers for nanoparticles (NPs) to deeply penetrate into tumors and severely limit the antitumor efficacy of nanomedicines. Herein, we proposed a CAF-triggered transformable drug delivery system based on a cleavable peptide responsive to fibroblast activation protein-α (FAP-α) specifically overexpressed on the surface of CAFs. The NPs were composed of cationic poly(amidoamine) (PAMAM) dendrimers cross-linked by our designed peptide, a chemotherapeutical drug was incorporated onto PAMAM using disulfide bonds and finally, hyaluronic acid (HA) was conjugated to improve the tumor targetability as well as biocompatibility through electrostatic interactions. These NPs had an initial size of ∼200 nm and negative zeta potential favorable for stable blood circulation; however, after docking with CAFs, they dissociated into smaller NPs and exposed the relative positive surface charge to facilitate penetration and enter the tumor cells together with CAFs. An interesting finding was that this system intracellularly released different levels of drugs in these two kinds of cells, which was beneficial for the disruption of the stromal barrier and increasing the local drug accumulation. Our investigation confirmed that the constructed system could alleviate the biological barriers and hold promising therapeutic efficiency for desmoplastic solid tumors.
研究领域:
纳米技术
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肿瘤学
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药学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Chang Li,Kang Tan,Fangzheng Hua,Changxue Wang,Xiaolin Wang,Fei Wang,Mengting Sun
Hydrate-based natural gas storage and transportation is in urgent need of efficient and eco-friendly promotion methods. Here, we employed a kind of eco-friendly hydrogels, which were polyvinyl alcohol-co-acrylic acid (PVA-co-PAA), as carriers for trace SDS solution to construct a co-promoter for methane hydrate formation. Under static condition without stirring, trace SDS solution that was lower than or equal to 0.4 mmol L −1 had no or had extremely weak promoting effects on hydrate formation kinetics, whereas hydrogel-carried trace SDS exhibited excellent synergistic promoting effects. The HS-0.4 under a SDS concentration of 0.4 mmol L −1 and at a swelling ratio of 200 g g −1 achieved the most remarkable promotion, and the induction time was 0 min, the hydrate growth rate at t 90 was 0.1552 ± 0.0068 mmol mL −1 min −1 , the methane uptake was 121.70 ± 1.58 mmol mol −1 and the water-to-hydrate conversion was 0.730 ± 0.009. During synergistic promotion process, on the one hand, hydrogels keeping with large surface area increased gas–liquid interface, and were in charge of facilitating hydrate nucleation and shortening induction time; on the other hand, trace SDS produced strong capillary effect and sharply boosted mass transfer during hydrate growth period, which drastically enhanced hydrate growth rate and methane uptake. Morphology observation on hydrate evolutions unveiled that the co-promoter significantly improved poor hydrate compactness and partly relieved foam problem caused by SDS. Hydrogel-carried trace SDS can serve as an effective, eco-friendly and economical promotion approach for methane hydrate formation, which might be of great benefit for hydrate-based natural gas storage and transportation.
研究领域:
化学工程
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材料科学
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环境科学
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能源存储与运输
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）